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How Much Does it Cost to Build a House? What to Bear in Mind in 2021

how much does it cost to build a house?
(Image credit: getty images)

In 2021, the question how much does it cost to build a house is a little bit more complicated. When it comes to a self build, there are a huge amount of variables that can affect the overall cost of your project, however, with a lack of tradespeople to meet demand driving up prices, alongside a construction material shortage, self building at the moment may come with an unexpected premium. 

Figures show that building material costs had increased around 23% year on year in August, a staggering figure that could wreak havoc across a larger build project. Unfortunately for self builders, timber and steel are in particular in short supply, leading to cost rises of as much as 74%. 

Fortunately, if you build the right house, it's still profitable to build your own home, and with no end to the price rises in site at the moment, increased costs are something to be wary of, rather than putting a halt to your build project. 

In this guide, we break down all the costs involved in building a house. Use it alongside our build cost calculator to get an estimate how much your project could cost, helping you to set a budget for your build. 

How Much Should I Spend on Building a House?

The real answer to 'how much does it cost to build a house?' is how much have you got to spend. Self build can be such a personalised experience that there is likely an option available for you no matter the budget (within reason).

Determining how much you have to spend is a case of looking at the following:

  • your savings
  • equity from the sale of your current home
  • funds available via a self build mortgage if required
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The first expense, before you even start to build your home is the plot (unless you already own one), the cost of which will depend on where you want to live. You'll need to factor in the costs related to purchasing the land, alongside legal fees and stamp duty. You can visit hmrc.gov.uk for the latest SDLT rates. 

You can also get a good idea of plot prices by visiting plotfinder.net — the UK’s largest database of small development sites. 

(MORE: How to Find a Plot)

Once you've worked out this cost, subtract it from your savings, equity and mortgage and you'll be left with your build budget. However, we suggest setting 10-15% aside as your contingency fund straight away. This can be used to cover any unforeseen circumstances that might arise, or to pay fees such as the architect, which are based on the overall build cost and tend to be between 7 and 15%.

How Should I Divide my Budget?

a breakdown of how much it costs to build a house

This pie chart provides a breakdown of the costs involved in a typical self build project (clockwise from top). (Image credit: Future)
Top Tip

Try not to change your mind during the project as this will cost both time and money. Any savings you make should be added to the contingency fund or used for finishing touches once the majority of the build is complete.

The two largest slices of the pie, as demonstrated in this pie chart, are the cost of your build's superstructure and foundations and floor structure. The superstructure includes the walling, external cladding and the roofing, and will typical account for 25 to 30% of the overall budget. The cost of the superstructure will vary depending on the size and construction system used. 

Aside from these two expenses, the rest of your build tends to account for between 5 and 10% of the total cost. The trick with balancing your budget it to understand that some individual elements can be reduced in price later down the line if earlier elements go over the initial budget.

Construction Materials Shortage

Before we get into the figures for how much it costs to build a house in 2021, bear in mind that while these are the latest figures, they may not factor in fluctuating material costs caused by the pandemic, the lorry driver shortage and Brexit. 

But how much does this equate across the entirety of your build? 

In September, a market intelligence report from Turner & Townsend found that by the end of 2021, tenders are likely to have increased by 10% from the same time last year. 

As it's unclear whether the materials shortage will continue long-term, factoring in this added cost to your budget is important, as is keeping communications open with your builder on the changes to material costs. To help reduce costs, get more involved in the material sourcing process, and get to know your supply chain so you can work more closely with them. 

Don't forget to plan ahead, as not to find yourself lacking essential materials and holding up the build from continuing. 

How Much do Different Construction System Costs?

exterior of a modern eco self build home in Wales which cost £385k

This modern self build in Wales cost its owners £785,000 to build. This didn't include the cost of the plot, which was bought for £385,000 back in 2014.  (Image credit: Jeremy Phillips)

The cost of the load bearing structure of a self build depends on the system used. However, it's important to consider that while some systems may cost more than others, you also need to take into account the speed of build, and any savings a particular system might incur further down the build. 

For example:

  • Using concrete blockwork for the external walls and ground floor partitions, with timber partitions on the first floor, the structural walls will represent approximately 13-15% of the overall build cost — an average of £30,000. 
  • Switching to a timber frame construction method with 140mm studs width won't affect the cost hugely. As an example, this may cost as little as 10% more than using blockwork, but the overall impact on the cost of the house is only 10% of 15% — around 1.5% — which could equate to only £3,000 in total. 
  • Building with oak frame is more expensive, possibly as much as 40-50% more than concrete blockwork. This will add 6-7% to the overall construction costs — an average of £15,000. 
  • Other modern methods of construction such as structural insulated panels (SIPs) and insulated concrete formwork (ICF), will be between 5% and 20% more expensive than blockwork. That adds 1–3% (or £6,000) to overall construction costs, but brings benefits in terms of faster build speed and superior levels of airtightness, without the need for applying insulation later in the build. 

(MORE: How to Choose a Construction System)

How Much do Service Connections Cost?

If your plot is not connected to mains services, allow £10,000 for connection to water, sewers, bringing electricity to site, telephone and gas. If the site does not have access to mains gas, you will need to budget an extra £2,000–£2,500 — more for renewables.

If there is no mains sewer, you will need to budget for an off-mains alternative (in place of a mains drainage connection, for which you can deduct £2,500).

As a budget figure, allow £2,500–£3,500 for a small family and £3,500-£5,500 for a larger household.

If the site is a replacement dwelling, you may save the cost of some or all service connections, but will need to set aside a similar sum for demolition and site clearance.

How Much do the Foundations Cost?

While the foundation costs per m² are likely to be the same, no matter the overall size and spec of what you're building, the soil type will dictate the foundation system for your site, which can vary and add expense to your build. 

It's something that is hard to predict until you break ground, and also generally out of your control. You don't get to make the decision on the type of foundation you use, rather a local authority surveyor from Building Control or licenced inspector will make the call on the foundation system required, 

They may suggest engineered solutions including rafts, piles and reinforced ringbeams or a reinforced slab. At a worse case scenario, this could add as much as £10,000 to your foundation cost. 

foundation choice does play a large part of how much it costs to build a house

You might not be able to confirm the type of foundations you need until you start digging. (Image credit: David Snell)

Other variables that may affect your foundation costs include:

  • Proximity of your site to the nearest ready-mix concrete plant
  • Proximity of the nearest tip for removing spoil (known as muck away)
  • The gradient of the ground you're building on 

When it comes to building on a sloping site, the general rule is that for every 5° inclination, your build costs will increase by £5,000. This is due to the work involved in creating level terraces to build, landscaping work to create retaining walls for driveways and paths, among other additional costs. 

(MORE: What you Need to Know About Foundations for Difficult Sites)

How Much do Different Exterior Finishes Cost?

How Much Does It Cost to Build a House with Brick?

Building with brick will typically cost around 5% of the house build, approximately £11,000. However, this cost depends on the type of brick used. This figure is based on stock bricks costing between £350-£1,000.

Character bricks, including reclaimed bricks, are more likely to start at around £850, effectively more than doubling the cost of this element in your build to £20,460, especially when factoring in the additional labour time required to lay irregular-shaped bricks. This is especially true if they are laid in a traditional bond such as Flemish.

Additional costs can be incurred with detailing, such as brick arches.

reclaimed bricks in a London extension

Using reclaimed bricks in your build will add to the cost per square metre.  (Image credit: Resi)

How Much Does It Cost to Build a House with Natural Stone?

Natural stone is a more expensive choice than stock bricks. Using cropped coursed stone blocks to form an independent outer leaf of a cavity wall (with a blockwork or timber frame inner leaf) works out at a very similar cost to handmade brick.

Using reconstituted stone costs much the same for labour, but slightly reduces materials costs.

Building using traditional random stonework is slower and although the materials cost is similar, the labour cost is higher, making it more expensive. The most cost-effective option is using them at a depth of 250mm against full-fill cavity insulation and waterproofed blockwork (if acceptable to Building Control in your area).

Building against a backing block to form a cavity, with an inner leaf of blockwork or timber frame, will add around £20/m².

a porch clad in stone cladding

The most cost-effective way to create a natural stone façade is to use stone cladding as an external finish.   (Image credit: LBS Products)

How Much Does it Cost to Build a House with a Rendered Finish?

Sand and cement house rendering on blockwork is one of the cheapest options, especially if it is self-coloured using white cement and local sand, so it does not require painting (which typically costs around £10/m² or £2,200).

Adding lime will make the render more forgiving but will marginally increase costs. Modern polymer renders are more flexible but add more to materials costs.

white rendered rear kitchen extension

Your choice of cladding material can drastically affect your build costs. (Image credit: Mo Photo c/o KE-Design)

How Much Does it Cost to Build a House with Cladding?

Painted softwood shiplap can prove a cost-effective choice, especially on a timber frame structure, where no backing block is required. Dense timbers such as oak, western red cedar and sweet chestnut, and also heat-treated softwood such as larch, are good choices and comparable in cost to using a good-quality brick.

(MORE: Cladding a House)

How Much Does a Roof Cost?

builders using structural insulated panels to build a house

(Image credit: Kingspan)

Roof costs are made up of:

  • the structure
  • insulation
  • felt and battens
  • roof covering
  • flashings/detailing.

The cheapest option is to build a simple rectangular-format low-pitched roof using manufactured trusses.

The low pitch means the rafter lengths are shorter, using less timber, and the manufactured trusses use a web of thinner timbers, again reducing materials costs.

The more complex the roof structure, the more likely it will have to be cut on site, using more labour and timber than factory-made trusses. This will add to costs and take longer to construct.

It will also require an engineer to check the design and produce calculations for Building Regulations purposes for a fee that would otherwise be covered by the truss manufacturer. More complex roof designs may also require structural steelwork.

Pitch Cost Considerations

The steeper the roof gets, the more expensive the roof will be to construct. As a rule of thumb, increasing the roof pitch by 5% will double the cost of the roof, while increasing it by 10% will triple it.

Roof Coverings

When it comes to roof coverings, developers favour large-format, interlocking concrete roof tiles with a coverage as low as 8–10 tiles/m², keeping labour and materials costs down. Most self builders choose more attractive, smaller-format tiles made from natural materials such as clay roof tiles, or slate. Unfortunately, smaller tile formats will increase labour and material costs.

If you plan to use a roofing material other than that allowed for in the average costs (£20/m² Standard, £40/m² Good, £80/m² Excellent) you need to add an allowance for the net difference in cost. If you decide to go for decorative details to the ridges or verges, or to use very irregular handmade tiles, this will add to the cost of labour and materials.

How Much Does the Floor Structure Cost?

Concrete slab, suspended timber or beam and block? All are viable choices for your ground floor structure.

The standard specification for first floors is to use softwood joists covered with flooring grade chipboard; the cost of which is £16–£19/m² (approximately £3,200–3,800).

Using engineered joists such as I-beams or beams with a steel web such as Posi-joist will add to your costs by £2–£3/m² (£400–£600), but the more regular dimensions and improved stability can help avoid squeaky floors.

If you are building a masonry or concrete (ICF) house, you could opt for a concrete first floor structure, using either pre-stressed concrete beams infilled with concrete blocks or large-format concrete floor panels.

This offers superb strength and acoustic separation, and allows you to have masonry first floor walls throughout. This specification will add to your costs by £8–£12/m² (£800-£1,200).

How Much Do the Walls and Ceilings Cost?

There is little cost difference between blockwork and timber frame internal partition walls.

Developers looking to keep down costs work with a standard ceiling height of 2.4m. Changing the ceiling height adjusts the average cost/m² for that storey by approximately 1.6% for each extra 100mm (meaning a 2.7m ceiling height on the ground floor adds £4,800 to the total costs).

Following industry standards allows you to use industry standard sized materials such as plasterboard on your walls.

drylining a ceiling

(Image credit: getty images)

Costs are similar for both wall finish options (wet plasterng walls or dry-lining). The standard specification assumes emulsion paint throughout, with minimal tiling to kitchen and bathrooms at £64/m² (£14,080).

The good specification includes more tiling in the kitchen and bathrooms and wallpaper in the living room at £80/m² (£17,600). The excellent specification also includes wallpaper to the bedrooms at £96/m² (£21,200).

Ceilings are usually covered with plasterboard and finished with a two-coat skim of fine gypsum plaster and emulsion paint at £17–£20/m² (£3,700). If you decide to add decorative coving, ceiling roses or other decorative plasterwork, you will need to allow for extra.

How Much Will My Staircase Cost?

modern staircase ideas in living room

More complex staircase designs will add to the cost of your build.  (Image credit: Bisca)

The main staircase is an opportunity to add individuality to a property and to make an architectural statement. If this is your plan, make an additional allowance for this above the staircase allowance included in these build costs.

The standard specification solution is a softwood staircase consisting of two straight flights linked by a half-landing, with a softwood balustrade, painted or stained, at a cost of around £1,250.

The good specification includes a single straight flight in painted softwood at around £1,500, while the excellent specification allows for a straight flight in hardwood, with hardwood balustrade at around £2,150. Obviously this is removed from your total build cost if you’re building a bungalow.

(MORE: Staircase Design)

How Much Does a Chimney Cost?

Many modern houses do not include a chimney — especially those built by speculative developers, largely because of the cost, which starts at £6,100 for a standard specification. Many modern houses also forgo a traditional open flue chimney in favour of a log burning stove and stainless steel flue, at an installed cost of around £1,650–£2,500.

The standard specification has an allowance of £6,600 for the fireplace and flue; the good specification has an allowance of £8,300, and the excellent £11,300.

How Much Do Windows and Doors Cost?

inside of a flat roof extension with a roof lantern and bi-fold door

(Image credit: Korniche)

External joinery is another feature that self builders place a great deal of value on, and consequently tend to invest in quite heavily.

  • The standard specification house has off-the-shelf painted softwood casement windows and external doors, with double-glazed units and factory-fitted aluminium ironmongery at a cost of £60–86/m² (£13–£19,000)
  • The good specification includes high-performance, off-the-shelf painted softwood casement windows and external doors at £81–£107/m² (£17–£23,500)
  • The excellent specification includes double-glazed aluminium window frames in hardwood surrounds and a hardwood panelled front door and good-quality ironmongery at £121–£146/m² (£26–£32,000)

If you want to go for bespoke window styles, get a quote from a joinery supplier and substitute their price for the allowance/m² (joinery allowance for your chosen specification multiplied by your gross internal floor area).

This is another area where many self builders choose to make an upgrade from a standard specification.

  • The standard specification includes hardboard-faced hollow-core flush doors in softwood frames, hung and decorated at around £250 per door (£4,000 based on 16 doors) including all ironmongery
  • The good specification includes slightly better hollow-core flush doors in softwood frames, hung and decorated at around £350 each (£5,600)
  • The excellent specification includes hardwood veneered solid-core doors in softwood frames, hung and decorated with quality ironmongery at around £450 each (£7,200)

If you plan to put in more expensive doors, you will need to account for this in the total build cost.

How Much Does a New Kitchen Cost?

a bespoke kitchen in blue by martin moore

Bespoke kitchen designs can cost anywhere between £25,000 to £50,000+. (Image credit: Martin Moore)

How much does a new kitchen cost? Well that depends, on the quality and style, ranging from off-the-shelf cheap kitchens to designer bespoke kitchens

For a new kitchen, you're looking at prices from £5,000 (budget range, DIY installation) to £50,000 (high end bespoke kitchen, installed). 

(MORE: How Much Does a New Kitchen Cost?)

Kitchen Costs
Price starting from
Standard£8,000-£10,000
Good£15,000-£20,000
Excellent£25,000-£50,000

How Much Does a New Bathroom Cost?

an ensuite idea with an open plan scheme

(Image credit: BC Designs / VADO)

Plumbing costs are much the same regardless of the specification you choose, but the cost of sanitaryware and brassware varies enormously. The quality and area of tiling on the floor and walls varies from £23/m² upwards, and then you can add showers and enclosures, heated towel rails, underfloor heating, luxury baths and more.

The costs in the tables allow for two bathrooms and one cloakroom at the relevant cost. If you plan to fit more bathroom facilities, or better quality facilities, then use the typical cost allowances below to allow for this in your overall build cost.

(MORE: Bathroom Design)

Bathroom Costs
Bathroom (WC, basin, bath and additional plumbing, doors, walls, windows and finishes)Shower Room (WC, basin, shower cubicle, doors, walls, windows and finishes)Cloakroom (WC, basin and additional plumbing, doors, walls, windows and finishes)
Standard£3,500£3,700£1,900
Good£5,400£5,600£2,700
Excellent£8,700£9,200£3,600

Working out the Cost of Fixtures, Finishes and Utilities

Although the cost of many of the construction elements such as the foundations do not vary based on quality, the cost of external facings, joinery, flooring, fittings — and renewables — can potentially double the cost of building the same house compared to a standard specification.

This section covers:

How Much Will Flooring Cost?

Flooring Costs (laid prices including painted softwood skirting)
Standard£20–25/m²
Good£30/m²
Excellent£43/m²

Alternative Floor Finishes
Contract-quality carpet£20–25/m²
100% wool carpet£45–55/m²
Laminate (wood effect)£20–25/m²
Engineered oak flooring£60–65/m²
Reclaimed pine floorboards£40–50/m²
Natural stone flags£70–80/m²
Ceramic tiles£50–70/m²

How Much Does Built-In Storage Cost?

Built-in storage ideas are already allowed for within the costs at roughly £20/m², £30/m² and £40/m² for standard, good and excellent specifications.

How Much Does a Heating System Cost?

A standard heating solution is a radiator system with a gas boiler and basic controls. A standard central heating system will cost £18–£23/m² (£4,000–£5,000) and this is the allowance in the average build costs.

Underfloor heating is typically more expensive, so allow £30–40/m² (£6,600–£8,800). If you want renewables, add this in to your budget accordingly. The standard costs allow for the inclusion of a MVHR system, around £1,600 for houses under 150m² and £2,100 for larger houses.

How Much Will the Electrics Cost?

Standard costs do not vary much from house to house other than by scale. If you decide to fit anything out of the ordinary (e.g. a whole-house structured cabling network), you will need to make an allowance for these upgrades.

Electrics Guide
Standard£37–45/m²
Good£45–50/m²
Excellent£46–57/m²

Electrical additions (per room)
Low voltage down lights (7)£350–400
Structured cable network£200–250
Built-in hi-fi£400–600
Separately switched 2a lamp circuits£250–350
Security alarm system£600–1,500+

Hidden Fees When Building a Home

  • Legal Fees: £500-1,000
  • Stamp Duty and Land Tax: Until 30 June 2021, the first £500,000 of all property sales is exempt from stamp duty
  • Topographical Site Survey: Typical cost £350-500
  • Design Fees: Architects charge 7-15% of the total build cost for a ser­vice involv­ing design and supervision. For planning drawings from other sources expect to pay from £2,500-£3,500, plus a similar figure for Building Regulations drawings
  • Structural Engineers’ Fees: £400-£500
  • Planning Application Fees: £462
  • Building Regulations Fees: £500-£1,000
  • Warranty: Around 1% of contract value
  • Self Build Insurance: Typically 1% of the projected build costs
  • Services: Typically £3,500-£6,000 total
  • Demolition Costs: Typically £5,000-£10,000
  • External Works: Around 15% of total build cost
  • Preliminaries: such as setting up a site office, scaffolding, fencing, security and safety equipment and skips. Typically costs £5,000-12,000 for a new house.

VAT on Self Builds

VAT can be a painful addition to bear in mind for any project that applies to both services and materials for your build. However, for the right new build of a 'dwelling in its own right', you're able reclaim all of the VAT on a new build that you have paid out during the course of the build. 

This VAT exemption extends further than you might think, and you can reclaim correctly paid VAT on everything from the material used to build the house down to fitted furniture such as the kitchen (but not appliances) and flooring (but not carpet).

You must keep and submit the original VAT invoices to HMRC to be eligible to claim back VAT on your build. 

What Factors Affect Build Cost?

The bigger the house, the more it will cost to build, but there can be some economies of scale that reduce the average cost/m² for larger houses, making a carefully-designed large house better value.

The savings are mainly in the cost of building the superstructure, especially the foundations, walls and roof. The cost/m² of gross floor area for external walling elements decreases as the wall/floor ratio decreases.

Other one-off unit costs for items such as service connections, staircase, kitchen and boiler are spread out further on a larger house. To maximise efficiency, the design needs to be kept simple and avoid unusually large spans for floor joists/beams, rafters etc.

(MOREHow to Build a House for Under £150,000)

a kitchen with curved walls

Straight walls are cheaper to build than curved walls.  (Image credit: WoodWorks Brighton)
Top Tip

If you want to get the maximum development return on a site, it often pays to build as many storeys as possible.

The specification and cost for a set footprint and roof layout will not vary whether the design is single storey, two storey, or three storey, yet the overall area of the design will increase dramatically — spreading out the cost.

Multiple storeys also make better use of land, which is the most expensive element of all.

The cost of constructing a basement largely depends on the digging out and removing of spoil. This cost – and the cost of waterproofing the structure – is mitigated to some extent by the fact that fewer windows are usually used than for above-ground storeys, and there is no external wall cladding (e.g. brick or stone).

As ever, the quality of fixtures and fittings will be a major factor in the final cost. For the purposes of producing a budget figure for your basement, measure the gross internal floor area and use the same costs/m² as for above-ground space.

How Much Does a Project Manager Add to the Cost of Building a House?

a self build home with a stone clad exterior

Self builder Alan Williams took on much of the construction work of his home, helping to reduce the build cost to £150,000.  (Image credit: Alistair Nicholls)

In order to get a building site to run smoothly, someone has to manage the processes. They have to ensure that the right people are hired in the right order and that the correct materials are on site as and when needed, as well as checking that the work is carried out properly and that the site is left clean and safe everyday.

The average build costs are based on the cost of using a main contractor to manage the whole build.

They will:

  • co-ordinate the trades, materials, plant, tools and scaffold
  • liaise with the architectural designer
  • co-ordinate the statutory inspections for Building Regulations and warranty
  • take legal responsibility for the site.

If you take on this role by hiring subcontract labour directly, providing materials and facilities as required, you can reduce the build cost by 10-15% depending on how efficiently you manage the project.

(MORE: Self Build Project Management)

Approximately 35% of the total cost of building a house is labour, so if you decide to substitute some or all of the labour costs with your own DIY labour, you can reduce the average build cost substantially.

You can undertake almost every aspect of the building work if you have the time and skill to complete it competently, except for connecting gas appliances.

Trades more easily undertaken by the DIY self builder include:

  • carpentry
  • fitting insulation
  • roof tiling
  • general labouring
  • assisting plumbers and electricians on second fix
  • decorating
  • floor laying
  • tiling
  • landscaping.

Typical savings for a DIY self builder doing roughly 25-30% of all the work amount to 20-25% of the total cost compared to using a contractor.

So how much does it cost to build a house for each of these routes? You can use these figures as a starting point for your build — this excludes VAT which, as we've already mentioned, you maybe able to claim under the self build VAT exemption. 

  • DIY: £650-1,050/m2
  • Self-managed: £1,050-£1,450/m2
  • Main contractor: £1,250-£1,750/m2 
  • Design and build: £1,450-£2,250/m2 

On larger projects, a professional is usually retained to put the project out to tender, appoint the contractor and administer the contract through to completion.

The fee for this is typically 3-5% of the total contract value (construction cost). If you take on this role yourself you can save this fee (which isn’t included in our base figures).

Michael Holmes

Michael is HB&R’s Head of Content and Product Development. Michael is also, Chair of the National Custom and Self Build Association (NaCSBA), presenter of multiple property TV shows and author of Renovating for Profit (Ebury). Michael is a regular in the seminar theatres and Advice Centre at the Homebuilding & Renovating Show.