How Much Does It Cost to Renovate a House in London?
If you’ve started researching costs, you’ve probably noticed something frustrating.
Most advice focuses on extensions.
Square metre rates. Rear additions. Side returns.
But your project is not just an extension.
It is your whole home.
And that changes everything.
Why renovation costs in London are hard to pin down
An extension is one piece of work.
A renovation is a system.
You are not just building something new. You are:
reworking how the house flows
upgrading how it performs
uncovering what is already there
making hundreds of small decisions that affect cost
That is why two projects with the same floor area can have very different budgets.
A light refurbishment is one thing.
A full transformation of a London period home is something else entirely.
Typical renovation cost ranges in London
Let’s start with something concrete.
For most architect-led, whole-house renovations in London, construction costs typically fall within the ranges below.
These figures relate to the construction cost, meaning the building work itself. They do not include professional fees, VAT, or contingency, which together form a significant part of the overall budget.
£2,000 – £3,000 per m²
A more straightforward renovation:
lighter structural changes
selective upgrades to services
simpler finishes
This suits projects where the layout largely works and the focus is on improving what is already there.
£3,000 – £4,500 per m²
A typical architect-led project:
significant layout changes
new kitchen and bathrooms
full upgrades to electrics, plumbing, and heating
improved insulation and windows
good quality materials and detailing
This is where many full-house renovations in London sit, particularly in Victorian and Edwardian homes.
£4,500 – £6,500+ per m²
A more ambitious transformation:
extensive structural work
high-quality materials
bespoke joinery
deeper energy upgrades
carefully considered detailing throughout
These projects involve a higher level of design, coordination, and finish.
What this means for your overall budget
Construction cost is only part of the picture.
In most London renovation projects, the construction cost represents around 65–80% of the total project budget, once professional fees, VAT, and contingency are included.
The remaining portion covers professional fees, VAT, and a sensible contingency allowance.
This balance varies depending on the size and complexity of the project. Smaller projects often have proportionally higher fees, while larger, whole-house renovations in London tend to sit more comfortably within these ranges.
What drives renovation cost in London
Costs vary because they are driven by decisions.
The most important ones are:
How much you change the layout
Moving walls often means structural work.
That can involve steel beams, new supports, and reworking how the house stands up.
The more you change, the more complex the build becomes.
The condition of the existing house
Older homes come with unknowns.
You may uncover:
damp or moisture issues
outdated wiring
ageing plumbing
uneven structures
These are not extras. They are part of making the house work properly.
Services and systems
Electrics, plumbing, heating, and ventilation are often underestimated.
But they are fundamental to how the house feels to live in.
A full upgrade across a whole house is a significant part of the budget.
Level of finish
There is a wide range between standard, off-the-shelf solutions and carefully designed, built-in elements.
Kitchens, joinery, flooring, and detailing all influence cost.
Energy performance
Many renovations now include improving how the house performs.
This can include:
insulation to reduce heat loss
airtightness, which means reducing unwanted drafts
better windows
ventilation systems that provide fresh air without losing heat
These upgrades are often grouped under retrofit. You can explore this further in our retrofit guidance.
Why your renovation cost is not fixed
It is easy to think of construction cost as a single number.
In reality, it is the accumulation of many smaller decisions.
how much you change the layout
how far you upgrade the building
the level of finish
the complexity of the structure
the systems you introduce
Each decision carries a cost. Together, they define the project.
The difference between a project that stays on budget and one that doesn’t is how those decisions are made and when.
Without a clear process, decisions are made in isolation and costs begin to drift.
With the right structure, they are tested and aligned early, so the budget becomes something you can understand and manage rather than react to.
Our role is to guide you through these decisions, so you can make informed choices that shape both the cost of your project and the long-term enjoyment of your home.
We explain this in more detail in our guide to how early cost planning protects your renovation budget.
Why an extension is only part of the total cost
It is very common to start with:
“How much does an extension cost in London?”
That is a useful question. But it is only part of the picture.
An extension might account for a portion of the build cost. The rest sits within the existing house.
That includes:
reworking rooms
upgrading services
improving comfort and performance
finishes throughout
If you only budget for the extension, you will underestimate the project.
If you want to understand this in more detail, you can read our guide to the cost of an extension in London.
The hidden costs in a whole-house renovation
This is where budgets tend to drift.
The existing house
You are not starting from a blank slate.
Opening up walls and floors often reveals work that needs doing to make the house safe and functional.
Services upgrades
Old electrics and plumbing rarely meet modern standards.
Upgrading them is often essential in a full renovation.
Finishes across the whole house
It is easy to focus on the main spaces.
But every room adds up:
flooring
doors
joinery
decoration
Across a whole house, this becomes a significant cost.
Coordination and detail
Clear design reduces uncertainty during construction.
Without it, projects often incur additional costs through changes and adjustments on site.
How to budget for a renovation project in London
To understand your project properly, you need to look beyond construction.
Professional fees
Professional fees are an important part of the overall budget, and they play a key role in how clearly your project is defined and managed.
We explain how this works, and what is included, in our guide to understanding architects’ fees for major home projects.
VAT
Most residential renovation work includes VAT, which has a significant impact on the total budget.
Contingency
A sensible allowance for unknowns.
Typically 10–15%, depending on how defined the project is.
A clearer way to think about renovation cost
Instead of asking:
“What is the cost per square metre?”
A more useful question is:
“What level of transformation are we aiming for, and how do we align that with our budget?”
Because that is what really drives cost.
With the right process, this becomes clear early and evolves in a controlled way as the design develops.
How to get clarity on your project
Every home is different.
The ranges above are a starting point, but what most homeowners want is clarity on their own project and how it might unfold.
If you are at an early stage, our Home Visit and Appraisal is designed to give you a realistic understanding of what is possible, the likely cost range, and how your project could be approached.
If you would like clarity on your own project, you can book a consultation.
Frequently asked questions about renovation costs in London
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Most architect-led, whole-house renovations fall between £2,000 and £6,500+ per m² for construction, depending on scope and quality.
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Around £3,000 per m² can be enough for a well-planned renovation. More complex or higher-quality projects will typically exceed this.
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Construction cost includes building work, structural changes, and finishes. It does not include professional fees, VAT, or contingency.
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Because they are driven by decisions, including layout, structure, finishes, and upgrades to the building.
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By aligning design and cost early and testing decisions as the project develops. We explain this in our guide to how early cost planning protects your renovation budget.
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No. A large portion of the budget is usually within the existing house, not just the extension.
