Main image Allister, an architect on Design for Me (see below for more) – See his profile here and shortlist him for your project


Build cost of a house per square metre

We know how important it is to have a rough estimate of the cost at a very early stage. The easy answer for us is to say that it depends on ‘a number of factors’, which of course it does: the design, materials, the existing site conditions, where you are in the country etc. can ALL affect the cost dramatically. So, the figures in this article should be taken with a big pinch of salt and the best way of estimating your project cost is to get professional advice from an architect and/or QS who can put together a budget estimate for your particular site and brief. Spon’s Architects’ and Builders’ Price Book gives an average building cost of:

£1,375 to £1,725 per M2 for privately developed single detached houses

(Note that VAT and professional fees should be added to this.)

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Custom build case studies & their final costs per square metre

Having a building cost per square metre is only helpful as a very rough starting point, and it’s never too early in the process to speak to potential architects about your ambitions and what might be achievable for your budget (scroll to the end of the article for guidance re. finding the right kind of architect for a domestic project like this). For now though, we hope you’ll find it useful to see some case studies of custom-build house projects and their final costs.

We asked our community of architects on Design for Me to share their finished projects with us to help you get a better understanding of what you could achieve for your budget.



Case study 1: Three-bed in Tooting Bec

Project by David, an architect on Design for Me – See his profile here and shortlist him for your project

Project description

The scheme is situated in a gap site close to a high street, presenting challenging overlooking and overshadowing issues with neighbouring residents. The resolution is sensitive and creatively addresses these issues, which was praised by Wandsworth council when taken to planning committee due to planning objections.

Location: London

Construction cost  

£250,000 (£2475 per square metre)


Find out how long this self-build took to build in our article here: How long does it take to build a house?



Case study 2: Canal-side new build 

Project by Suzanne, an architect on Design for Me – See her profile here and shortlist her for your project

Project description

Open plan, four bedroom, energy efficient house with an industrial aesthetic. The plot is close to a canal and on the edge of a conservation area. The floor area for the scheme was approximately 200 square metres but the house appears to be much bigger due to the use of vaulted ceilings and high-level glazing. 

Location: North Yorkshire

Level of finish

Mid-high end finish

Construction costs

350,000 (£1,750 per square metre)

Any particular cost-saving strategies used in the design?

The staircase design was a feature we were very pleased with.

The simplicity was the use of colour, intended to compliment the glazing, and create a linear treatment that could be used on the landing balustrade which created a really considered element of the build.

The client wanted a modern design and the use of timber off the shelf components allowed for the flooring from the ground floor, to be used on the stair treads, with the risers being painted to match the balustrade, without the costs of a feature staircase.

Find out how long this self-build took to build in our article here: How long does it take to build a house?

Photos by Paul Godbehere


Case study 3: New build in Henley

Project by James, an architect on Design for Me – See his profile here and shortlist him for your project

Project description

New build replacement dwelling in Henley.

Project size

363 square metres

Construction costs

£615,000 (No VAT as new build – see note on this at the end of the article)

roughly £1,694 per square metre (Excluding professional fees)

Level of finish


Any particular cost-saving strategies used in the design?

Costs were a crucial issue for this project and therefore we adopted a contemporary approach but used traditional materials: building the walls all in blockwork and applying a render finish and weatherboarding was a very cost effective method of construction. We also designed the open plan spaces to the limit of what timber floor and roof joists could span, so the house uses very little steel. Simple things – such as having a straight flight staircase and simple bathroom designs –  kept the costs manageable for what it is quite a large new build house.

Find out how long this self-build took to build in our article here: How long does it take to build a house?












Case study 4: Near zero-carbon dwelling near Oxford

self build costs

cost to build a house

Images by Martin Gardner Photography

Project by Allister, an architect on Design for Me – See his profile here and shortlist him for your project

Project description

New sustainable dwelling to replace a 1960s bungalow in a rural area in Oxfordshire. The brief called for the house to be adaptable to the client’s future needs late into retirement. The clients have left behind comfortable, but dark and draughty, thatched stone cottages to truly embrace their sustainable, modern and light-filled home.

Project size

297 square metres

Construction costs

£750,000 in total. This figure also included re-landscaping to the vicinity of the dwelling.

roughly £2,525 per square metre (excluding professional fees and VAT on the build was re-claimed as it was a new house – see below for more information on VAT and new builds)

Level of finish

Medium – High

Any notable factors that increased costs?

Significant project specific costs relate to the sustainable measures introduced. I would estimate that these added an additional £75,000 to the build cost and included GSHP, MVHR, 36Kw (large) Solar PV array, rainwater harvesting and Tesla Powerwall. A lighting designer was engaged for the project and my clients didn’t skimp on the light fittings!


Case study 5: New build in Plaistow, London, E13

House built in garden


Project by Hugh, an architect on Design for Me – See his profile here and shortlist him for your project

Project description

A new-build semi-detached two storey house, made of textured render with terrazzo details. Inside are three bedrooms, three bathrooms and an open plan kitchen, dining and living room. These contain generous vertical spaces, such as double height bedrooms, exposed beam ceilings and a triple height staircase, on what is a constrained corner site. The site was previously a garden, and the design makes use of its end of terrace position with windows on all sides.

Project size

87 square metres 

roughly £2,299 per square metre (excluding VAT and professional fees)

Construction costs

£200,000 excluding VAT

Level of finish

Good value finish, with items that are the best quality and longest lifespan for the lowest price. For example, the windows are timber framed with aluminium cladding, so that they are hard wearing and long lasting, but from a manufacturer known for pricing very competitively.

Any notable factors that increased costs?

The corner plot meant that the building has a large perimeter, with lots of angles. This pushed up the cost of basic items, like the wall construction. That said, this pushed us to develop a really efficient wall construction, using a single skin of large format concrete blocks to make sure the walls could be built as quickly as possible. The entire construction process has taken just over 4 months.

Any particular cost-saving strategies used in the design?

We worked really hard to make the most of the space, for example, we removed the attic space to give all of the rooms on the first floor a double height ceiling, and the staircase a triple height space! In other areas, we whittled down the structure of the roof, the thickness of the walls, and the length of steelwork so that we were able to make the parts of the building you never see as efficiently as possible, while spending money on good quality external materials, insulation and windows.


Getting accurate quotes for a self-build

Architectural designer Sam gives his advice on obtaining accurate costings prior to starting your self-build.

“Whilst square metre rates can help provide big handful ‘guesstimates’ a client must appreciate every project is different and provides its own different challenges that inevitably lead to cost.

The important thing for me is that the project is firstly designed well and to an initial ball park budget set by the client. Secondly it is crucial to have a detailed written specification tender document. The reasons are that it drives the client to think through their specifics and design choices and set budgets within for ‘big purchase’ items. A detailed cost can then be provided for the project and contractual management of the finances is much more transparent and better managed through the construction phase (less chance for ‘extras’).

I think any client serious about a self build needs to get to a design stage pre-planing where they are happy with what they want to produce and then pay for it to be professionally costed prior to submitting for planning approval with ’the dream home they can’t afford’”

See Sam’s profile here and shortlist him for your project


VAT on new builds

The above figures do not include VAT.  However, your new build may be zero rated for VAT if it complies with the rules below. The following is taken from the website and further information can be found there: To qualify for a VAT refund on building projects and materials your new house must be:

  • separate and self-contained
  • for you or your family to live or holiday in
  • not be for business purposes (you can use one room as a work from home office)

If it is a conversion project, a VAT refund my only apply if it’s being converted from a non-residential building or is a residential building that has not been lived in for the past 10 years.


Controlling your budget

Getting professional advice is the best way to manage your budget. A good architect will work with you to make sure you are spending your budget in an informed way and advise where costs would be unnecessary or could be minimised. For larger or more ambitious houses, you may benefit from using a quantity surveyor too.

Make sure you get three to five quotes from recommended builders (your architect can help compile a tender list for you) to get a firm idea of the costs before starting work.


Shop around

It really pays to be picky when specifying finishes and fittings. Your builder should be able to access trade discounts. Alternatively, if you are planning on undertaking some of the work yourselves Building Supplies Online is a really good website offering trade prices to consumers. Definitely worth checking out for things like tiling, floor finishes, bathroom and kitchen fittings.


What is ‘Design for Me’?

Design for Me is a free platform to help you quickly find the right design professional for your home project. As a residential architect myself, I started Design for Me after finding that talented and innovative small firms and individuals, who are perfectly placed to design new homes, extensions and/or renovations, can often get buried under the online profiles of large commercial companies.

Before Design for Me, the right architect was very difficult to find!

Once you register your project, we’ll match it with 100s of top architects or architectural technicians, and you can see who may be available and eager to work on your project straight away.


Emily  Design for Me



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