How Much Does It Cost to Renovate a House in London?
Last updated: July 2026
Asking how much it costs to renovate a house is a little like asking how long a journey will take without knowing the destination. The size matters, of course, but so do the route, the condition of the building and how ambitious you want to be when you arrive.
Even so, realistic early figures are useful. They help homeowners understand whether a project is feasible before too much time is spent developing plans around an unsuitable budget.
Based on the London residential projects we are currently designing, costing and taking through construction, these are the broad allowances we recommend using at the beginning of a project.
London house renovation costs at a glance
Whole-house renovation and extension:
£3,000–£3,400 per m²
Structurally intensive work:
£4,000–£4,500 per m²
Non-structural refurbishment and fit-out:
£1,800–£2,200 per m²
These figures exclude VAT.
They include a general allowance for kitchens, bathrooms, fitted joinery, finishes and landscaping. Particularly bespoke interiors, specialist materials, extensive external works or unusually complex sites can take a project beyond these ranges.
For an early estimate of the total project budget, rather than the construction cost alone, we normally recommend adding approximately 50% to the estimated construction cost. This provides a broad allowance for professional fees, permissions, investigations, contingency and VAT.
What is the difference between construction cost and total project cost?
The construction cost is the amount paid to the building contractor for carrying out the work.
A useful shorthand is to imagine turning the house upside down. Most things that remain attached would usually sit within the construction cost: walls, floors, windows, kitchen units, sanitaryware, fitted lighting, built-in joinery and finishes.
The construction cost does not represent the full amount you will spend on the project.
A total project budget also needs to account for the professional team, surveys, statutory permissions, investigations, contingency and VAT. Depending on the project, it might also include temporary accommodation, furniture and other client-supplied items.
Confusing the construction cost with the total project budget is one of the most common causes of unrealistic early expectations.
How to estimate a London renovation cost per square metre
A cost per square metre is useful during the early stages of a project because detailed drawings do not yet exist. It allows you to test the broad relationship between the size of the proposed work and the available budget.
For a substantial London project combining an extension with the refurbishment of the existing house, we currently recommend allowing approximately £3,000–£3,400 per m², excluding VAT.
This is a blended whole-house rate. It combines expensive areas, such as a new structural extension, kitchen and bathrooms, with less intensive work to existing bedrooms, hallways and living rooms.
It should not be confused with the rate for constructing an extension in isolation.
New structural work can cost considerably more per square metre because it may involve demolition, foundations, drainage, steelwork, external walls, roofing, glazing and new building services. The structurally intensive parts of a project are currently more likely to fall within the range of £4,000–£4,500 per m².
The lower blended rate works because not every square metre of an existing house receives the same level of intervention.
Refurbishment cost versus structural renovation cost
Two projects of the same overall size can have very different budgets.
A house being redecorated, rewired and fitted with a new kitchen involves a different level of work from one being excavated, extended and structurally reorganised.
For this reason, it is often helpful to divide a project into two broad categories.
Structurally intensive work
Allow approximately £4,000–£4,500 per m² for areas involving substantial new construction or structural alteration.
This might include:
New rear or side extensions / Significant structural openings / Lowering floors / New foundations and drainage / Major roof alterations / Extensive new glazing / Complex steelwork
Non-structural refurbishment and fit-out
Allow approximately £1,800–£2,200 per m² for existing parts of the house receiving primarily internal refurbishment.
This might include:
New floor and wall finishes / Internal partitions and doors / Kitchen and bathroom replacement / Electrical and plumbing upgrades / Fitted joinery / Decoration and lighting
Most whole-house projects include a mixture of both. That is why a single rate applied indiscriminately to every part of the property can be misleading.
A worked example: whole-house renovation and extension
Consider an existing London house of 120m² with a proposed 20m² extension.
The completed house would have a total area of approximately 140m².
Using the blended whole-house rate:
140m² × £3,000–£3,400 per m²
Estimated construction cost:
£420,000–£476,000 excluding VAT
Adding approximately 50% for professional fees, permissions, contingency and VAT gives an early total project allowance of:
Approximately £630,000–£714,000
This is a feasibility estimate, not a quotation. It gives the design team and homeowner a realistic starting point from which the scope and priorities can be developed.
A worked example: refurbishment without an extension
Now consider an existing house of 120m² receiving a substantial internal refurbishment but no major structural extension.
Using the non-structural refurbishment rate:
120m² × £1,800–£2,200 per m²
Estimated construction cost:
£216,000–£264,000 excluding VAT
Adding approximately 50% gives an early total project allowance of:
Approximately £324,000–£396,000
The final figure would depend on how much of the house is being refurbished and the level of specification. A project involving several new bathrooms, extensive joinery or a highly bespoke kitchen may sit towards the upper end or move beyond it.
What should be added to the construction cost?
Professional fees and permissions
For a substantial renovation, we recommend allowing approximately 15–20% of the construction cost for the full professional team.
This may include the architect, structural engineer, cost consultant, measured surveyor, building control adviser and other specialist consultants.
The precise percentage depends on the complexity of the property, the extent of the service and the number of specialists required. A listed building, basement project or technically ambitious low-energy retrofit may require more consultant input than a straightforward refurbishment.
Application fees and permissions are usually a relatively small part of the total budget, but they should still be included. Surveys, trial pits and other investigations also need to be considered.
Contingency
For most renovation projects, we recommend a contingency of approximately 10% of the construction cost.
For a Listed Building, we would normally increase this to approximately 15%.
Existing buildings contain uncertainty. Opening a wall, lifting a floor or exposing a roof can reveal conditions that could not have been fully understood from surveys alone.
A contingency is not spare money waiting to be spent. It is protection against the unknowns that naturally come with altering an existing building.
VAT
The construction rates in this guide exclude VAT.
VAT should therefore be included when moving from a construction estimate to a total project budget. The precise treatment can depend on the work and the services being supplied, so project-specific advice should be obtained where reduced or alternative rates might apply.
Why do period-property renovation costs vary so much?
London’s period homes often share familiar characteristics, but no two renovation projects are quite the same.
The condition of the existing building has a significant influence. A house that has been maintained carefully may need relatively predictable work. One with failing roofs, damp, outdated wiring or poorly constructed previous alterations may require substantial remedial work before the visible improvements begin.
Access also matters. Restricted streets, limited storage and difficult routes through an occupied terrace can all affect labour and preliminaries.
Structural ambition is another major factor. A modest opening between two rooms is very different from removing large sections of the rear wall, lowering a floor or creating a basement.
Listed Buildings and homes in Conservation Areas can require more investigation, specialist input and carefully selected materials. The objective is not simply to spend more, but to make interventions that are appropriate to the building and likely to last.
Environmental improvements can also alter the initial budget. Insulation, high-performance glazing, airtightness, heat pumps, solar panels and ventilation systems involve capital expenditure, but they may improve comfort, reduce energy demand and make the house more resilient over the long term.
Kitchens, bathrooms and fitted joinery
The figures in this guide include general allowances for kitchens, bathrooms and fitted joinery.
These are also among the areas where costs can vary most.
A kitchen assembled from good-quality standard components with carefully designed bespoke details may offer excellent value. A fully bespoke kitchen using specialist materials and complex fabrication will cost considerably more.
The same applies to bathrooms, wardrobes, shelving and other fitted elements. Thoughtful design is not necessarily about selecting the most expensive option. It is about deciding where bespoke work will make a meaningful difference and where standard products can be used intelligently.
Landscaping and external works
Our figures include a general allowance for associated landscaping and external work.
Large retaining walls, extensive level changes, mature planting, specialist paving, garden buildings or significant drainage work may require a separate and more detailed allowance.
Gardens are sometimes treated as something that can be resolved at the end. In practice, levels, thresholds, drainage and planting are closely connected to the architecture and should be considered early.
How reliable is a renovation cost per square metre?
A square-metre rate is useful for feasibility, but it is not a substitute for costing a developed design.
The rate cannot fully account for the condition of the existing building, the amount of structural work, the specification or the practical constraints of the site.
Once an initial design has been developed, we usually recommend appointing an independent cost consultant to prepare a more detailed estimate.
This changes the conversation. Rather than discussing whether the project is broadly affordable, the client and design team can see where the money is being spent and make informed choices.
Some decisions may reduce cost without compromising the central idea. Others may be worth protecting because they have a disproportionate effect on how the house feels and works.
Good cost management is not simply a process of removing things. It is about understanding priorities.
How BVDS manages renovation costs
We begin discussing cost from the first design meeting.
At this stage, the information is necessarily broad, but early sketches can still be tested against realistic allowances. This helps establish whether the size and ambition of the brief are aligned with the available budget.
As the preferred design develops, we recommend bringing in an independent cost consultant. On many projects, an initial cost report is prepared before the planning application is submitted.
This provides an opportunity to review the design while meaningful changes can still be made. It is far better to understand the financial implications of a proposal at this stage than after a detailed technical package has been completed.
The cost plan then remains part of the design process. Structural decisions, glazing, materials, heating, joinery and finishes can all be reviewed against the agreed priorities.
There will always be uncertainty in renovating an existing home. The aim is not to pretend otherwise, but to reduce uncertainty where possible and create enough flexibility to deal with what remains.
If you are considering renovating or extending a London home and would like to understand what may be realistic for your property and budget, please get in touch with BVDS to arrange an initial conversation.
Frequently Asked Questions
How much does it cost to renovate a house in London?
For a substantial whole-house renovation and extension, we currently recommend allowing approximately £3,000–£3,400 per m², excluding VAT. An early total project budget can be estimated by adding approximately 50% for professional fees, permissions, contingency and VAT.
What is the refurbishment cost per m² in London?
For non-structural refurbishment and fit-out within an existing house, a reasonable early allowance is approximately £1,800–£2,200 per m², excluding VAT.
How much does structurally intensive renovation work cost?
Areas involving substantial new construction or structural alteration are more likely to cost approximately £4,000–£4,500 per m², excluding VAT.
Why does an extension cost more per square metre than a whole-house renovation?
An extension requires foundations, drainage, structure, roofing, external walls and glazing. Existing rooms being refurbished may only need services, finishes and joinery. A whole-house rate averages these different types of work together.
How much should I allow for professional fees?
For a substantial London renovation, allow approximately 15–20% of the construction cost for the full professional team. The exact figure will depend on the project and the services required.
How much contingency should I include?
Allow approximately 10% of the construction cost for most renovation projects. For Listed Buildings, we generally recommend approximately 15%.
Are kitchens and bathrooms included in the cost per square metre?
Yes. The rates in this guide include a general allowance for kitchens, bathrooms, fitted joinery and landscaping. Highly bespoke or specialist elements may increase the cost.
How much does it cost to renovate a Victorian house?
The broad rates are similar, but Victorian and other period homes can carry additional costs because of their condition, historic fabric, previous alterations and the need for breathable or specialist construction. A project-specific survey and cost plan are therefore particularly valuable.
Some other links you might find useful
From Sketch to Site: What Really Happens When You Work with BVDS
Fabric First: Designing Comfortable, Low-Energy Homes
