When it comes to working out how much it costs to build a house, the answer is ‘how long is a piece of string?’. There are endless factors at play; where you are in the UK, the size of your intended house, the materials you plan to use, the quality of finishing and fittings throughout and so much more. There is a general estimation that building a house in 2024 in the UK costs £650 to £2,250 per square metre, but that can be entirely off the mark for many self builders and varies on that scale depending on how much DIY versus professional lift you are using. There's also location to take into consideration, as costs in London and the south east far outweigh other areas of the UK.
What costs are associated with building a house?
Below is a general overview of the many places you need to apportion budget when undertaking a new build, and some cost significantly more than others. These run from the most costly to the least, though of course this can change project to project. However, the structure – that is to say, all external walls, cladding (insulation and windows) and the roofing – will typically always be the largest cost and can be estimated to be between 25-30% of a budget. The cost of a plot of land depends entirely on the geographical location of your intended build. For example, a plot in the centre of Mayfair will cost a lot more than a field in the north of England. Generally, be prepared to spend more in urban areas than rural locations and be prepared that it could cost the same amount of money as the build itself.
- The plot
- The structure
- Foundations and groundworks
- Joinery, including kitchen and staircases
- Plumbing and heating
- Landscaping
- Plastering
- Drainage
- Flooring
- Electrics
- Decoration
- Tiling
The biggest costs come at the start of the build and the smaller ones are mostly internal so there is always a way to rebalance the budget towards the latter stages if the cost of laying the foundations, for example, ends up going over what you had expected. It always pays to expect the unexpected when building a house and Robert Cox, Director of Adam Architecture advises keeping back a slush fund of at least 10% of your budget as contingency.
A case study
In the construction industry, the saying ‘a third, a third, a third’ comes up a lot. What it means is that you should expect to spend a third on the plot, a third on the build and make a third again in profit, if and when you come to sell your build. A current project being worked on by Architecture for London breaks it down rather neatly; the proposed house is a Passivhaus in Muswell Hill, made from timber, textured lime plaster and natural stone. The plot of land is for sale with The Modern House for £550,000 and comes with planning permission in place for Architecture for London’s design. The cost estimate for the house has been drawn up and comes to £563,138 in total (not including contingencies at this stage, or the £60,000 architect's fees). That brings the total estimated cost to £1,113,138 but the estimated value of the house once built is currently £1.5million.
Here is how that £563,138 is broken down:
- Protection, demolitions and alterations: £41,000, this includes excavations and underpinning for the groundworks – 7% of total cost
- Foundations, slab and structure: £93,400, includes all foundations laid, retaining and load bearing walls constructed and support beams – 16.5% of total cost
- External walls: £28,700 – 5% of total cost
- Roof: £61,500, including £9,000 for a green roof – 11% of total cost
- Insulation, damp and waterproofing: £27,000 – 4.8% of total cost
- Windows and external doors: £66,800 – 11.8% of total cost
- Internal partitions: £20,008 – 3.6% of total cost
- Internal doors: £5,060 – 0.9% of total cost
- Staircase: £8,000 – 1.4% of total cost
- Joinery: £12,520, including kitchen joinery and utility room – 2.2% of total cost
- Finishes: £70,300, including £25,000 for engineered timber flooring throughout, all plastering and plasterboard – 12.4% of total cost
- Services: £61,750, including all bathroom sanitaryware, plumbing, heating and electricals – 11% of total cost
- Fixtures and fittings: £700 – 0.1% of total cost
- External works: £30,000, this includes all landscaping work, paving and stairs – 5.3% of total cost
- Preliminaries: £36,400, this includes all skips, lorries, insurance and site management – 6.5% of total cost
The cost of materials
A key factor in what the house will end up costing comes down to the materials used, and they vary in price (and have unfortunately skyrocketed since the pandemic). Building a house from bricks and block work is the most cost effective way, followed by a timber frame. SIPS (Structural Insulated Panel Systems) and Insulated Concrete Formwork (ICF) are the two most expensive methods of building. SIPS are very high performance and very easy to work with; they consist of two layers of oriented strand board (a material similar to particle board) with a thick, insulated core in the middle. The benefit is that they are energy-efficient and so will make running a house cheaper in the long run with lower energy costs. They are also more sustainable and a structure can be put up using SIPS in a matter of days compared to the lengthy process of building with bricks and mortar. Similarly, ICF is fast to work with, energy efficient and generally better than older methods. Hollow blocks of insulating material arrive on site to the building’s specification; these are then laid out in the framework and concrete is poured in the gap between them. The added benefit over SIPS is that you have two layers of insulation wrapping the structure of the building, making it even more energy efficient.
It’s not as simple as bricks and mortar being the cheapest, because it costs a lot more in building time – and time is money when you’re paying workers – and it’ll cost a lot more in energy efficiency over the years. Of course, it all depends on what you can afford at the time of building but there is a lot to be said for a higher upfront cost that is then paid off down the years. “Spending money upfront on high quality, traditional materials, good and well considered architectural design along with other design and construction professionals leads to a payback overtime," confirms Robert. "The more you invest at the start will pay dividends in the future, as the starting blocks of projects are items you cannot change without substantial consequences.”
The design team
A key factor in building a house is the team, and as with building material costs, it can pay to pay a little more. Once an architect has drawn up your plans, you then need to send them to a quantity surveyor, who will cost up every single item needed in the house, even bolts and screws – this is called a Bill of Quantities. Some choose to skip the next stage but it is key in keeping costs on track as far as possible: sending the Bill of Quantities to a handful of contractors. The contractors will come back with their cost for the project and a schedule of how long it will take, which can then be converted into a contract (it's worth noting that estimated project costs between contractors can vary quite dramatically). The contractor is then responsible for employing all individual parties to undertake each part of the project, from groundworks to final detailing and tiling, and they can be held accountable if a project goes over budget. It’s an added cost at the start but it can lead to far less surprises along the way.
For Robert, there's another key role: a VAT specialist. “They can advise homeowners on the nuances surrounding VAT in construction," he explains, “which is particularly prevalent on multi-phased and complex projects. Historically, construction works to listed buildings command VAT, but new builds are VAT exempt. This is a complex and intricate area and can become even more complex if the project contains new and existing elements. The appointment of a VAT specialist early in the design process, along with a cost consultant (Quantity Surveyor) can help clients truly understand the costs involved and where liabilities can arise.”
The takeaway
There is no hard and fast rule as to how much it costs to build a house and even the national averages per square metre are hard to abide by. What we can glean however – and you need only watch an episode or two of Grand Designs to know this – is that it is likely to cost more and take longer than any initial plans. However, with the right team, the right apportioning of the budget and enough of a slush fund, it pays dividends. What with the housing market being as it currently is, building your own home seems more and more attractive by the day.
