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):

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

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):

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):

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

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):

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

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.

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:

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.

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:

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:

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.

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):

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):

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 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.

July 28^th, 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:

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):

 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.

 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.

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:

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:

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:

 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:

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.

June 28^th, 2025

Underfloor heating is gaining popularity in UK homes due to its energy efficiency and the rising cost of heating bills. It can be up to 25% more efficient than traditional central heating systems with radiators, and up to 40% more efficient when combined with a heat pump. Conservative estimates suggest you could save up to £145 per year.

But how much does it cost to install underfloor heating? In this guide, we’ll break down the installation costs of underfloor heating in the UK for 2025, so you can weigh up the cost benefit versus the potential savings.

Before we begin, it’s important to draw a distinction between the two main types of underfloor heating: wet (water-based) and electric.

• Wet underfloor heating – pipework connected to your central heating and boiler, usually installed by a qualified plumber or heating engineer.
• Electric underfloor heating – uses electric mats or cables, installed and certified by a qualified electrician.

The complexity of installation depends on factors like the type of system, whether it’s a new build or retrofit, the floor construction, and the size of the area.

Additional Factors To Consider For Underfloor Heating Installs

When retrofitting underfloor heating, particularly wet systems, homeowners often underestimate the full cost. It’s not just about laying pipes or cables; the process often involves removing old radiators, capping off plumbing, repairing wall damage, fitting new flooring, and replacing skirting boards and architraves.

For new builds, the process is more straightforward; no demolitions or making good, just the cost of supplying and fitting the system into a new space.

Electric underfloor heating is also popular in upstairs bathrooms, where its thinner profile makes it easier to install without raising floor levels. It usually doesn’t require disturbing existing wall finishes.

Underfloor Heating Conversion 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 cost of installing underfloor heating 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 both your budget and the level of finish you’re aiming for.

Cost Of Installing Wet Underfloor Heating - Retrofit

The table below shows the average cost of retrofitting wet underfloor heating for a 50m² layout (i.e., ground floor):

All costs exclude VAT.        

Here’s what the data shows for retrofitting underfloor heating across a 50m² ground-floor layout:

• It costs 7% more to install underfloor heating in Inner London.
• The minimum cost is £13,627, and the maximum cost is £18,840.
• The total average cost is £15,878, or £308 per square metre.

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

Cost Of Installing Wet Underfloor Heating - Newbuild

The table below shows the average cost of installing wet underfloor heating in a newbuild home, with a 50m² layout:

 All costs exclude VAT.

Here’s what the data shows for installing underfloor heating in a newbuild:

• The minimum cost is £4,651, and the maximum cost is £6,495.
• The total average cost is £5,459, or £106 per square metre.

Cost Of Installing Electric Underfloor Heating - Bathroom

The table below shows the average cost of installing electric underfloor heating in a 9m² bathroom; these costs only include the cost of the heating installation and do not include other elements such as new flooring and making good wall finishes:

 All costs exclude VAT.

Here’s what the data shows for retrofitting electric underfloor heating in an existing bathroom:

• The minimum cost is £626, and the maximum cost is £862.
• The total average cost is £732, or £81 per square metre.

Average Cost Of Installing Underfloor Heating

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

• Wet underfloor heating - retrofit ground floor: £16,138, or £313 per square metre.
• Wet underfloor heating - newbuild ground floor: £5,552, or £108 per square metre.
• Electric underfloor heating - main bathroom (retrofit): £732, or £81 per square metre.

These figures highlight just how much the total cost can vary depending on your project type and scope.

A common assumption is that electric systems are cheaper, but while that may be true for small areas with minimal disruption, in some cases, there’s price parity with wet systems.

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 Installing Underfloor Heating

Here are some answers to frequently asked questions about installing underfloor heating.

What’s the difference between electric and wet underfloor heating?

Wet systems use hot water pumped through pipes and are cheaper to run but more complex to install. Electric systems use heated cables or mats, are easier to install, but cost more to run.

What's the best type of flooring to use with underfloor heating?

The best flooring for underfloor heating is one that conducts heat well and is stable with temperature changes. Tile and stone are great because they transfer heat efficiently and retain warmth. Engineered wood can also work well. Solid hardwood, however, can warp with changes in temperature and moisture.

Some vinyl and laminate options are suitable, but it’s always worth checking their compatibility with underfloor heating to prevent damage.

Will underfloor heating raise my floor height?

Installing underfloor heating will raise your floor height. Electric systems typically add around 15–30mm, while wet systems can add 30–70mm or more due to pipework and screed layers.

After installing, you may need to adjust or replace skirting boards and architraves to fit the new floor level, and there will often be extra work making good plaster and repainting affected walls.

Is underfloor heating expensive to run?

Electric underfloor heating typically uses 0.1–0.2 kWh per m² per hour, which costs around 3–6p per m² at current electricity rates.

Wet systems are more efficient, using about 0.05–0.1 kWh per m² per hour, and with gas at roughly 8p per kWh, the cost is closer to 0.4–0.8p per m².

That means wet underfloor heating is roughly 7 to 8 times cheaper to run than electric.

What’s the downside of underfloor heating?

With underfloor heating, you lose the option to hang clothes or towels on radiators to dry. You have no available warm surfaces for quick drying, something many of us rely on, particularly in colder months.