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    How Much Does It Cost To Build An Extension In London?

    September 29th, 2025

    For architects, contractors, and developers, the cost of a home extension in London depends on a host of factors, including specification, contractor size, design complexity, and other project-specific considerations.

     

    This guide outlines the key cost drivers you should discuss with clients, helping them understand not just the price, but also the impact of design choices on outcomes. 

     

    We’ve included a detailed breakdown by project elements to show the percentage of things like drainage, appliances, wiring to give clear picture of where budgets are allocated and where potential savings or upgrades can be considered.

    Extension Cost Calculations

    In our cost calculations, the following specifications have been assumed for all extensions:

     

    • The roof of the extension is pitched, rather than flat.
    • The structure is built using brick and block construction, rather than a timber frame.

     

    The extensions considered in these calculations include the following room configurations:

     

    • 20m² single-storey rear extension: comprising a dining room, utility room, and WC.
    • 20m² shell plus 40m² gross internal floor area (GIFA) wrap-around extension with ground-floor remodel: including a dining room, utility room, and WC.
    • 40m² double-storey rear extension: including a dining room, utility room, WC, an additional bedroom with en-suite bathroom, a storage room, and a small landing.

     

    In terms of build specification, BuildPartner gives you three broad options to choose from:

     

    • Basic spec is a basic finish; e.g., Leyland, Everest, Wickes.
    • Standard spec is a standard finish; e.g., Dulux, Hamilton, Slim Line.
    • Premium spec is a high-spec finish; e.g., Farrow & Ball, Fine Line, Siemens.

     

    In this article, we’ve provided a breakdown of the cost of building an extension to all three specifications. In addition, we have provided three different benchmarks to show the range of pricing you can expect among different contractors. These are: 

     

    • Low benchmark – smaller companies are generally lower cost but less specialised and with low project management function; good for low/mid-spec projects and tight budgets.
    • Mid benchmark – medium-sized companies offer a balanced mix of cost-effectiveness and specialisation; good for mid-range projects for effective execution within moderate budgets.
    • High benchmark – larger companies generally have a higher cost base but can handle a wide variety of specialist tasks; good for mid/high-spec projects and project management.

     

    The specification and benchmark you choose will have a major impact on the overall cost of building an extension, so it’s important to align them with your budget and the level of finish you’re aiming for.

     

    Cost Of Building A Single-Storey Rear Extension In London

    The table below shows the average cost of building a single-storey extension in London (20m2):

     

    Single-Storey Rear Extension Total Average Build Cost
    Low Benchmark Mid Benchmark High Benchmark
    Basic Spec £66,007  £73,808  £81,008 
    Standard Spec £70,430  £78,754  £86,437 
    Premium Spec £79,513  £88,910  £97,584 
    Average £71,983  £80,491  £88,343 

     

    The table below shows the average cost per square metre of building a single-storey extension in London (20m2):

     

    Single-Storey Rear Extension Average Cost Per Sq Metre
    Low Benchmark Mid Benchmark High Benchmark
    Basic Spec £3,300  £3,690  £4,050 
    Standard Spec £3,522  £3,938  £4,322 
    Premium Spec £3,976  £4,446  £4,879 
    Average £3,599  £4,025  £4,417 

    All costs exclude VAT.

     

    Here’s what the data shows for building a single-storey extension in London:

     

    • The minimum cost is £66,007, and the maximum cost is £97,584.
    • The total average cost is £80,491, or £4,025 per square metre.

    Start your free trial with BuildPartner to get a bespoke estimate of your construction project within minutes.

    Cost By Stages For Single-Storey Extension In London

    The table below shows the average cost by project stage for a single-storey extension in London (20m2):

     

    Total £78,754 100%
    Preliminaries £12,005 15.2%
    Foundations and substructure £9,302 11.8%
    External wall structure and lining £8,395 10.7%
    Roof structure and coverings £8,145 10.3%
    Steel and structural supports £4,916 6.2%
    Decoration £4,371 5.5%
    Floor preparation and finishes £4,239 5.4%
    Units, worktops and kitchen appliances £4,180 5.3%
    External windows and doors £4,092 5.2%
    Wired appliances £2,881 3.7%
    Floor structure and lining £2,526 3.2%
    Drainage and pipework £2,290 2.9%
    Internal wall structure and lining £2,123 2.7%
    Heating and cooling £1,891 2.4%
    Wall preparation and finishes £1,824 2.3%
    Internal doors and frames £1,369 1.7%
    Plumbed appliances £1,270 1.6%
    Demolitions £1,208 1.5%
    Wiring and fuseboards £546 0.7%
    Fixtures and fittings £427 0.5%
    Ceiling structure and lining £387 0.5%
    Ceiling preparation and finishes £367 0.5%

     

    Cost Of Building A Ground-Floor Wrap-Around Extension In London

    The table below shows the average cost of building a wrap-around extension and remodelling the ground-floor plan (20m² extension shell plus 40m² of gross internal floor area):

     

    Ground-Floor Wrap-Around Extension & Remodel Total Average Build Cost
    Low Benchmark Mid Benchmark High Benchmark
    Basic Spec £86,165  £97,772  £100,287 
    Standard Spec £98,105  £111,062  £113,696 
    Premium Spec £120,561  £136,056  £138,550 
    Average £101,611  £114,963  £117,511 

     

    The table below shows the average cost per square metre of building a wrap-around extension and remodelling the ground-floor plan (20m² extension shell plus 40m² of gross internal floor area):

     

    Ground-Floor Wrap-Around Extension & Remodel Average Cost Per Sq Metre
    Low Benchmark Mid Benchmark High Benchmark
    Basic Spec £2,154  £2,444  £2,507 
    Standard Spec £2,453  £2,777  £2,842 
    Premium Spec £3,014  £3,401  £3,464 
    Average £2,540  £2,874  £2,938 

    All costs exclude VAT.

     

    Here’s what the data shows for the cost of building a wrap-around extension and remodelling the floor plan:

     

    • The minimum cost is £86,165, and the maximum cost is £138,511.
    • The total average cost is £114,963, or £2,874 per square metre.

     

    Cost Of Building A Double-Storey Extension In London

    The table below shows the average cost of building a double-storey extension in London (40m2):

     

    Double-Storey Side Extension Total Average Build Cost
    Low Benchmark Mid Benchmark High Benchmark
    Basic Spec £117,257  £133,166  £136,417 
    Standard Spec £131,478  £148,994  £152,139 
    Premium Spec £156,600  £176,956  £180,102 
    Average £135,112  £153,039  £156,219 

     

    The table below shows the average cost of building a double-storey extension per square metre in London (40m2):

     

    Double-Storey Side Extension Average Cost Per Sq Metre
    Low Benchmark Mid Benchmark High Benchmark
    Basic Spec £2,931  £3,329  £3,410 
    Standard Spec £3,287  £3,725  £3,803 
    Premium Spec £3,915  £4,424  £4,503 
    Average £3,378  £3,826  £3,905 

    All costs exclude VAT.

     

    Here’s what the data shows for the cost of building a double-storey extension (40m2) in London:

     

    • The minimum cost is £117,257, and the maximum cost is £180,102.
    • The total average cost is £153,039, or £3,826 per square metre.

     

    Average Cost Of Building An Extension In London

    So, how much does it cost to build an extension in London? Based on the three types of builds covered in this article, it costs on average:

    • Single-Storey Rear Extension: £80,491, or £4,025 per square metre. 
    • Ground-Floor Wrap-Around Extension & Remodel: £114,963, or £2,874 per square metre.
    • Double-Storey Side Extension: £153,039, or £3,826 per square metre. 

    It’s also worth noting that your final cost could be lower or higher depending on the quality of materials you choose.

    Start your free trial with BuildPartner to get a bespoke estimate of your construction project within minutes.

    Please remember that all costs exclude VAT.

     

    Frequently Asked Questions About Building Extensions In London

    Here are some answers to frequently asked questions about building extensions in London.

    What are the challenges of building an extension on a Victorian terrace with no side access?

    Building an extension on a Victorian terraced house with no side access is perfectly achievable, but it presents some logistical challenges. Without an external route to the rear, all materials, tools, and waste must be carried through the house.

    With limited space for storage or skips, contractors may need street permits or timed deliveries, while strict London noise regulations can further slow the pace of work.

    Are there restrictions on building work hours in London?

    Most London boroughs limit noisy construction work to 8am to 6pm on weekdays and 8am to 1pm on Saturdays, with no loud work permitted on Sundays or bank holidays. 

    These hours are similar to those across most of the UK, but enforcement in London is usually tighter because homes are closer together and noise complaints are more common. 

    Are side return extensions suitable for terraced Victorian houses? 

    Yes, they’re very popular in London terraces. A side return extension fills the narrow space beside a kitchen or living area, creating extra usable space without extending too far into the garden. Rooflights or glass ceilings are often needed to ensure adjoining rooms get enough natural light.

    Are basement extensions still allowed in London?

    They are, but they’re heavily regulated due to flooding and structural risks. Boroughs like Kensington and Chelsea, Camden, and Westminster have strict basement policies limiting depth (around 3 to 4 metres below ground level).

    Developers usually need to submit detailed geological and structural surveys, plus a construction management plan showing how excavation, shoring, and water management will be handled.

    Do I need to inform Thames Water before building?

    If there’s a public sewer within 3 metres of your extension, you’ll need a Build-Over Agreement to ensure your construction won’t damage the sewer or block access for maintenance. 

    In London, where many Victorian and terraced homes connect to older public sewers, obtaining this agreement is quite common and should be factored into your planning process.

    You can check if a property is near a public sewer by contacting Thames Water or carrying out an asset location search on their website.

    Categories
    Blog

    How Much Does A Loft Conversion Cost In London?

    For many London properties, a loft conversion represents one of the most efficient ways to add space without extending the building’s footprint. But behind every well-executed loft conversion is a delicate balance where cost drives many of the structural and design decisions.

    This article breaks down the main cost components, offering a framework architects and developers can use to explain pricing to clients, compare basic, standard, and premium specifications, and benchmark costs across different-sized contractors to guide early design decisions.

    Main Types of Loft Conversions

    In this article, we’ll be reviewing three loft conversion types: a standard loft conversion, a dormer loft conversion, and a Mansard loft conversion:

    1. Standard Loft Conversion – Predominantly internal work without major changes like roof lifts or complete rebuilds.
    2. Dormer Loft Conversion – Extending the roof outward to create additional space and headroom; they can be full-width or smaller, depending on the space requirements.
    3. Mansard Loft Conversion – Altering the roof structure to create a near-vertical wall with a flat roof, providing maximum space and headroom.

    Other popular loft conversion types include the hip-to-gable and gable-to-gable conversions, which extend the roof to maximise space; shell conversions, which provide just the structural shell for homeowners to finish; roof lift conversions, which raise the entire roof for additional headroom; modular conversions, using prefabricated sections assembled on-site; and piggyback conversions, where a completely new storey is added on top of the existing roof.

    Loft Conversion Cost Calculations

    For reference, a fully finished attic generally matches the floor’s square footage. We have based our calculations on 20m² of floor space. In each example, we provide costs per square metre, so you can easily adjust the figures if your project is larger or smaller.

    All our calculations are based on a loft conversion comprising the following:

    • Master bedroom
    • En-suite bathroom
    • Eaves storage
    • Landing including stairs

    In terms of build specification, BuildPartner gives you three broad options to choose from:

    • Basic spec is a basic finish; e.g., Leyland, Everest, Wickes.
    • Standard spec is a standard finish; e.g., Dulux, Hamilton, Slim Line.
    • Premium spec is a high-spec finish; e.g., Farrow & Ball, Fine Line, Siemens.

    In this article, we’ve provided a breakdown of the cost of building a loft conversion to all three specifications. In addition, we have provided three different benchmarks to show the range of pricing you can expect among different contractors. These are: 

    • Low benchmark – smaller companies are generally lower cost but less specialised and with low project management function; good for low/mid-spec projects and tight budgets.
    • Mid benchmark – medium-sized companies offer a balanced mix of cost-effectiveness and specialisation; good for mid-range projects for effective execution within moderate budgets.
    • High benchmark – larger companies generally have a higher cost base but can handle a wide variety of specialist tasks; good for mid/high-spec projects and project management.

    The specification and benchmark you choose will have a major impact on the overall cost of building a loft conversion, so it’s important to align them with your budget and the level of finish you’re aiming for.

    Cost Of Building A Standard Loft Conversion In London

    The table below shows the average cost of building a standard loft conversion in London (20m2):

    Standard Loft Conversion Total Average Build Cost
    Low Benchmark Mid Benchmark High Benchmark
    Basic Spec £45,061 £51,257 £55,862
    Mid Spec £48,216 £54,639 £59,508
    Premium Spec £53,831 £61,063 £66,628
    Average £49,036 £55,653 £60,666

    The table below shows the average cost per square metre of building a standard loft conversion in London (20m2):

    Standard Loft Conversion Average Cost Per Sq Metre
    Low Benchmark Mid Benchmark High Benchmark
    Basic Spec £2,253 £2,563 £2,793
    Mid Spec £2,411 £2,732 £2,975
    Premium Spec £2,692 £3,053 £3,331
    Average £2,452 £2,783 £3,033

    All costs exclude VAT.

    Here’s what the data shows for building a standard loft conversion in London:

    • The minimum cost is £45,061, and the maximum cost is £66,628.
    • The total average cost is £55,653, or £2,783 per square metre.

    Start your free trial with BuildPartner to get a bespoke estimate of your construction project within minutes.

    Cost By Stages Of Loft Conversion In London

    The table below shows the average cost by project stage for a standard loft conversion in London (20m2):

    Total £54,639  100%
    Preliminaries £10,581 19.4%
    Steel and structural supports £6,854 12.5%
    External wall structure and lining £5,025 9.2%
    Internal wall structure and lining £3,770 6.9%
    Ceiling structure and lining £3,215 5.9%
    External windows and doors £3,085 5.6%
    Wall preparation and finishes £2,847 5.2%
    Floor structure and lining £2,790 5.1%
    Floor preparation and finishes £2,733 5.0%
    Plumbed appliances £2,588 4.7%
    Decoration £2,354 4.3%
    Wired appliances £1,945 3.6%
    Heating and cooling £1,541 2.8%
    Demolitions £1,440 2.6%
    Wiring and fuseboards £1,307 2.4%
    Internal doors and frames £1,147 2.1%
    Drainage and pipework £632 1.2%
    Fixtures and fittings £427 0.8%
    Ceiling preparation and finishes £358 0.7%

    Cost Of Building A Mansard Loft Conversion In London

    The table below shows the average cost of building a mansard loft conversion in London (20m²):

    Mansard Loft Conversion Total Average Build Cost
    Low Benchmark Mid Benchmark High Benchmark
    Basic Spec £66,783 £76,558 £81,924
    Mid Spec £69,938 £79,940 £85,570
    Premium Spec £75,553 £86,365 £92,690
    Average £70,758 £80,954 £86,728

    The table below shows the average cost per square metre of building a mansard loft conversion in London (20m²):

    Mansard Loft Conversion Average Cost Per Sq Metre
    Low Benchmark Mid Benchmark High Benchmark
    Basic Spec £3,339 £3,828 £4,096
    Mid Spec £3,497 £3,997 £4,279
    Premium Spec £3,778 £4,318 £4,635
    Average £3,538 £4,048 £4,336

    All costs exclude VAT.

    Here’s what the data shows for the cost of building a mansard loft conversion in London:

    • The minimum cost is £66,783, and the maximum cost is £92,690.
    • The total average cost is £80,954, or £4,048 per square metre.

    Cost Of Building A Dormer Loft Conversion In London

    The table below shows the average cost of building a dormer loft conversion in London (20m2):

    Dormer Loft Conversion Total Average Build Cost
    Low Benchmark Mid Benchmark High Benchmark
    Basic Spec £56,780 £65,012 £69,988
    Mid Spec £59,935 £68,394 £73,634
    Premium Spec £65,549 £74,819 £80,754
    Average £60,755 £69,408 £74,792

    The table below shows the average cost per square metre of building a dormer loft conversion in London (20m2):

    Dormer Loft Conversion Average Cost Per Sq Metre
    Low Benchmark Mid Benchmark High Benchmark
    Basic Spec £2,839 £3,251 £3,499
    Mid Spec £2,997 £3,420 £3,682
    Premium Spec £3,277 £3,741 £4,038
    Average £3,038 £3,470 £3,740

    All costs exclude VAT.

    Here’s what the data shows for the cost of building a dormer loft conversion in London:

    • The minimum cost is £56,780, and the maximum cost is £80,754.
    • The total average cost is £69,408, or £3,470 per square metre.

    Average Cost Of Loft Conversion In London

    So, how much does a loft conversion cost in London? Based on the three types of builds covered in this article, it costs on average:

    • Standard Loft Conversion: £55,653, or £2,783 per square metre. 
    • Mansard Loft Conversion: £80,954, or £4,048 per square metre.
    • Dormer Loft Conversion: £69,408, or £3,470 per square metre. 

    It’s also worth noting that your final cost could be lower or higher depending on the quality of materials you choose.

    Start your free trial with BuildPartner to get a bespoke estimate of your construction project within minutes.

    Please remember that all costs exclude VAT.

    Frequently Asked Questions About Loft Conversions In London

    Here are some answers to frequently asked questions about building loft conversions in London.

    What is the typical cost breakdown for a loft conversion in London?

    On average, labour accounts for the largest portion of a loft conversion budget in London: around 52% of total costs. Building materials make up roughly 31%, while finishing materials such as flooring, paint, and fixtures represent about 17%.

    In our standard loft conversion example, a total project costing £68,394 would equate to approximately £36,106 for labour, £20,800 for building materials, and £11,488 for finishes.

    How long does a loft conversion take? 

    A standard dormer loft typically takes 6 to 8 weeks from the start of construction. More complex designs such as mansard or L-shaped conversions can take up to 10 to 12 weeks. Design, approvals, and structural calculations usually add another 4 to 6 weeks before the build begins.

    Do I need a Party Wall Agreement?

    Yes, if your property shares a wall with a neighbour. Under the Party Wall etc. Act 1996, you must notify adjoining owners in writing before work begins. We can guide you through this process or recommend a local party wall surveyor.

    Older London homes (particularly Victorian and Edwardian terraces) often require additional planning and structural consideration, especially where roof spaces are shared or party walls are involved.

    Categories
    Blog

    How Much Does It Cost To Build A Garden Or Boundary Wall?

    September 29th, 2025

    When advising clients on external works, a frequent question you may face is: how much will it cost to build a garden wall? The answer isn’t straightforward, as you’ll no doubt be aware that the price depends on a range of factors: wall height, thickness, choice of bond, materials, foundation requirements, and site conditions. 

    This guide outlines the key cost drivers you should discuss with clients, helping them understand not just the price but also the structural integrity and aesthetic preferences. We’ve included example figures for one-and-a-half brick walls and two-brick walls to give a clear starting point for budgeting.

    Garden Wall Cost Calculations

    In our garden wall build cost calculations, we assume these walls are constructed in English bond, one of the most common brickwork types (see FAQs for information about the types of bonds). 

    Our example costings are based on a wall of 15m² (equivalent to 10 metres long at 1.5 metres high) and include twice-weathered coping stones for weather protection and a clean finish. We look at three examples comprising one-and-a-half brick walls and two-brick wide walls:

    • One brick wide: Typically used for low garden or boundary walls; cost-effective but not ideal for taller structures.
    • One and a half bricks wide: Greater stability; suitable for medium-height boundary walls or where extra durability is required.
    • Two bricks wide: Extremely strong; used for tall, freestanding, or retaining walls; more expensive in both materials and labour.

    In terms of build specification, BuildPartner gives you three broad options to choose from:

    • Basic spec is a basic finish; e.g., Leyland, Everest, Wickes.
    • Standard spec is a standard finish; e.g., Dulux, Hamilton, Slim Line.
    • Premium spec is a high-spec finish; e.g., Farrow & Ball, Fine Line, Siemens.

    In this article, we’ve provided a breakdown of the cost of building a garden wall to a standard specification. In addition, we have provided three different benchmarks to show the range of pricing you can expect among different contractors. These are: 

    • Low benchmark – smaller companies are generally lower cost but less specialised and with low project management function; good for low/mid-spec projects and tight budgets.
    • Mid benchmark – medium-sized companies offer a balanced mix of cost-effectiveness and specialisation; good for mid-range projects for effective execution within moderate budgets.
    • High benchmark – larger companies generally have a higher cost base but can handle a wide variety of specialist tasks; good for mid/high-spec projects and project management.

    The specification and benchmark you choose will have a major impact on the overall cost of building a boundary wall, so it’s important to align them with your budget and the level of finish you’re aiming for.

    Cost Of Building A One-and-a-Half Brick Wall – Facing Bricks

    The table below shows the average cost of building a one-and-a-half brick wall with facing bricks (15m2):

    One-and-Half
    Brick Wall
    (Facing Bricks)    		 Total Average Build Cost Average Cost Per Sq Metre
    Low Benchmark Mid Benchmark High Benchmark Low Benchmark Mid Benchmark High Benchmark
    East Anglia £4,569  £5,109  £5,607  £305  £341  £374 
    Greater London £4,820  £5,409  £5,915  £321  £361  £394 
    Inner London £4,941  £5,608  £6,015  £329  £374  £401 
    Midlands £4,528  £5,063  £5,557  £302  £338  £370 
    North England £4,705  £5,261  £5,774  £314  £351  £385 
    Northern Ireland £4,609  £4,988  £5,555  £302  £333  £370 
    Scotland £4,691  £5,245  £5,757  £313  £350  £384 
    South East £4,457  £4,984  £5,530  £323  £361  £396 
    South West £4,514  £5,181  £5,686  £309  £345  £379 
    Wales £4,395  £4,914  £5,271  £293  £328  £351 
    Average £4,623  £5,176  £5,667  £311  £348  £381 

    All costs exclude VAT.

    Here’s what the data shows for building a one-and-a-half brick wall with facing bricks:

    • The minimum cost is £4,395, and the maximum cost is £6,015.
    • The total average cost is £5,155, or £347 per square metre.

    Start your free trial with BuildPartner to get a bespoke estimate of your construction project within minutes.

    Cost Of Building A Two-Brick Wall – Facing Bricks

    The table below shows the average cost of building a two-brick wall with facing bricks (15m2):

    Two-Brick Wall
    (Facing Bricks)    		 Total Average Build Cost Average Cost Per Sq Metre
    Low Benchmark Mid Benchmark High Benchmark Low Benchmark Mid Benchmark High Benchmark
    East Anglia £7,712  £8,624  £9,465  £514  £575  £631 
    Greater London £8,083  £9,059  £9,920  £539  £604  £661 
    Inner London £8,306  £9,406  £10,112  £554  £627  £674 
    Midlands £7,651  £8,556  £9,390  £510  £570  £626 
    North England £7,914  £8,849  £9,712  £528  £590  £647 
    Northern Ireland £7,905  £8,853  £9,717  £528  £590  £648 
    Scotland £7,893  £8,826  £9,687  £526  £588  £646 
    South East £7,471  £8,354  £9,169  £541  £605  £664 
    South West £7,631  £8,730  £9,582  £521  £582  £639 
    Wales £7,455  £8,336  £8,925  £497  £556  £595 
    Average £7,802  £8,759  £9,568  £526  £589  £643 

    All costs exclude VAT.

    Here’s what the data shows for the cost of building a two-brick wall with facing bricks:

    • The minimum cost is £7,455, and the maximum cost is £10,122.
    • The total average cost is £8,710, or £586 per square metre.

    Cost Of Building A Two-Brick Wall – Premium Bricks

    The table below shows the average cost of building a two-brick wall (15m2) with premium bricks, such as limestone or sandstone bricks:

    All costs exclude VAT.Here’s what the data shows for the cost of building a two-brick wall (15m2) with premium bricks, such as limestone or sandstone bricks:

    • The minimum cost is £9,475, and the maximum cost is £12,593.
    • The total average cost is £11,083, or £739 per square metre.

    Average Cost Of Building A Boundary WallSo, how much does it cost to build a boundary wall in the UK? Based on the three types of builds covered in this article, it costs on average (when using a mid-benchmark contractor):

    • One-and-a-Half Brick Wall (Facing Bricks): £5,176, or £348 per square metre. 
    • Two-Brick Wall (Facing Bricks): £8,759, or £589 per square metre.
    • Two-Brick Wall (Limestone / Sandstone): £11,162, or £744 per square metre. 

    It’s also worth noting that these projects were based on a standard specification, so your final cost could be lower or higher depending on the quality of materials you choose.Start your free trial with BuildPartner to get a bespoke estimate of your construction project within minutes.Please remember that all costs exclude VAT.Frequently Asked Questions About Building A Boundary WallHere are some answers to frequently asked questions about building boundary walls.What is the best brick type for a boundary wall?Facing bricks are a popular choice for visible boundary walls because they look good and weather well. Engineering bricks, on the other hand, are stronger, denser, and more resistant to frost and water penetration, making them ideal for foundations or damp-prone areas.For a more premium finish, natural stone such as limestone or sandstone can be used, which are exceptionally durable and enhance the character of a property. Reclaimed bricks are also growing in popularity, but they should be checked for strength before use.What are the main types of brick bonds (patterns) for boundary walls?The three most common brick bonds are:

    • Stretcher bond: bricks laid with their long face showing in each course. While its simple and economical, it’s only suitable for half-brick-thick walls (decorative or low walls).
    • English bond: alternating courses of stretchers (long face) and headers (short face). Strong, traditional, and ideal for one-brick-thick structural walls.
    • Flemish bond: each course alternates stretchers and headers, creating a distinctive pattern. More decorative but requires greater skill and time to lay.

    Other bonds, such as stack bond or header bond, exist but are less common in boundary walls as they are generally weaker or used for specific design purposes.Why would I build a wall two bricks wide?Two-brick-thick walls (around 450 mm) are used for extra strength and stability, often in retaining walls or very tall boundary walls. They can also be required in areas exposed to high winds.What are once-weathered and twice-weathered coping stones?When finishing the top of a boundary or garden wall, coping stones are needed for protecting the wall from rain and frost. The two most common types are:

    • Once-weathered coping stones: These have a single sloped surface that is angled away from the wall to shed rainwater. 
    • Twice-weathered coping stones: These have two slopes (a top slope and a chamfered or angled underside) which direct water away from the top and sides of the wall.

    The main distinction is in how the stone is angled to shed water. Twice-weathered coping stones are generally considered more durable and premium.

    Two-Brick Wall
    (Premium Bricks)    		 Total Average Build Cost Average Cost Per Sq Metre
    Low Benchmark Mid Benchmark High Benchmark Low Benchmark Mid Benchmark High Benchmark
    East Anglia £9,890  £11,059  £12,138  £659  £737  £809 
    Greater London £10,261  £11,494  £12,593  £684  £766  £840 
    Inner London £10,583  £11,940  £12,143  £706  £796  £810 
    Midlands £9,829  £10,991  £12,063  £655  £733  £804 
    North England £10,092  £11,284  £12,385  £673  £752  £826 
    Northern Ireland £9,890  £11,059  £12,138  £659  £737  £809 
    Scotland £10,071  £11,261  £12,360  £671  £751  £824 
    South East £9,475  £10,594  £11,754  £632  £706  £784 
    South West £9,809  £11,166  £12,255  £654  £744  £817 
    Wales £9,633  £10,771  £11,499  £642  £718  £767 
    Average £9,953  £11,162  £12,133  £664  £744  £809 
    Categories
    Blog

    How Much Does It Cost To Build A Driveway?

    September 29th, 2025

    When planning client projects, accurately estimating the cost of a driveway depends on factors such as surface material, driveway size, sub-base preparation, drainage, and labour. 

    As a contractor or architect, you’ll need to balance aesthetics, durability, and budget, whether the specification calls for block paving, tarmac, gravel, or premium natural stone finishes. 

    This guide outlines the main cost drivers and provides a regional breakdown across the UK, helping you give precise estimates and informed recommendations to clients based on local material prices, labour rates, and site conditions.

    Building A Driveway Cost Calculations

    In our driveway build cost calculations, we assume a double driveway of 25m². This includes removing shrubs and undergrowth, excavating subsoil, installing a membrane and hardcore, and adding concrete edging.

    In terms of build specification, BuildPartner gives you three broad options to choose from:

    • Basic spec is a basic finish; e.g., Leyland, Everest, Wickes.
    • Standard spec is a standard finish; e.g., Dulux, Hamilton, Slim Line.
    • Premium spec is a high-spec finish; e.g., Farrow & Ball, Fine Line, Siemens.

    In this article, we’ve provided a breakdown of the cost of building a driveway to a standard specification. In addition, we have provided three different benchmarks to show the range of pricing you can expect among different contractors. These are: 

    • Low benchmark – smaller companies are generally lower cost but less specialised and with low project management function; good for low/mid-spec projects and tight budgets.
    • Mid benchmark – medium-sized companies offer a balanced mix of cost-effectiveness and specialisation; good for mid-range projects for effective execution within moderate budgets.
    • High benchmark – larger companies generally have a higher cost base but can handle a wide variety of specialist tasks; good for mid/high-spec projects and project management.

    The specification and benchmark you choose will have a major impact on the overall cost of building a driveway, so it’s important to align them with your budget and the level of finish you’re aiming for.

    Cost Of Building A Gravel Driveway

    The table below shows the average cost of building a gravel driveway (25m2):

    Gravel Driveway Total Average Build Cost Average Cost Per Sq Metre
    Low Benchmark Mid Benchmark High Benchmark Low Benchmark Mid Benchmark High Benchmark
    East Anglia £3,433  £3,839  £4,213  £137  £154  £169 
    Greater London £3,479  £3,891  £4,270  £139  £156  £171 
    Inner London £3,516  £4,049  £4,103  £141  £162  £164 
    Midlands £3,243  £3,626  £3,980  £130  £145  £159 
    North England £3,558  £3,978  £4,366  £142  £159  £175 
    Northern Ireland £3,323  £3,579  £3,977  £130  £143  £159 
    Scotland £3,406  £3,809  £4,181  £136  £152  £167 
    South East £3,224  £3,605  £3,999  £140  £157  £172 
    South West £3,276  £3,791  £4,161  £136  £152  £166 
    Wales £3,162  £3,536  £3,807  £126  £141  £152 
    Average £3,362  £3,770  £4,106  £136  £152  £165 

    All costs exclude VAT.

    Here’s what the data shows for building a gravel driveway (25m2):

    • The minimum cost is £3,162, and the maximum cost is £4,366.
    • The total average cost is £3,746, or £151 per square metre.

    Start your free trial with BuildPartner to get a bespoke estimate of your construction project within minutes.

    Cost Of Building A Tarmac Driveway

    The table below shows the average cost of building a tarmac driveway (25m2):

    Tarmac Driveway Total Average Build Cost Average Cost Per Sq Metre
    Low Benchmark Mid Benchmark High Benchmark Low Benchmark Mid Benchmark High Benchmark
    East Anglia £3,802  £4,251  £4,666  £152  £170  £187 
    Greater London £3,842  £4,296  £4,715  £154  £172  £189 
    Inner London £3,903  £4,471  £4,531  £156  £179  £181 
    Midlands £3,605  £4,031  £4,424  £144  £161  £177 
    North England £3,870  £4,327  £4,749  £155  £173  £190 
    Northern Ireland £3,664  £3,930  £4,374  £143  £157  £175 
    Scotland £3,765  £4,210  £4,620  £151  £168  £185 
    South East £3,565  £3,986  £4,375  £155  £173  £190 
    South West £3,641  £4,206  £4,616  £150  £168  £185 
    Wales £3,521  £3,937  £4,230  £141  £157  £169 
    Average £3,718  £4,164  £4,530  £150  £168  £183 

    All costs exclude VAT.

    Here’s what the data shows for the cost of building a tarmac driveway (25m2):

    • The minimum cost is £3,521, and the maximum cost is £4,749.
    • The total average cost is £4,137, or £167 per square metre.

    Cost Of Building A Block Paving Driveway

    The table below shows the average cost of building a block paving driveway (25m2):

    Block Paving Driveway Total Average Build Cost Average Cost Per Sq Metre
    Low Benchmark Mid Benchmark High Benchmark Low Benchmark Mid Benchmark High Benchmark
    East Anglia £4,149  £4,639  £5,092  £166  £186  £204 
    Greater London £4,203  £4,700  £5,158  £168  £188  £206 
    Inner London £4,239  £4,891  £4,963  £170  £196  £199 
    Midlands £3,883  £4,342  £4,766  £155  £174  £191 
    North England £4,241  £4,742  £5,205  £170  £190  £208 
    Northern Ireland £4,156  £4,647  £5,100  £166  £186  £204 
    Scotland £4,104  £4,589  £5,037  £164  £184  £201 
    South East £3,912  £4,375  £4,854  £156  £175  £194 
    South West £3,939  £4,596  £5,044  £158  £184  £202 
    Wales £3,768  £4,213  £4,542  £151  £169  £182 
    Average £4,059  £4,573  £4,976  £162  £183  £199 

    All costs exclude VAT.

    Here’s what the data shows for the cost of building a block paving driveway (25m2):

    • The minimum cost is £3,768, and the maximum cost is £5,205.
    • The total average cost is £4,536, or £181 per square metre.

    Cost Of Building A Natural Stone Paving Driveway

    The table below shows the average cost of building a natural stone paving driveway (25m2):

    Natural Stone Paving Driveway Total Average Build Cost Average Cost Per Sq Metre
    Low Benchmark Mid Benchmark High Benchmark Low Benchmark Mid Benchmark High Benchmark
    East Anglia £6,048  £6,763  £7,423  £242  £271  £297 
    Greater London £6,102  £6,823  £7,489  £244  £273  £300 
    Inner London £6,224  £7,101  £7,173  £249  £284  £287 
    Midlands £5,782  £6,466  £7,096  £231  £259  £284 
    North England £6,140  £6,865  £7,535  £246  £275  £301 
    Northern Ireland £6,017  £6,728  £7,384  £241  £269  £295 
    Scotland £6,003  £6,713  £7,367  £240  £269  £295 
    South East £5,659  £6,328  £7,021  £226  £253  £281 
    South West £5,838  £6,719  £7,375  £234  £269  £295 
    Wales £5,667  £6,336  £6,786  £227  £253  £271 
    Average £5,948  £6,684  £7,265  £238  £267  £291 

    All costs exclude VAT.

    Here’s what the data shows for the cost of building a natural stone paving driveway (25m2):

    • The minimum cost is £5,659, and the maximum cost is £7,535.
    • The total average cost is £6,632, or £265 per square metre.

    Average Cost Of Building A Driveway

    So, how much does it cost to build a driveway in the UK? Based on the four types of builds covered in this article, it costs on average (when using a mid-benchmark contractor):

    • Gravel Driveway: £3,770, or £152 per square metre. 
    • Tarmac Driveway: £4,164, or £168 per square metre.
    • Block Paving Driveway: £4,573, or £183 per square metre. 
    • Natural Stone Paving Driveway: £6,684, or £267 per square metre.

    It’s also worth noting that these projects were based on a standard specification, so your final cost could be lower or higher depending on the quality of materials you choose. Drainage, lighting, gates, and bollards are not included in these estimates.

    Start your free trial with BuildPartner to get a bespoke estimate of your construction project within minutes.

    Please remember that all costs exclude VAT.

    Frequently Asked Questions About Building A Driveway

    Here are some answers to frequently asked questions about building a driveway.

    How large should a double driveway be?

    A standard double driveway is typically 5m wide by 5m long, or about 25m², providing enough space for two cars side by side with clearance for manoeuvring.

    Do I need to add drainage to a driveway?

    Drainage is particularly beneficial if the driveway is on an incline or slopes toward the house. Installing channels or French drains prevents water pooling and reduces the risk of water entering the property.

    What are the load-bearing properties of different driveway surfaces?

    Different driveway surfaces handle vehicle weight and environmental conditions in different ways, which can affect wear and tear:

    • Tarmac: Suitable for standard cars and light commercial vehicles. However, it can soften in high heat and may rut under frequent heavy loads.
    • Block Paving: Very durable, especially in herringbone patterns, which provide great load distribution for heavier vehicles.
    • Concrete Slabs: High compressive strength and great for heavy vehicles. Risk of cracking if sub-base or expansion joints are inadequate, so installation quality is critical.
    • Natural Stone: Extremely durable under load. However, it is expensive, requires skilled labour, and can shift or crack if bedding and sub-base aren’t carefully prepared.

    Also, options like resin-bound gravel are growing in popularity. You can choose from a variety of colours and finishes. Not only that, but they also offer greater permeability to prevent water pooling.

    Categories
    Building Costs Blog

    How Much Does It Cost To Build And Install A Dormer Window?

    August 28th, 2025

    A dormer window offers a straightforward way to improve spatial efficiency, natural light, and overall property value, while also improving kerb appeal. When planning your project, it’s important to think beyond the design and consider the cost implications. Location, roof type, and finish choices can all swing the budget significantly.

     

    But how much does it cost to build a dormer window on an existing property? In this guide, we break down typical installation costs to help you weigh up your options. We’ve included example figures for both flat-roof and pitched-roof dormers to give a clear starting point for budgeting.

     

    Dormer Window Cost Calculations

    In our dormer window cost calculations, we’ve included the cost of fitting new radiators under each window to help with heat distribution and reduce cold spots. We also include making good internally with plastering and painting, along with a professional clean once the work is complete.

     

    In terms of build specification, BuildPartner gives you three broad options to choose from:

     

    • Basic spec is a basic finish; e.g., Leyland, Everest, Wickes.
    • Standard spec is a standard finish; e.g., Dulux, Hamilton, Slim Line.
    • Premium spec is a high-spec finish; e.g., Farrow & Ball, Fine Line, Siemens.

     

    In this article, we’ve provided a breakdown of the cost of building a dormer window to a standard specification. In addition, we have provided three different benchmarks to show the range of pricing you can expect among different contractors. These are:

    • Low benchmark – smaller companies are generally lower cost but less specialised and with low project management function; good for low/mid-spec projects and tight budgets.
    • Mid benchmark – medium-sized companies offer a balanced mix of cost-effectiveness and specialisation; good for mid-range projects for effective execution within moderate budgets.
    • High benchmark – larger companies generally have a higher cost base but can handle a wide variety of specialist tasks; good for mid/high-spec projects and project management.

     

    The specification and benchmark you choose will have a major impact on the overall cost, so it’s important to align them with your budget and the level of finish you’re aiming for.

     

    Cost Of Building A Dormer Window With Flat Roof

    The table below shows the average cost of building a dormer window with a flat roof to a standard specification:

     

    Dormer Window – Flat Roof Total Average Build Cost Average Cost Per Sq Metre
    Low Benchmark Mid Benchmark High Benchmark Low Benchmark Mid Benchmark High Benchmark
    East Anglia £7,494  £8,379  £9,197  £1,873  £2,095  £2,299 
    Greater London £7,714  £8,752  £9,335  £1,928  £2,188  £2,334 
    Inner London £7,463  £8,486  £8,809  £1,866  £2,122  £2,202 
    Midlands £7,009  £7,837  £8,602  £1,752  £1,959  £2,150 
    North England £7,525  £8,415  £9,236  £1,881  £2,104  £2,309 
    Northern Ireland £7,234  £7,793  £8,767  £1,786  £1,948  £2,192 
    Scotland £7,324  £8,190  £8,989  £1,831  £2,047  £2,247 
    South East £6,974  £7,755  £8,652  £1,895  £2,107  £2,326 
    South West £7,042  £8,062  £8,850  £1,803  £2,015  £2,213 
    Wales £6,872  £7,684  £8,301  £1,718  £1,921  £2,075 
    Average £7,265  £8,135  £8,874  £1,833  £2,051  £2,235 

    All costs exclude VAT.

     

    Here’s what the data shows for building a dormer window with a flat roof:

     

    • The minimum cost is £6,872, and the maximum cost is £9,335.
    • The total average cost is £8,091, or £2,040 per square metre.

     

    Cost Breakdown By Element – Inner London

    The table below shows a detailed breakdown of the typical costs involved in building a dormer window in Inner London. It highlights the main elements, including materials, labour, finishing touches, and contractor overheads and profits.

    Elements Cost %
    Total £7,684.04  100%
    External wall finishes £1,677.39  21.8%
    External wall lining £951.34  12.4%
    Hoarding £717.07  9.3%
    Professional cleaning £683.91  8.9%
    External wall structure £585.23  7.6%
    Radiator under window £481.91  6.3%
    Roof structure £362.89  4.7%
    Paint to ceiling £291.83  3.8%
    Ceiling preparation £249.13  3.2%
    Roof coverings £233.85  3.0%
    Rainwater drainage £229.47  3.0%
    Roof lining £210.35  2.7%
    Scaffolding £209.10  2.7%
    Flashing £203.20  2.6%
    Paint to walls £177.40  2.3%
    Internal wall preparation £158.18  2.1%
    Heavy demolition £121.74  1.6%
    Ceiling lining £101.58  1.3%
    Medium demolition £  38.47  0.5%

     

    Start your free trial with BuildPartner to get a bespoke estimate of your construction project within minutes.

    Cost Of Building A Dormer Window With Pitched Roof

    The table below shows the average cost of building a dormer window with a pitched roof to a standard specification:

     

    Dormer Window – Pitched Roof Total Average Build Cost Average Cost Per Sq Metre
    Low Benchmark Mid Benchmark High Benchmark Low Benchmark Mid Benchmark High Benchmark
    East Anglia £8,050  £9,002  £9,880  £2,013  £2,250  £2,470 
    Greater London £8,359  £9,487  £10,067  £2,090  £2,372  £2,517 
    Inner London £8,034  £9,125  £9,486  £2,009  £2,281  £2,371 
    Midlands £7,560  £8,454  £9,278  £1,890  £2,113  £2,320 
    North England £8,087  £9,043  £9,925  £2,022  £2,261  £2,481 
    Northern Ireland £7,787  £8,391  £9,440  £1,923  £2,098  £2,360 
    Scotland £7,883  £8,815  £9,675  £1,971  £2,204  £2,419 
    South East £7,539  £8,384  £9,252  £2,049  £2,278  £2,514 
    South West £7,592  £8,694  £9,544  £1,944  £2,173  £2,386 
    Wales £7,407  £8,283  £8,948  £1,852  £2,071  £2,237 
    Average £7,830  £8,768  £9,550  £1,976  £2,210  £2,407 

    All costs exclude VAT.

     

    Here’s what the data shows for the cost of building a dormer window with a pitched roof:

     

    • The minimum cost is £7,407, and the maximum cost is £10,067.
    • The total average cost is £8,716, or £2,198 per square metre.

     

    Cost Of Building A Double Dormer Window

    The table below shows the average cost of building two dormer windows with pitched roofs to a standard specification:

     

    Double Dormer Windows – Pitched Roofs Total Average Build Cost Average Cost Per Sq Metre
    Low Benchmark Mid Benchmark High Benchmark Low Benchmark Mid Benchmark High Benchmark
    East Anglia £13,993  £15,646  £17,173  £  1,749  £  1,956  £  2,147 
    Greater London £14,578  £16,546  £17,549  £  1,822  £  2,068  £  2,194 
    Inner London £13,996  £15,889  £16,469  £  1,750  £  1,986  £  2,059 
    Midlands £13,211  £14,772  £16,213  £  1,651  £  1,847  £  2,027 
    North England £14,104  £15,771  £17,310  £  1,763  £  1,971  £  2,164 
    Northern Ireland £13,822  £15,455  £16,963  £  1,728  £  1,932  £  2,120 
    Scotland £13,794  £15,424  £16,929  £  1,724  £  1,928  £  2,116 
    South East £13,148  £14,619  £16,312  £  1,644  £  1,827  £  2,039 
    South West £13,267  £15,211  £16,697  £  1,658  £  1,901  £  2,087 
    Wales £12,928  £14,456  £15,597  £  1,616  £  1,807  £  1,950 
    Average £13,684  £15,379  £16,721  £  1,711  £  1,922  £  2,090 

    All costs exclude VAT.

     

    Here’s what the data shows for the cost of building two dormer windows with pitched roofs:

    • The minimum cost is £12,928, and the maximum cost is £17,549.
    • The total average cost is £15,261, or £1,908 per square metre.

     

    Average Cost Of Building A Dormer Window

    So, how much does it cost to build a dormer window in the UK? Based on the three types of installations covered in this article, it costs on average (when using a mid-benchmark contractor):

    • Dormer window – flat roof: £8,315, or £2,051 per square metre. 
    • Dormer window – pitched roof: £8,768, or £2,210 per square metre.
    • Double dormer windows – pitched roofs: £15,379, or £1,922 per square metre. 

    It’s also worth noting that these projects were based on a standard specification, so your final cost could be lower or higher depending on the quality of materials you choose.

    Start your free trial with BuildPartner to get a bespoke estimate of your construction project within minutes.

    Please remember that all costs exclude VAT.

    Frequently Asked Questions About Building A Dormer Window

    Here are some answers to frequently asked questions about installing dormer windows.

    How long does it take to install a dormer window?

    Installing a dormer window usually takes around two to three weeks from start to finish. The main build involves fitting the dormer frame and window into the roof, followed by moving any central heating or radiator pipework.

    Once the window is in place, the interior is plastered, left to dry for several days, and then decorated before the radiator is hung. While the construction itself can take about a week, drying times and decoration mean it’s usually a couple of weeks before the space is ready to use.

    What are the different types of dormer windows?

    Dormer windows come in several styles, each with its own unique look and purpose:

    1. Gable-fronted dormer – pitched roof with two sloping sides forming a peak.
    2. Hip roof dormer – three sloping sides that blend into the roofline.
    3. Flat roof dormer – flat top, maximising interior space and headroom.
    4. Shed dormer – single sloping roof extending from the main roof.
    5. Eyebrow dormer – curved, wave-like roof for a decorative look.
    6. Arched dormer – rounded top that softens the roofline.

    The main types you see in the UK are gable-fronted, flat roof, and shed dormers because they are the most cost-effective and provide extra space.

    Do I need guttering on my dormer window?

    Guttering is usually recommended for large dormer windows to properly manage rainwater runoff, but they’re not essential on smaller windows as water naturally drains without causing problems. Flat roof dormers are more likely to need guttering to prevent water pooling. 

    Is scaffolding required to build a dormer window?

    Scaffolding is almost always necessary, even if some of the work can be done from the inside. This is because building the dormer involves external tasks like removing roof tiles, cutting rafters, and fitting lead flashing. 

    UK regulations also mandate scaffolding for prolonged work at height to ensure safety. Additionally, scaffolding makes handling heavy materials like timber and glazing much easier and safer.

    Categories
    Building Costs Blog

    How Much Does It Cost To Build A Roof Terrace?

    September 29th, 2025

    When advising clients on external works, a frequent question you may face is: how much will it cost to build a garden wall? The answer isn’t straightforward, as you’ll no doubt be aware that the price depends on a range of factors: wall height, thickness, choice of bond, materials, foundation requirements, and site conditions. 

    This guide outlines the key cost drivers you should discuss with clients, helping them understand not just the price but also the structural integrity and aesthetic preferences. We’ve included example figures for one-and-a-half brick walls and two-brick walls to give a clear starting point for budgeting.

     

    Garden Wall Cost Calculations

    In our garden wall build cost calculations, we assume these walls are constructed in English bond, one of the most common brickwork types (see FAQs for information about the types of bonds). 

    Our example costings are based on a wall of 15m² (equivalent to 10 metres long at 1.5 metres high) and include twice-weathered coping stones for weather protection and a clean finish. We look at three examples comprising one-and-a-half brick walls and two-brick wide walls:

    • One brick wide: Typically used for low garden or boundary walls; cost-effective but not ideal for taller structures.
    • One and a half bricks wide: Greater stability; suitable for medium-height boundary walls or where extra durability is required.
    • Two bricks wide: Extremely strong; used for tall, freestanding, or retaining walls; more expensive in both materials and labour.

    In terms of build specification, BuildPartner gives you three broad options to choose from:

    • Basic spec is a basic finish; e.g., Leyland, Everest, Wickes.
    • Standard spec is a standard finish; e.g., Dulux, Hamilton, Slim Line.
    • Premium spec is a high-spec finish; e.g., Farrow & Ball, Fine Line, Siemens.

    In this article, we’ve provided a breakdown of the cost of building a garden wall to a standard specification. In addition, we have provided three different benchmarks to show the range of pricing you can expect among different contractors. These are: 

    • Low benchmark – smaller companies are generally lower cost but less specialised and with low project management function; good for low/mid-spec projects and tight budgets.
    • Mid benchmark – medium-sized companies offer a balanced mix of cost-effectiveness and specialisation; good for mid-range projects for effective execution within moderate budgets.
    • High benchmark – larger companies generally have a higher cost base but can handle a wide variety of specialist tasks; good for mid/high-spec projects and project management.

    The specification and benchmark you choose will have a major impact on the overall cost of building a boundary wall, so it’s important to align them with your budget and the level of finish you’re aiming for.

    Cost Of Building A One-and-a-Half Brick Wall – Facing Bricks

    The table below shows the average cost of building a one-and-a-half brick wall with facing bricks (15m2):

    One-and-Half
    Brick Wall
    (Facing Bricks)    		 Total Average Build Cost Average Cost Per Sq Metre
    Low Benchmark Mid Benchmark High Benchmark Low Benchmark Mid Benchmark High Benchmark
    East Anglia £4,569  £5,109  £5,607  £305  £341  £374 
    Greater London £4,820  £5,409  £5,915  £321  £361  £394 
    Inner London £4,941  £5,608  £6,015  £329  £374  £401 
    Midlands £4,528  £5,063  £5,557  £302  £338  £370 
    North England £4,705  £5,261  £5,774  £314  £351  £385 
    Northern Ireland £4,609  £4,988  £5,555  £302  £333  £370 
    Scotland £4,691  £5,245  £5,757  £313  £350  £384 
    South East £4,457  £4,984  £5,530  £323  £361  £396 
    South West £4,514  £5,181  £5,686  £309  £345  £379 
    Wales £4,395  £4,914  £5,271  £293  £328  £351 
    Average £4,623  £5,176  £5,667  £311  £348  £381 

    All costs exclude VAT.

    Here’s what the data shows for building a one-and-a-half brick wall with facing bricks:

    • The minimum cost is £4,395, and the maximum cost is £6,015.
    • The total average cost is £5,155, or £347 per square metre.

    Start your free trial with BuildPartner to get a bespoke estimate of your construction project within minutes.

    Cost Of Building A Two-Brick Wall – Facing Bricks

    The table below shows the average cost of building a two-brick wall with facing bricks (15m2):

    Two-Brick Wall
    (Facing Bricks)    		 Total Average Build Cost Average Cost Per Sq Metre
    Low Benchmark Mid Benchmark High Benchmark Low Benchmark Mid Benchmark High Benchmark
    East Anglia £7,712  £8,624  £9,465  £514  £575  £631 
    Greater London £8,083  £9,059  £9,920  £539  £604  £661 
    Inner London £8,306  £9,406  £10,112  £554  £627  £674 
    Midlands £7,651  £8,556  £9,390  £510  £570  £626 
    North England £7,914  £8,849  £9,712  £528  £590  £647 
    Northern Ireland £7,905  £8,853  £9,717  £528  £590  £648 
    Scotland £7,893  £8,826  £9,687  £526  £588  £646 
    South East £7,471  £8,354  £9,169  £541  £605  £664 
    South West £7,631  £8,730  £9,582  £521  £582  £639 
    Wales £7,455  £8,336  £8,925  £497  £556  £595 
    Average £7,802  £8,759  £9,568  £526  £589  £643 

    All costs exclude VAT.

    Here’s what the data shows for the cost of building a two-brick wall with facing bricks:

    • The minimum cost is £7,455, and the maximum cost is £10,122.
    • The total average cost is £8,710, or £586 per square metre.

    Cost Of Building A Two-Brick Wall – Premium Bricks

    The table below shows the average cost of building a two-brick wall (15m2) with premium bricks, such as limestone or sandstone bricks:

    Two-Brick Wall
    (Premium Bricks)    		 Total Average Build Cost Average Cost Per Sq Metre
    Low Benchmark Mid Benchmark High Benchmark Low Benchmark Mid Benchmark High Benchmark
    East Anglia £9,890  £11,059  £12,138  £659  £737  £809 
    Greater London £10,261  £11,494  £12,593  £684  £766  £840 
    Inner London £10,583  £11,940  £12,143  £706  £796  £810 
    Midlands £9,829  £10,991  £12,063  £655  £733  £804 
    North England £10,092  £11,284  £12,385  £673  £752  £826 
    Northern Ireland £9,890  £11,059  £12,138  £659  £737  £809 
    Scotland £10,071  £11,261  £12,360  £671  £751  £824 
    South East £9,475  £10,594  £11,754  £632  £706  £784 
    South West £9,809  £11,166  £12,255  £654  £744  £817 
    Wales £9,633  £10,771  £11,499  £642  £718  £767 
    Average £9,953  £11,162  £12,133  £664  £744  £809 

    All costs exclude VAT.

    Here’s what the data shows for the cost of building a two-brick wall (15m2) with premium bricks, such as limestone or sandstone bricks:

    • The minimum cost is £9,475, and the maximum cost is £12,593.
    • The total average cost is £11,083, or £739 per square metre.

    Average Cost Of Building A Boundary Wall

    So, how much does it cost to build a boundary wall in the UK? Based on the three types of builds covered in this article, it costs on average (when using a mid-benchmark contractor):

    • One-and-a-Half Brick Wall (Facing Bricks): £5,176, or £348 per square metre. 
    • Two-Brick Wall (Facing Bricks): £8,759, or £589 per square metre.
    • Two-Brick Wall (Limestone / Sandstone): £11,162, or £744 per square metre. 

    It’s also worth noting that these projects were based on a standard specification, so your final cost could be lower or higher depending on the quality of materials you choose.

    Start your free trial with BuildPartner to get a bespoke estimate of your construction project within minutes.

    Please remember that all costs exclude VAT.

    Frequently Asked Questions About Building A Boundary Wall

    Here are some answers to frequently asked questions about building boundary walls.

    What is the best brick type for a boundary wall?

    Facing bricks are a popular choice for visible boundary walls because they look good and weather well. Engineering bricks, on the other hand, are stronger, denser, and more resistant to frost and water penetration, making them ideal for foundations or damp-prone areas.

    For a more premium finish, natural stone such as limestone or sandstone can be used, which are exceptionally durable and enhance the character of a property. Reclaimed bricks are also growing in popularity, but they should be checked for strength before use.

    What are the main types of brick bonds (patterns) for boundary walls?

    The three most common brick bonds are:

    • Stretcher bond: bricks laid with their long face showing in each course. While its simple and economical, it’s only suitable for half-brick-thick walls (decorative or low walls).
    • English bond: alternating courses of stretchers (long face) and headers (short face). Strong, traditional, and ideal for one-brick-thick structural walls.
    • Flemish bond: each course alternates stretchers and headers, creating a distinctive pattern. More decorative but requires greater skill and time to lay.

    Other bonds, such as stack bond or header bond, exist but are less common in boundary walls as they are generally weaker or used for specific design purposes.

    Why would I build a wall two bricks wide?

    Two-brick-thick walls (around 450 mm) are used for extra strength and stability, often in retaining walls or very tall boundary walls. They can also be required in areas exposed to high winds.

    What are once-weathered and twice-weathered coping stones?

    When finishing the top of a boundary or garden wall, coping stones are needed for protecting the wall from rain and frost. The two most common types are:

    • Once-weathered coping stones: These have a single sloped surface that is angled away from the wall to shed rainwater. 
    • Twice-weathered coping stones: These have two slopes (a top slope and a chamfered or angled underside) which direct water away from the top and sides of the wall.

    The main distinction is in how the stone is angled to shed water. Twice-weathered coping stones are generally considered more durable and premium.

    Categories
    Industry Insights Blog

    Feasibility Study vs Detailed Schedule Of Costs: What’s The Difference?

    When planning a project, there’s often a moment where you need to pause and ask: do we need a feasibility study, or are we ready to produce a detailed schedule of costs? They serve very different purposes, yet they’re often confused (and sometimes skipped altogether).

    A feasibility study helps you determine whether a project is financially, operationally, technically, and legally viable before committing too much time or money. Whereas, a detailed schedule of costs is a thorough, itemised breakdown of exactly what the project will cost.

    In this article, we’ll break down the differences between the two services, explore when each is appropriate, and explain how they both support better decision-making.

    Start your free trial with BuildPartner to get a bespoke estimate of your construction project within minutes.

    What Is A Feasibility Study?

    Ultimately, a feasibility study is an early-stage assessment that determines whether a proposed project is viable. It helps avoid costly mistakes by testing assumptions before major commitments are made.

    Typical areas covered include:

    • Site constraints (planning, environmental, access)
    • Approximate calculations of quantities and materials
    • Design options and scope outlines
    • Stakeholder needs and risks
    • Regulatory and planning considerations

    Feasibility studies provide broad-brushstroke cost estimates to guide initial project decisions.

    They tell you whether to proceed with a project or go back to the drawing board to overcome any obstacles. For instance, the inclusion of additional bathrooms or underfloor heating might push the project over budget, prompting a rethink around necessities versus nice-to-haves.

    A BuildPartner feasibility study includes approximate quantity calculations of each stage and area of a project, standard materials and finishes, and local market pricing. It’s carried out by a qualified, insured scheduler.

    All projects can benefit from a feasibility study. Why invest in a detailed schedule upfront when a feasibility study can provide a reliable reality check on budget for a fraction of the cost? 

    This helps avoid unnecessary costs and supports informed decisions early on.

    When Do You Need A Feasibility Study?

    A feasibility study is most valuable at the very start of a project, often even before any drawings are produced, and certainly before significant design work, planning submissions, or funding applications take place.

    You might consider a feasibility study if:

    • The site, scope, or budget is still unclear
    • You’re comparing project options or land uses
    • External factors (e.g., planning, utilities, access) might derail the project
    • You need to test viability before seeking funding or client sign-off

    A feasibility study is often created at RIBA Stage 2 or 3 of a construction project (see FAQs for more info), but they can also be done at Stage 0 and 1. It helps stakeholders say no early or move forward with more clarity. 

    Need a feasibility study? We can provide expert support and collaborate with architects to deliver detailed drawings too.
    Contact us at estimating@buildpartner.com 

    What Is A Detailed Schedule Of Costs?

    A detailed schedule of costs is a comprehensive, itemised breakdown of what a project will cost, based on an agreed design and scope. 

    It includes:

    • Line-by-line breakdown of materials and labour
    • Subcontractor and supplier pricing
    • Project timeline of each project stage

    Unlike feasibility estimates, these are based on real figures and design intent. And accuracy matters; even a minor error or omission can lead to major cost overrun, such as the misplacement of a decimal point and ordering 120m² of tiles instead of 12m².

    A BuildPartner schedule of costs involves a detailed calculation of quantities, application of local market prices, and thorough research and inclusion of specified materials and their costs. 

    How does that compare with a feasibility study?

    Well, a feasibility study might estimate patio doors for a 3m-wide opening, including materials and labour, at £3,200. While a detailed schedule of costs might detail specific bifold patio doors with integrated blinds, totalling £5,500.

    In short, the feasibility study provides a broad estimate for early planning; the schedule of costs delivers an exact financial plan for construction.

    Both services are carried out by qualified, insured schedulers at BuildPartner.

    If you need a feasibility study or a specified cost schedule, please contact us at estimating@buildpartner.com

    When Do You Need A Detailed Schedule Of Costs?

    A detailed schedule of costs is usually prepared after technical drawings are completed, as these provide the detailed information needed for accurate cost quantification.

    A detailed cost schedule is needed when:

    • The design is developed enough to quantify accurately
    • You’re preparing for a tender or engaging with contractors
    • A lender, investor, or funding body needs transparent cost data

    The schedule of costs is often created at RIBA Stage 4 of a construction project (see FAQs for more info), after the technical design. From then on in, it becomes a financial control tool, not just a pricing exercise. 

    For large projects, cost schedules may be created and revised throughout, especially at the tender stage, contract signing, and post-tender negotiations.

    Key Differences At A Glance

    The table below highlights the main differences between a feasibility study and a detailed schedule of costs:

    Aspect Feasibility Study Detailed Schedule of Costs
    Purpose Early-stage cost planning and viability testing Detailed cost planning and accurate quoting
    Timing Pre-design or concept stage Post-design, when scope is fixed
    Detail Level Approximate quantities; standard materials Detailed quantities; specified materials and finishes
    Materials & Finishes Standard materials and finishes applied Researched and populated with specified products and suppliers
    Pricing Basis Local market prices with standard rates Bespoke rates, local prices, and detailed supplier quotes
    Use Case Exploring feasibility, securing early buy-in Accurate pricing for contracting, tender, or funding
    Prepared By Qualified and insured BuildPartner scheduler Qualified and insured BuildPartner scheduler
    Cost 

    (BuildPartner)

    		 0.1% of project value (e.g., £200 on £200k project) Minimum charge: £150 Qualified and insured BuildPartner scheduler

    0.2% of project value (e.g., £400 on £200k project)

    Minimum charge: £300

    How They Complement Each Other

    Despite the comparison in the table above, feasibility studies and detailed cost schedules aren’t competing services. They’re part of the same planning journey. Think of it like this:

    • Feasibility studies explore what’s possible.
    • Specified schedules define the actual costs.

    In essence, a feasibility study is part of an iterative approach to pricing. At the outset, you get a rough cost based on the project scope and surface area. Then, if it’s within budget, you can carry out a specified schedule to home in on cost and accuracy.

    So the two aren’t mutually exclusive services.

    If you skip the feasibility study, you risk implementing impractical designs; and if you rush into a cost schedule without agreeing on a defined scope, you can expect to see wild revisions at a later stage. 

    Starting this process earlier minimises potential waste on architectural costs.

    Choosing the Right Service For The Stage You’re In

    Selecting between a feasibility study and a detailed schedule of costs all boils down to timing. If your project is still in its early stages, with variables like site conditions, planning risk, or design scope not yet fixed, you probably need a feasibility study before committing. 

    Once the scope is clear and design decisions are locked in, a detailed cost schedule will provide you with a detailed breakdown needed for accurate quoting. 

    If you need a feasibility study or a specified cost schedule, please contact us at estimating@buildpartner.com. We also collaborate with architects to deliver detailed drawings too.

    Frequently Asked Questions About Feasibility Studies & Cost Schedules

    Here are some answers to frequently asked questions about feasibility studies and cost schedules in construction projects.

    How accurate are feasibility studies compared to full-cost schedules?

    Feasibility studies are indicative. They might be within 10 to 20% of final costs, or even greater if the project scope changes drastically. 

    Detailed schedules aim for much greater accuracy, often within 5 to 10%, providing no unexpected issues arise, such as unforeseen site conditions or design changes.

    Do feasibility studies include detailed material specs?

    Feasibility studies tend to use standard assumptions and typical finishes. Specific material choices and supplier pricing are included later in the detailed schedule. 

    At the feasibility stage, the goal is to check if the project makes sense without sweating the small stuff like picking Dulux over Crown paint or choosing specific types of fixtures. It’s about obtaining ballpark figures, not nailing down exact brands or suppliers.

    Who typically carries out feasibility studies and cost schedules? 

    Feasibility studies can be undertaken by architects, planners, or cost consultants like BuildPartner. Detailed cost schedules are usually prepared by a quantity surveyor or specialist consultants. Working with experienced, insured professionals ensures the figures stand up to scrutiny.

    Why is it important to have a qualified and insured scheduler? 

    A qualified scheduler ensures your cost plan is based on accurate quantities and a professional understanding of construction methods and pricing. 

    Being insured adds a layer of protection; if there’s a significant error or omission, there is clear path to addressing disputes and legal challenges.

    Can I skip the feasibility study and go straight to a cost schedule? 

    Only if the project scope, site, and design are fully defined, otherwise you risk pricing the wrong thing or hitting roadblocks later. 

    Skipping the feasibility study can lead to false confidence in costings and timeframes. Doing so ultimately risks the possibility of incurring expensive revisions down the line.

    What is the RIBA Plan of Work?

    The RIBA Plan of Work 2020 was developed by the Royal Institute of British Architects, and it provides a structured framework for managing architectural and construction projects in the UK. The framework organises building projects into eight stages: 

    • Stage 0: Strategic Definition – Define objectives, business case, and feasibility. 
    • Stage 1: Preparation and Briefing – Develop project brief, budget, and site appraisals. 
    • Stage 2: Concept Design – Create initial designs and preliminary cost estimates. 
    • Stage 3: Spatial Coordination – Refine design, develop specifications, and planning. 
    • Stage 4: Technical Design – Finalise detailed designs and tender documents. 
    • Stage 5: Manufacturing and Construction – Oversee construction and manage progress. 
    • Stage 6: Handover – Complete construction, hand over the building, and address defects. 
    • Stage 7: Use – Monitor performance and conduct post-occupancy evaluations.

    A feasibility study is usually carried out at Stage 2 or 3, but it’s not unusual to carry one out sooner at Stage 0 or 1. A detailed cost schedule is typically developed after the technical design at Stage 4. 

    Categories
    Industry Insights Blog

    The 7 Benefits Of Feasibility Studies In Construction Projects

    July 28th, 2025

    Before any plans are drawn up, the very first step in any successful construction project should be a feasibility study. A thorough study evaluates whether a proposed build is financially, operationally, technically, and legally possible.

    A feasibility study assesses everything from cost estimation to planning risks, site conditions to legal constraints. With that, architects, project managers, and consultants can make informed decisions early in the process, saving time, money, and frustration down the line.

    In this article, we’ll explore seven key benefits of feasibility studies in construction and why skipping this stage could be a costly mistake.

    1. Providing Clearer Budget Estimates

    A feasibility study sets a realistic baseline for costs. It forces early analysis of design, materials, planning fees, and site issues. Without one, budgets are based on assumptions, not facts.

    An evidence-based estimate determines how much capital is needed (and at what stage), which is really important for clients to understand so they can secure access to funding in advance.

    If the money runs out due to unexpected costs, the project stalls. A feasibility study turns budgeting from guesswork into strategy and helps keep the project financially on track from start to finish.

    2. Avoiding Cost Overrun

    Globally, 9 out of 10 construction projects exceed budget, with an average overrun of around 28%. In the UK, around 70% of major infrastructure schemes overrun projected costs. So whether it’s a small home extension or a large infrastructure scheme, no project is immune to budget overruns.

    Estimating errors and flawed cost projections are responsible for nearly 60% of cost overruns in construction projects.

    An early feasibility report pinpoints cost risks before they arise. With BuildPartner Construction Pricing Software, you get an accurate, itemised breakdown of every element in your project.

    Simply enter your project details, and the system pulls thousands of live prices from an up-to-date database for all the materials required based on your floorplans.

    It even includes small components and not just the obvious building materials (like bricks and mortar), but also preliminaries like skips, fixtures and fittings, and sundry items.

    This level of transparency significantly reduces the risk of inaccurate estimates, something that’s all too common when manually entering costs line by line in a spreadsheet.

    3. Testing A Project’s Financial Viability

    A feasibility study is your first layer of financial due diligence. It helps you decide whether a project is worth pursuing and financially viable. By identifying all the associated costs early, it enables informed decisions before you commit to costly planning or construction.

    For residential or personal projects, the focus is on usability and lifestyle benefits rather than financial gain, but the feasibility study still ensures that the project remains within budget.

    When it comes to commercial developments, a properly conducted feasibility study determines whether the project is likely to deliver a worthwhile return on investment, which is especially important for developers, investors, and funding partners.

    4. Planning Ahead For Challenges

    A feasibility study identifies potential timeline risks, helping you anticipate delays and develop strategies to keep your project on schedule and within budget. For client satisfaction, it must be delivered on time and in full.

    Here are some of the challenges a feasibility study can help identify and plan for:

    • Regulatory delays, e.g., slow planning permission or conservation area restrictions.
    • Site conditions, e.g., flood risk, unstable ground, or access issues for machinery.
    • Supply issues, e.g., long lead times or reliance on imported materials.
    • Labour shortages, e.g., lack of qualified bricklayers or electricians in the area.
    • Budget risks, e.g., unexpected utility connection fees or underpriced preliminaries.
    • Stakeholder objections, e.g., local residents opposing height, noise, or traffic impact.

    So it’s not just about financial feasibility. A thorough study gives you a holistic view of the project’s operational viability, too, and keeps it running according to its critical path.

    Start your free trial with BuildPartner to get a bespoke estimate of your construction project within minutes.

    5. Improving Client Confidence

    When clients see all the challenges and solutions laid out clearly from the start, they gain confidence that the project will be managed responsibly and delivered as promised.

    When using BuildPartner, users can invite clients to the main dashboard to see a view of costs by:

    • Stages – drainage, decoration, heating, roofing, etc.
    • Areas – kitchen, bedroom, bathroom, etc.

    Clients can also view a detailed breakdown of building materials, finishing materials, and labour costs across three scenarios—low, mid, and high benchmark contractors—along with the project timeline.

    This transparency assures clients that every stage and aspect of the project has been fully costed, minimising the risk of unexpected expenses later.

    If any costs do arise, they’ll clearly understand what was included and agreed upon from the start. That protects both sides: clients trust the process, and contractors aren’t blamed for unexpected surprises.

    6. Prioritising Project Elements

    A feasibility study allows you to make flexible decisions about building materials and components from the start. This way, you can adjust the scope or budget early on, preventing costs from spiralling out of control.

    For example, with BuildPartner, at the click of a button, you can change a project’s specification:

    • Basic spec is a basic finish; e.g., Leyland, Everest, Wickes.
    • Standard spec is a standard finish; e.g., Dulux, Hamilton, Slim Line.
    • Premium spec is a high-spec finish; e.g., Farrow & Ball, Fine Line, Siemens.

    And in the Schedule, you can choose from a range of options for any individual building material:

    You can adjust the specification based on what matters to each individual client. For example, one client may choose to reduce spending on kitchen fittings to free up budget for higher-end flooring. Another might scale back on fitted wardrobes in order to invest in underfloor heating.

    This flexibility helps keep the overall budget in check and allows clients to make trade-offs without compromising on the features that matter most to them.

    7. Helping Obtain Planning Permission

    A feasibility study can flag local planning constraints early. These might include height limits, boundary rules, or conservation area restrictions. You can then shape the design to meet planning policy, meaning you’re more likely to get approval the first time.

    For example, there’s no point commissioning architectural drawings for a three-storey townhouse if the feasibility study reveals it would block sunlight to neighbouring properties and contravene local planning rules. In that case, the study might point you toward a two-storey design that meets daylight requirements.

    The feasibility study ensures time and money aren’t wasted on designs that won’t get built.

    Start your free trial with BuildPartner to get a bespoke estimate of your construction project within minutes.

    Feasibility Studies Save Time, Money, and Stress

    By clarifying what’s possible, what it will cost, and what risks need managing, a feasibility study helps you make informed decisions before money is spent on drawings and applications.

    Whether residential or commercial, starting with a feasibility study puts you in control. It allows you to adjust specifications and building materials to focus on what matters most in order to stay within budget.

    Frequently Asked Questions About Feasibility Studies

    Here are some answers to frequently asked questions about feasibility studies in construction projects.

    How do feasibility studies influence project timelines?

    Feasibility studies give you foresight. For example, if you’re relying on a special component like hemp bricks (or any bespoke materials), a thorough study will establish if enough material is available and can be delivered on time. After all, without those bricks, the build can’t proceed and the whole project would come to a halt.

    What does a feasibility study include?

    Typically, it covers cost estimates, timeline analysis, site constraints, regulatory requirements, and risk assessments. Some feasibility studies concentrate primarily on financial aspects, such as cost estimates, budget alignment, and return on investment.

    Can feasibility studies help with securing financing?

    A thorough feasibility study provides lenders and investors with reliable data on costs, risks, and expected returns. Mortgage lenders usually ask for a detailed cost plan to assess the viability and risk of self-build projects, especially when the client is funding it personally.

    When should a feasibility study be done?

    A feasibility study should be completed early, ideally before architectural designs are drawn up or planning applications submitted. It helps iron out the project’s particulars and scope to ensure designs align with budget and planning requirements

    Categories
    Building Costs Blog

    How Much Does It Cost To Build A Garden Office? UK Cost Guide 2025

    July 28th, 2025

    As demand for home-based workspaces and creative studios continues to rise, garden offices have become a staple of modern residential projects.

     

    While some clients opt for modular or temporary structures, long-term value lies in a properly constructed building, one that won’t rattle or shake in every gale, is well insulated for year-round comfort, keeps pests out, and won’t suffer from damp or leaks.

     

    But how much does it cost to build an office in a garden? In this guide, we’ll break down the installation costs so you can weigh up the options, including with and without a WC and kitchenette that includes:

     

    • Sink with mixer tap
    • Base unit with a small worktop
    • Under-counter fridge
    • Microwave
    • Basic storage for cups, cutlery, and dry goods

     

    We also provide a basic example with a felt roof system and engineered wood floor—two straightforward swaps that can help reduce the overall project cost and make the build more budget-friendly.

     

     

    Garden Office Cost Calculations

    The costs in this guide are based on a garden office comprising 12m2. We’ve also included a cost per square metre, so you can easily work out the costs for similar projects.

    In terms of build specification, BuildPartner gives you three broad options to choose from:

     

    • Basic spec is a basic finish; e.g., Leyland, Everest, Wickes.
    • Standard spec is a standard finish; e.g., Dulux, Hamilton, Slim Line.
    • Premium spec is a high-spec finish; e.g., Farrow & Ball, Fine Line, Siemens.

     

    In this article, we’ve provided a breakdown of the cost of building a garden office to a standard specification. In addition, we have provided three different benchmarks to show the range of pricing you can expect among different contractors. These are:

     

    • Low benchmark – smaller companies are generally lower cost but less specialised and with low project management function; good for low/mid-spec projects and tight budgets.
    • Mid benchmark – medium-sized companies offer a balanced mix of cost-effectiveness and specialisation; good for mid-range projects for effective execution within moderate budgets.
    • High benchmark – larger companies generally have a higher cost base but can handle a wide variety of specialist tasks; good for mid/high-spec projects and project management.

     

    The specification and benchmark you choose will have a major impact on the overall cost, so it’s important to align them with your budget and the level of finish you’re aiming for.

     

    Cost Of Building A Garden Office With Kitchenette & WC

    The table below shows the average cost of building a garden office that includes a kitchenette and a separate WC:

     

    Garden Office – With Kitchenette & WC Total Average Build Cost Average Cost Per Sq Metre
    Low Benchmark Mid Benchmark High Benchmark Low Benchmark Mid Benchmark High Benchmark
    East Anglia £40,821 £45,645 £50,098 £3,402 £3,804 £4,175
    Greater London £43,573 £50,168 £54,601 £3,631 £4,181 £4,550
    Inner London £44,420 £50,018 £51,977 £3,702 £4,168 £4,331
    Midlands £39,605 £44,285 £48,606 £3,300 £3,690 £4,050
    North England £38,615 £43,179 £47,391 £3,218 £3,598 £3,949
    Northern Ireland £39,723 £43,138 £48,530 £3,295 £3,595 £4,044
    Scotland £39,902 £44,618 £48,970 £3,325 £3,718 £4,081
    South East £39,592 £43,983 £49,119 £3,586 £3,984 £4,401
    South West £39,970 £46,104 £50,606 £3,436 £3,842 £4,217
    Wales £38,705 £43,280 £46,536 £3,225 £3,607 £3,878
    Average £40,493 £45,442 £49,643 £3,412 £3,819 £4,168

    All costs exclude VAT.        

     

    Here’s what the data shows for building a garden office that includes a kitchenette and a separate WC:

     

    • It costs 8% more to build in Inner London.
    • The minimum cost is £38,615, and the maximum cost is £54,601.
    • The total average cost is £45,193, or £3,800 per square metre.

     

    Start your free trial with BuildPartner to get a bespoke estimate of your construction project within minutes.

    Cost Of Building A Garden Office Without Kitchenette & WC

    The table below shows the average cost of building a garden office without a kitchenette and a separate WC (as per the example above):

     

    Garden Office – No Kitchenette or WC Total Average Build Cost Average Cost Per Sq Metre
    Low Benchmark Mid Benchmark High Benchmark Low Benchmark Mid Benchmark High Benchmark
    East Anglia £28,940 £32,360 £35,518 £2,412 £2,697 £2,960
    Greater London £30,789 £35,507 £38,523 £2,566 £2,959 £3,210
    Inner London £31,376 £35,379 £36,667 £2,615 £2,948 £3,056
    Midlands £28,099 £31,420 £34,486 £2,342 £2,618 £2,874
    North England £27,257 £30,479 £33,452 £2,271 £2,540 £2,788
    Northern Ireland £28,138 £30,690 £34,526 £2,344 £2,558 £2,877
    Scotland £28,144 £31,471 £34,541 £2,345 £2,623 £2,878
    South East £27,986 £31,097 £34,347 £2,535 £2,817 £3,111
    South West £28,293 £32,705 £35,899 £2,438 £2,725 £2,992
    Wales £27,336 £30,566 £32,848 £2,278 £2,547 £2,737
    Average £28,636 £32,167 £35,081 £2,415 £2,703 £2,948

     All costs exclude VAT.

     

    Here’s what the data shows for the cost of building a garden office without a kitchenette and a separate WC:

     

    • The minimum cost is £27,251, and the maximum cost is £38,523.
    • The total average cost is £31,961, or £2,689 per square metre.

     

    Cost Of Building A Garden Office Using Felt Roof & Laminate Floor

    The table below shows the average cost of building a garden office (without WC and kitchenette) using a felt roof system instead of roof tiles, and laminate flooring in place of engineered oak—two straightforward swaps that can help reduce the overall project cost and make the build more budget-friendly.

     

    Garden Office – With Felt Roof System & Laminate Floor Total Average Build Cost Average Cost Per Sq Metre
    Low Benchmark Mid Benchmark High Benchmark Low Benchmark Mid Benchmark High Benchmark
    East Anglia £25,962 £29,030 £31,862 £2,163 £2,419 £2,655
    Greater London £27,608 £31,758 £34,429 £2,301 £2,647 £2,869
    Inner London £28,069 £31,719 £32,818 £2,339 £2,643 £2,735
    Midlands £25,178 £28,154 £30,901 £2,098 £2,346 £2,575
    North England £24,415 £27,300 £29,964 £2,035 £2,275 £2,497
    Northern Ireland £23,927 £26,754 £29,364 £1,994 £2,230 £2,447
    Scotland £25,146 £28,118 £30,861 £2,095 £2,343 £2,572
    South East £25,062 £27,876 £31,092 £2,088 £2,323 £2,591
    South West £25,374 £29,339 £32,205 £2,114 £2,445 £2,684
    Wales £24,507 £27,403 £29,449 £2,042 £2,284 £2,454
    Average £25,525 £28,745 £31,294 £2,127 £2,395 £2,608

     All costs exclude VAT.

     

    Here’s what the data shows for the cost of building a garden office with a felt roof system (instead of tiles) and using laminate flooring (instead of engineered oak):

     

    • The minimum cost is £23,927, and the maximum cost is £34,429.
    • The total average cost is £28,521, or £2,377 per square metre.

     

    Average Cost Of Building A Garden Office

    So, how much does it cost to build a garden office in the UK? Based on the three types of installations covered in this article, it costs on average (when using a mid-benchmark contractor):

    • Garden Office – With Kitchenette & WC: £45,442, or £3,819 per square metre.
    • Garden Office – No Kitchenette or WC: £32,167, or £2,703 per square metre.
    • Garden Office – Felt Roof System & Laminate Floor: £28,745, or £2,395 per square metre.

    These figures show just how much the total cost can vary depending on the type and scope of your project. Key factors include whether you include a kitchenette or WC, and whether you opt for more affordable finishes like flooring and roofing.

    It’s also worth noting that these projects were based on a standard specification, so your final cost could be lower or higher depending on the quality of materials you choose.

    Start your free trial with BuildPartner to get a bespoke estimate of your construction project within minutes. Please remember that all costs exclude VAT.

     

    Frequently Asked Questions About Building A Garden Office

    Here are some answers to frequently asked questions about building a garden office.

    Are garden offices cheaper than house extensions or loft conversions?

    Garden offices are generally cheaper because they avoid the expensive structural work required for house extensions and loft conversions.

    Quite often, their foundations aren’t connected to the main house, so there’s no need to knock through walls or install steel beams and supporting walls, which saves on labour, materials, and the cost of making good plasterwork, painting, flooring, and decoration.

    Plumbing is often unnecessary for a garden office, and you’ll likely avoid the time and cost of full planning applications.

    Do I need planning permission to build a garden office?

    In most cases, garden offices can usually be built under Permitted Development Rights, meaning you don’t need formal planning permission. However, it must be a single storey, take up less than 50% of your garden, and not be used as a separate living space. A height limit of 2.5m applies (if it’s within 2 metres of a boundary).

    If your property is listed, in a conservation area, or you plan to run a business with regular visitors, you may need permission. It’s always best to double-check with your local planning authority.

    Is it possible to make a garden office completely off-grid?

    To make a garden office completely off-grid, you’ll need solar panels with battery storage for power, and a rainwater harvesting and filtration system for potable water (for making hot drinks and washing up).

    The biggest challenge is the toilet. Without drainage or plumbing, your only real option is a composting toilet… not exactly everyone’s preferred choice.

    Composting toilets use a carbon additive like sawdust to break down waste, but disposal is a bit of a chore. It’s far more convenient to simply pop inside to use the nearest bathroom. As for the internet, your existing Wi-Fi with a signal booster should keep you reliably connected.

    What if there is limited access to the garden for construction equipment?

    This is a common issue for Victorian terraces and even some newbuilds where the garden is only accessible through the house or a narrow side passage. In most cases, it’s still possible to build a garden office, it just requires a bit more planning.

    Many contractors will carry materials through the house and use protective floor coverings to avoid damage. However, limited access can increase labour time and delivery costs slightly, so it’s worth flagging this early during quotes and site surveys.

    If carrying out the work during rain, expect mess to be tracked through the house, so additional cleaning and protective measures may be needed to keep the property tidy. It’s also a good idea to factor in the cost of a professional upon completion.

    Does a garden office change a property’s council tax band?

    A garden room or office usually doesn’t affect the property’s council tax band because it’s considered an outbuilding, not part of your main living space. Council tax bands are based on the internal floor area of the primary residence, so standalone garden offices are typically excluded.

    Categories
    Building Costs Blog

    How Much Does It Cost To Remove A Chimney Breast & Chimney Stack?

    June 27th, 2025

     

    Planning to remove a chimney breast or stack, either in your own home or for a client? Whether you’re opening up space for a modern layout or getting rid for other practical reasons (such as preventing leaks), this guide provides the typical costs associated with chimney breast and chimney stack removal.

     

    We’ll look at the building costs by region and also an itemised breakdown of the associated tasks, including things like:

     

    • Scaffolding for safe access
    • Acrow props for temporary structural support
    • Demolition and removal of the stack or breast
    • Timber hoarding and materials lifts for site logistics
    • Roof repairs, including tiles, insulation, and lead flashing

     

    Before reviewing the costs, it’s important to distinguish the two parts of a chimney that are often confused:

     

    • Chimney Breast (Internal) – The part that projects into a room, usually to house a fireplace, running vertically through the inside of the building.
    • Chimney Stack (External) – The visible part of the chimney that sits above the roofline. It often contains one or more flues and may serve fireplaces on different floors.

     

    Here’s how the costs typically stack up, along with what you can expect during the removal process, specifically for projects in the UK in 2025.

     

    Chimney Breast Removal Cost Calculations

    In terms of build specification, BuildPartner gives you three broad options to choose from:

     

    • Basic spec is a basic finish; e.g., Leyland, Everest, Wickes.
    • Standard spec is a standard finish; e.g., Dulux, Hamilton, Slim Line.
    • Premium spec is a high-spec finish; e.g., Farrow & Ball, Fine Line, Siemens.

     

    In this article, we’ve provided a breakdown of the costs according to a standard specification. In addition, we have provided three different benchmarks to show the range of pricing you can expect among different contractors:

     

    • Low benchmark – smaller companies are generally lower cost but less specialised and with low project management function; good for low/mid-spec projects and tight budgets.
    • Mid benchmark – medium-sized companies offer a balanced mix of cost-effectiveness and specialisation; good for mid-range projects for effective execution within moderate budgets.
    • High benchmark – larger companies generally have a higher cost base but can handle a wide variety of specialist tasks; good for mid/high-spec projects and project management.

     

    The specification and benchmark you choose will have a major impact on the overall cost of chimney breast and stack removal, so it’s important to align them with both your budget and the level of finish you’re aiming for.

    Cost Of Removing A Chimney Stack

    The table below shows the average cost of removing a chimney stack in different regions throughout the UK:

    Removal of Chimney Stack & Roof Repair (External) Total Average Build Cost
    Low Benchmark Mid Benchmark High Benchmark
    East Anglia £3,739 £4,181 £4,589
    Greater London £4,018 £4,797 £4,863
    Inner London £4,062 £4,699 £4,743
    Midlands £3,611 £4,038 £4,432
    North England £3,530 £3,947 £4,332
    Northern Ireland £3,703 £4,614 £4,101
    Scotland £3,647 £4,078 £4,475
    South East £3,614 £3,994 £4,484
    South West £3,657 £4,248 £4,662
    Wales £3,515 £3,930 £4,222
    Average £3,710 £4,253 £4,490

    All costs exclude VAT.        

     

    Here’s what the data shows for removing a chimney stack:

     

    • It costs 8% more to remove a chimney stack in Inner London.
    • The minimum cost is £3,515, and the maximum cost is £4,863.
    • The total average cost is £4,151.

     

    Start your free trial with BuildPartner to get a bespoke estimate of your construction project within minutes.

     

    Chimney Stack Removal Elements – Inner London

    The table below shows the cost of the associated tasks with removing a chimney stack, for Inner London:

     Task  Specifications  Cost
     Preliminaries £3,030
    Skip 8-yard skip £384
    Materials lift Geni SLA15 363kg £282
    Timber hoarding OSB hoarding with built-in door and timber lock £857
    Scaffold roof Scaffold to roof £87
    Scaffolding to elevations (m2) Simple Scaffold £705
    Acrow propping (650mm spacing) Supply and install temporary propping £716
     Demolitions £825
    Strip out chimney stack above roofline £825
     Roof structure and coverings £844
    Timber pitched roof structure 47x150mm roof rafters @400 c/c £185
    Wood sheathing to roof 18mm Structural Hardwood Plywood Sheet £77
    Breather membrane to roof Tyvek Supro breather membrane £12
    Insulation to roof between rafters 140mm Kingspan Thermaroof TR26 Insulation £180
    Timber battens to roof 38x38mm timber battens £97
    Cement tiles to roof Mid spec (PC Supply £22/m2) £186
    Ridge tiles; butt jointed; bedding/pointing Concrete/cement ridge tile (PC Supply £15/m) £38
    Sand and cement to tiled verge Sand and cement to tiled verge £7
    Lead flashing Lead Code 4 – 300mm Roofing Lead Flashing Roll £63

     

    Cost Of Removing Ground Floor Chimney Breast – Single Storey

    The table below shows the average cost of removing a chimney breast (single storey) in different regions throughout the UK:

     

    Ground Floor Chimney Breast Removal – Single Storey (Internal) Total Average Build Cost
    Low Benchmark Mid Benchmark High Benchmark
    East Anglia £4,640 £5,188 £5,695
    Greater London £4,945 £5,958 £6,133
    Inner London £5,047 £5,871 £5,935
    Midlands £4,452 £4,978 £5,463
    North England £4,351 £4,865 £5,340
    Northern Ireland £4,602 £5,122 £5,762
    Scotland £4,509 £5,041 £5,533
    South East £4,499 £4,999 £5,522
    South West £4,522 £5,263 £5,777
    Wales £4,336 £4,848 £5,223
    Average £4,590 £5,213 £5,638

     All costs exclude VAT.

     

    Here’s what the data shows for removing a chimney breast:

     

    • The minimum cost is £4,336, and the maximum cost is £6,133.
    • The total average cost is £5,147.

     

    Chimney Breast Removal Elements – Inner London

    The table below shows the cost of the associated tasks with removing a chimney breast, for Inner London:

     

     Task  Specifications  Cost
     Preliminaries £2,238
    Skip 8 yard skip £384
    Materials lift Geni SLA15 363kg £281
    Timber hoarding OSB hoarding, built-in door, timber lock £857
     Acrow propping (650mm spacing) Supply and install temporary propping £716
     Demolitions £859
    Strip out chimney breast – 1 storey £859
     Steel and structural supports £2,253
    Allowance for steel connections Allowance for steel connections £256
    Manual handling allowance for steels £366
    Steel baseplate Steel baseplate £146
    Steel beam 203x203x46 UC £540
    Steel column x2 203x203x46 UC £946
     External wall structure and lining £126
    Make good walls after demolition works Allowance to make good existing walls £126
     Ceiling structure and lining £244
    Timber ceiling structure 50×150 C24 joists @400 £163
    Make good ceilings after demolition works Make good existing ceilings £41
    Single plasterboard to ceiling 12.5mm standard gyproc plasterboard £40
     Ceiling preparation and finishes £38
    Skim to ceiling 3mm Gypsum Thistle multi-finish £38
     Wall preparation and finishes £113
    Skim to walls 3mm Gypsum Thistle multi-finish £113
     Total Cost £5,871

     

    Average Cost Of Removing Chimney Breast & Stack

    So, what’s the average cost of removing a chimney breast and chimney stack in the UK? Based on the examples covered in this article, it costs on average (when using a mid-benchmark contractor):

    • Removal of chimney stack and roof repair (external): £4,253.
    • Ground-floor chimney breast removal – single storey (internal): £5,213.

    These figures highlight just how much the total cost can vary depending on your property type and project scope. One additional factor to consider is professional cleaning, especially inside the property. If the chimney breast removal was messy and involved old soot, a professional clean can eliminate lingering odours and improve air quality.
     

    Start your free trial with BuildPartner to get a bespoke estimate of your construction project within minutes.

     
    Please remember that all costs exclude VAT.

     

    Frequently Asked Questions About Chimney Deconstruction

    Explore answers to frequently asked questions about removing chimney breasts and chimney stacks.
     

    Can I remove just the chimney breast or just the stack?

    Some people remove just the stack (above the roof) for safety or leaks, while others remove the breast to gain internal space. Both can be done separately or together.

    Will removing a chimney breast affect property value?

    Removing a chimney can free up valuable floor space, especially in smaller homes, which many buyers see as a positive. However, if the chimney is connected to a functioning fireplace—particularly in older or Victorian properties—its removal might be seen as a drawback. With the rising cost of fuel, log burners and solid fuel stoves have become very popular again.

    Will I need to clean after chimney breast removal?

    Chimney breast removal creates a lot of dust and soot. Even with dust sheets and coverings in place, there’s still a risk that dust and soot will spread to other areas of the property. Stubborn soot particles can settle deep into carpets and upholstery, so it’s best to get the professionals in.

    What’s the difference between a chimney breast and a chimney stack?

    The chimney breast is the part inside the house (often protruding into rooms), while the chimney stack is the external section that sits above the roof.

    Do I need to consult the neighbours before removing a chimney breast or stack?

    If the chimney breast or stack is part of a party wall, you’ll need to serve notice under the Party Wall Act and may need their written consent. This notice must be given at least two months before the planned work begins.