How much does it cost to build a house?

Well, often considerably less than it costs to buy a ready-made one, so you may be on to a very good thing. In fact, according to this article by you could stand to make a 30% profit. (But why would you want to sell anyway? You would be the proud owner of your dream home!) However, before even thinking about embarking on a custom-build project, it’s obviously helpful to get some idea of building cost. So, we are here to help…


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 2017 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.)


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: New build in Henley

New build costs

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.



Case study 2: 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 3: 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

** Salmen Road has been accepted as part of Open House this year (2017), and so Hugh and his team will be running tours of the house on the 16th and 17th of September. Anyone interested would be welcome to visit in person on those days and discuss the project with them. **

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.



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.


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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