How much does it cost to build a house in London?
Topics: architects, construction
Estimated reading time: 10 minutes
Author: Becky Wootton, Architect BArch (Hons) DipArch
ARB registration no. 085383F
Becky is an associate at Architecture for London and she also leads our construction teams. She has direct oversight of site progress, ensuring design quality and low-energy strategies are carried through to each completed home.
Contact me: 020 3951 9790
Introduction
Although there is no simple formula to work out the cost to build a house in London, estimated ranges can be used. There are, of course, many variables to consider when estimating costs.
Generally, for a new build, architect-designed home in London or the South East, a minimum construction cost might be in the region of £2,500 per square metre (£230 per square foot), plus land acquisition and professional fees. Therefore, a typical four-bedroom detached house of 160 square metres could cost a minimum of about £400,000 to build.
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Why might a new home cost more?
If the following issues are relevant to your project, then it is likely that costs will be higher. Typically, for new build homes in London, several of the below apply, and therefore a minimum of £2,800 per square metre may be a more realistic estimate:
Constrained sites
Are there party wall or site organisation issues? These can make the project more difficult for a builder.
Difficult site access
Is the site to the rear of a terrace, or accessed by a narrow track or mews street?
Our new build house with a retained facade in Primrose HillParking
Are expensive permits required to park vehicles or skips outside?
Foundations
Are specialist foundations, such as mini piles, required to reach stable ground? Is underpinning required for the neighbour’s foundations?
Superstructure
Simple block and brick cavity walls are cost-effective because London builders tend to be familiar with them, although they are slow to build. Non-standard forms of construction will often attract a premium. Cross-laminated timber, for example, has many advantages in terms of environmental impact and construction speed, yet it can still increase total costs by around 10% for a new home.
Postcode pricing
A competitive tender situation seeks to provide the best value for the client, yet contractors may still price higher in certain boroughs.
Glazing
Large glazed areas will cost significantly more than a standard wall construction with more typical windows.
Kitchen specification
Is a brand-name kitchen required? £50k or more for a brand-name kitchen may not be a worthwhile cost. £15k might well be sufficient for a kitchen with standard carcasses and good external finishes.
Our proposed new build house in SuffolkCost to build a house: additional considerations
If the highest quality finishes are required, the cost to build a house in London can reach £4,000+ per square metre (£370 per square foot). The addition of basements will increase the rates still, from around £6,000 per square metre for basement works.
It should be noted that all square metre rates given are for construction only. The following items are additional costs to consider in the build process:
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Buying costs
These will include solicitors’ fees, survey fees and Stamp Duty Land Tax.
Finance costs
Finance costs will vary depending on the amount of loan required and the loan as a percentage of the total build cost. If you have a large cash sum to contribute, you will be able to take advantage of lower borrowing rates. If you require 100% borrowing for both the land and the build costs, then the number of lenders is restricted, and interest rates will be higher. 100% loans are typically released in stages when required, with only the sum needed to buy the site released initially.
Consultants fees
Fees for all consultants will vary depending on the size and complexity of the project. Remember to allow for an architect, structural engineer, services consultant, approved inspector and a party wall surveyor.
Site purchase cost
This varies considerably depending on the size and location of the plot. The other key variable is its planning status. A plot with consent for a house will be more expensive than the same plot without approval. There is, of course significant risk involved in buying without planning consent, but the uplift in value can be considerable.
A ‘subject to planning’ offer may be beneficial for both parties, as it helps to reduce the buyer’s risk. This also ensures that the vendor achieves a good price for the land.
Our new build house on a woodland site in EssexTax benefits for new build houses:
Stamp duty
Buying a plot of land usually results in a stamp duty saving when compared with buying an existing home. The stamp duty will be calculated on the value of the land only. This is typically much less than the value of land with a house already on it. If the new build house is going to be a second property, then the potential savings are larger. This is due to the higher SDLT rates applied to second properties.
CIL
Whilst Community Infrastructure Levies can be considerable in London, self-builders are usually exempt. Individuals claiming the exemption must ‘own the property and occupy it as their principal residence for a minimum of 3 years after the work is completed’.
Planning Contributions
These vary considerably, but in London, many Local Authorities require financial contributions to help them build affordable housing elsewhere in the borough. Generally, in outer areas, these do not apply, with central zones having the highest costs.
VAT
VAT is not payable on the construction costs of a new build house (see gov.uk for full details). For work to be zero-rated, it must qualify as a “genuinely new, self-contained house or flat”. Please note that VAT will still apply to consultants’ fees.
CGT
Assuming that the house will be your principal private residence, generally, there is no capital gains tax to pay if you make a profit when you sell a new build house.
Our proposed new build house in SuffolkIs it possible to make a profit?
In London and the South East, many people want to build their own ‘Grand Designs’ house. Land is therefore scarce, and plots for individual houses can command high premiums. The cost to build a house can even be less of an issue than the cost of buying land.
It should be possible to realise a profit from building a house. The margins as a percentage of the overall costs may, however, be smaller in London.
The main driver for building a house is usually to create a home tailored to individual requirements. The Victorian terraced house just doesn’t work for all families!
Our new build house with a retained facade in Primrose HillAre energy-efficient homes more expensive?
Yes, low-energy homes are normally more expensive to build. Based on research from the Rocky Mountain Institute, the cost to build a low-energy house is typically around 5% more, but this is less than most people assume.
It is more straightforward to build a new house to a high standard (such as Passivhaus) than it is to retrofit an existing home. A new house presents an excellent opportunity to create highly insulated and draft-free spaces. The environmental and comfort benefits are rewarding, not to mention dramatically reduced energy bills, so there is a real value in budgeting for low-energy upgrades in your home design.
Having a good EPC (Energy Performance Certificate) rating for your home can also add value if you plan to sell the property in future.
Recent increases in construction costs
Construction costs increased significantly in 2020 and 2021, as COVID-19 caused significant labour and materials supply issues. Since this date, costs have increased at a steadier pace, but still at rates above inflation. As of 2026, construction costs have continued to remain high, and we haven’t yet seen a drop in prices, as some people expected.
A worked example: Essex House
This project shown here is a 130 square metre, new build, 3-bedroom house in Essex. Cost considerations were as follows:
Cost effective items
- Site: a large site with free parking and enough space for storage and efficient construction.
- Superstructure: cost-effective blockwork throughout.
- Finishing specification: this was cost-effective using brands like Duravit and Havwoods.
- Kitchen: also cost-effective with IKEA carcasses and bespoke sprayed MDF doors.
Additional expense items
- Special foundations: due to the proximity of protected trees, mini piles were required to avoid damaging roots.
- Glazing: large areas of glazing, including full-height sliding doors to the garden.
- Timber cladding: timber rainscreen cladding is an addition to standard block construction.
- Additional luxuries: a tiled terrazzo floor and work surfaces.
- Landscaping: a large pond.
Bearing in mind the above, the project cost today would likely be around £3,000 per square metre.
Further reading on the Journal:
House build costs FAQ
Generally, for a new build, architect-designed home in London or the South East, a minimum construction cost might be in the region of £2,250 per square metre. Prices can, however, reach £4,000+ per square metre if the highest quality finishes are required and basements are added.
VAT is not payable on the construction costs of a new build house. For work to be zero-rated, it must qualify as a “genuinely new, self-contained house or flat”. Please note that VAT will still apply to consultants’ fees.
In London and the South East, many people want to build their own ‘grand designs’. Land is therefore scarce, and plots for individual houses can command high premiums. Whilst it should be possible to realise a profit from building a house, the margins as a percentage of the overall costs may be smaller in London.
In addition to the build costs, the following also need to be budgeted for. Land costs, buying costs (legal fees, SDLT, etc.), finance costs and design consultants’ fees.