Design Ideas, Self Build
25 July 2022
Grand Designs is without doubt my favourite show! But I’m always amazed at the final cost to build a house.
I love watching people create those jaw dropping spaces that many of us can only dream of.
Although I do love to see the final walkthrough, the most interesting part to me is the problems self-builders have along the way. I’m also always impressed at the creative solutions needed to solve them while keeping in mind the cost to build a house, and the restrictions that a budget might bring.
Although we all want to live in our dream home, the process can be hugely complex and time consuming.
To help you at the start of this exciting journey, I thought it might be helpful to prepare this guide.
It covers all the various stages involved in building your new home and the associated costs.
How much does it cost to build a house?
|House Type||Low ||High|
|Average cost / m2||£1,800||£2,300|
|3 bedroom house (100 – 120m2)||£198,000||£352,000|
|4 bedroom house (140 – 200m2)||£306,000||£544,000|
|5 bedroom house (220 – 260m2)||£432,000||£768,000|
Cost to build a house per m2
Factors affecting the cost of a new house: The reason why it’s difficult to estimate exactly how much it will cost to build a new house is because there are almost an infinite number of factors involved. The biggest four factors are:
– Size of the house
– Design complexity
– Fixtures and fittings
A small change to any of these can have huge knock-on effect to the overall construction cost to build a house.
Quick method to estimate build cost: Most property developers and builders will start by answering two simple questions.
– How many m2 will my new house be?
– What is the price per m2 to build the type of house I want?
Surprisingly, this method is quite accurate. The most difficult part here is obtaining an accurate figure per m2 for the build cost. Recently, the cost of both materials and labour have increased significantly.
Location: Where you live often plays an important part which determines how much construction costs are and how much builders will charge.
For example, in London, it can cost anywhere between £3,000 – £3,300 per m2 to build a new house. To obtain an accurate construction cost figure we would always suggest speaking to an architect or builder. The chances are they will be mid construction on a few new houses, meaning they can simply refer to their spreadsheet to obtain an accurate figure of how much each m2 costs to build.
Ways to Finance your new house
As the cost to build an average size 3-bedroom house could be approximately £500,000, we appreciate that is a huge amount of money. Wouldn’t it be nice if we all had that much sat in our bank accounts? A great thought, but unlikely.
While you may not have the entire amount in cash to build a house, if you choose to get a self-build mortgage you could borrow up to 95% of the total construction cost which means you still need to find that 5%. That works out as just £25,000 if the total build cost is £500,000, which is certainly much more realistically achievable.
2. Sell your existing home
What’s important here is how much equity you have in your existing home. The quickest and easiest way to work that out is to first have it valued by a local estate agent. Make sure they use recent comparables from your street when finalising their valuation.
For example, if your agent tells you that your house is worth £500,000 and you purchased it for £250,000 10 years ago, if you bought it with an 80% interest-only mortgage of £200,000, you would be left with equity of £300,000 (before selling costs).
While that may not be enough to pay for the entire build, it will certainly help with the deposit for a self-build mortgage.
3. Self-build mortgage
Staged payments: The main difference between a self-build mortgage and a normal mortgage is the staged payments. As there is no physical asset before you start building, the bank will release your mortgage in stages as you hit particular milestones throughout the construction process.
Loan to value ratio: Lenders will typically let you borrow up to 85% of the total construction cost.
Interest payment: The second advantage of this route is that you only pay interest on the amount of money you have borrowed up to that stage. It’s not based on the total amount you borrow as traditional mortgages are.
Completion: Great news! You’ve now moved into your dream home. At this stage, you can switch to a traditional mortgage which often means far lower interest rates as there are fewer risks for the lender.
4. Remortgage your existing home
Self-build vs normal mortgages: As there is more risk involved with self-build mortgages, the interest rates might be higher. For example, a self-build interest rate could be 4% while a traditional mortgage could be 2%. Bearing this in mind, you might decide to re mortgage your existing house to fund your cost to build a house.
Early repayment fees: When going down this route, make sure you have taken into account any early repayment fees from your lender. If you know your new build house will take no longer than 2 years to complete, try and find a mortgage offer with a 2-year term. Once your new home is complete you can then sell your old home and pay off the mortgage.
Pre-build costs to budget for
Before your builder starts laying any bricks it’s important to have a good understanding of the costs you will have to pay first. Here are some of the most common costs you should expect for an average size 130 m2 detached house in addition to the land:
|Land survey costs||£500 – £800|
|Electricity and internet||£3,000 – £4,000|
|Gas||£2,000 – £3,000|
|Architect’s fees||6 – 12% of the construction cost|
|Structural engineer||£5,000 – £7,000|
|Building regulations||£1,500 – £3,000|
|Insurance||1% of the total build cost|
Once you have deducted all these costs from your budget, that is the amount of money you have left to complete your new house.
Breakdown of individual costs
The average cost to lay foundations is around £100 – £150 per m².
Ground conditions: It’s difficult to predict the exact cost of foundations before your builder starts on site. This is because the type of foundation used will vary depending on the particular ground conditions. You will only find that out when your builder digs some trial pits to see what type of ground you have.
Uneven ground: If your site is relatively flat, digging and pouring the foundations will be straightforward. However, if your site is on a slope this means the concrete foundations will need to be stepped which often means ‘shuttering up’. Shuttering up involves creating a frame for your concrete to be poured into. This involves more labour which pushes the overall cost to build a house up.
Trees: The presence of trees, especially with clay soil, will further complicate the foundations. This is because the presence of tree roots will affect the moisture content in the soil. Clay soil tends to expand or contract with different levels of moisture.
The different construction methods
Brick and block: This is the most popular construction method for building new houses in the UK. It involves an inner skin of breeze blocks and an outer skin of brickwork. Load bearing internal walls will also be made of blockwork while non load bearing work will be timber studwork. The cost is approximately £80 – £100 per m2.
Timber frame: Around 25% of new homes in the UK are built from panelised timber frames. One of the advantages of this system is that the frame acts as a super structure, meaning you don’t have to have any load bearing walls. This method is fantastic for those of you who prefer open plan living. In terms of cost, it’s slightly more than brick and block at around £100 – £120 per m2.
Insulating concrete formwork: This system involves stacking lots of polystyrene blocks together which are then filled with concrete. This means the walls are well insulated and airtight. The main disadvantage of this system is that it requires a builder with experience of using it. This may involve hiring a specialist sub-contractor. This system is a similar cost to the timber frame above at about £100 – £120 per m2.
Structural insulated panels: This method is similar to the timber frame option above. The panels are made up of two layers of oriented strand board (OSB) bonded around an inner core of insulating material. As the panels are all prefabricated off site, this means great quality control. It’s also a far quicker process in terms of construction time. The cost is approximately 15% higher than a standard timber frame. Bear in mind that you will also save on labour, which can compensate for the increase in price.
The average cost of having a beam and block floor system is somewhere in the region of £200 – £300 per m².
Beam and block: Precast reinforced concrete beams are laid in rows, similar to what you would expect to see with wooden joists. These T shaped beams are then inverted so that concrete blocks can be placed in between. It’s important that no sharp blasts of air can carry up through the void below and through the floor. This is why insulation boards are placed over the top of the beam and blocks once installed.
Hollow core: This method involves craning in prefabricated hollow concrete floor panels. Although the upfront costs of this system can be high, there are two main advantages. First, they are quick to put together, thus decreasing the overall build time. Second, you have more flexibility in terms of internal walls, which can be built on top without the need for additional supports.
Concrete: The advantage of this system is that most builders have a lot of experience using it. The cost of concrete is also relatively cheap, thus saving on materials. However, it is quite labour intensive when compared to some of the prefabricated options highlighted above. The second disadvantage of this method is that as it’s a solid foundation, it sits only 500mm below ground level (unlike traditional trench foundations which might be over 1m deep). If your site is on clay soil or close to large trees, we would not advise this option as such soil is prone to seasonal movement.
Second to the groundwork, your roof will be one of the largest parts of the new house to build. They vary in the amount added to the cost to build a house depending on the size and style of roof you go for. You should expect to pay over £15,000 for a new roof.
In terms of cost, the materials are relatively inexpensive, and the majority of builders will be very well acquainted with this construction method.
Flat roofs: Flat roofs are relatively inexpensive to build and fit. However, it wasn’t until the 1950s that cheap and effective materials became widely available. In terms of cost, it really depends how much you want to spend. GRP roofing systems are relatively inexpensive and easy to fit. There are also copper or even zinc alternatives which look stunning but can be far more expensive.
Structural insulated panels: Structural insulated panels are becoming increasingly popular. They are prefabricated off site and craned in. The advantage of this system is that they are pre-installed and they are also speedy to erect, which saves a huge amount on labour. The only disadvantage of this system is that the panels themselves can be expensive.
Cladding is a fantastic way to transform the look of your new house into something spectacular without adding too much to the cost to build a house. Even better, there are lots of different options to choose from. Below are some of the most popular:
Wooden cladding: For those of you on a budget, this can be a fantastic option to create a fresh and modern unique design. Boards can be found for as little as £5 – £8 per m2. The only disadvantage of these systems is that they need to be primed and painted. After a few years they can begin to weather so will need to be repainted every so often to keep them looking fresh.
Brick slips cladding: Brick slips are essentially panels which give the exterior finish of a brick but much thinner. They’re also hung from an existing structure which means they’re far quicker to install than laying traditional bricks. There are also a huge range of different types to choose from. Brick slips cost approximately £20 per m2.
Shou Sugi Ban cladding: This has been around for hundreds of years in Japan but is now becoming more popular in the UK. It involves running a blowtorch across timber boards to char it leaving it with a fantastic black finish unlike any other material. They can also be fitted on site far quicker than any brick layer and at a fraction of the cost. The cost per m2 starts from approximately £120.
Vertical hanging tiles: For those of you going for a slightly more traditional look, clay hung tiles might be the perfect answer. They involve hanging tiles from the exterior walls. Bear in mind this is a relatively expensive option in terms of materials and labour to fit them. Both the materials and labour can be up to £80 per m2 and one of the more expensive options.
Rendering a house: Rendering your house can also be a very popular option. Render can be made of cement, acrylic or silicone and acts as a weatherproof layer over your brick or blockwork. The great advantage of this system is that it is quick and easy to apply and also comes in a huge variety of colours, helping separate your new house from the neighbour’s. For render, expect to pay between £50 – £60 per m2 added to the cost to build a house.
Plan for the long term: When planning your drainage system, make sure that it is future proofed. This means making sure there is sufficient hydraulic capacity to meet your future demands. For example, perhaps you plan on adding some extensions in the future? Also make sure there are enough access points so future maintenance is quick and easy to carry out.
Sustainable Urban Drainage Systems (SUDS): SUDS are a collection of water management practices that aim to align modern drainage systems with natural water processes and are part of a larger green infrastructure strategy. Many floods in the UK are due to a lack of SUDS awareness.
The reason is because with all the new development going on in cities, lots of areas which were previously green and would absorb water are now concrete. This means that during periods of heavy rain the water has nowhere to run. Make sure you incorporate some SUDS features as it will help prevent the build-up of water around your house. This could be as simple as a permeable driveway rather than using tarmac.
Create a drainage plan: Make sure your architect creates a very clear drainage plan before work starts on site. Not only will this act as a perfect blueprint for your builder, but it will also be useful when maintaining your system in the future.
Arrange a CCTV survey: When it comes to new build houses, as the entire drainage system is new, it can be a sensible idea to carry out a CCTV drainage survey once complete to double check there are no issues or leaks. These can be costly to fix if they go undiscovered for long periods of time.
The cost to wire an average 3-bedroom new house can range from £5,000 – £7,000. While wiring a 5-bedroom house it is likely to cost between £10,000 – £15,000.
Plan the location of your outlets: This may seem obvious, but careful thought of the layout before your electrician starts on site will help your home be more practical. For example, you probably want the desk in your home office to be opposite the window due to the reduced glare. This means installing more sockets in that space. Where will your TV go in the living room? You may also have a Sky box, TV, sound bar, computer console, lamp etc to fit here. So make sure you plan ahead. It’s much better to have too many sockets than too few. Good planning will mean you won’t need to add anything onto the cost to build a house further down the line.
Know if you need extra power: Smart homes are becoming increasingly more popular. All these items will require more power than you might think, so make sure your new house can accommodate future changes.
Energy efficiency: Building your new home is a great opportunity to do your part for the environment and also reduce your energy bills. New tech is coming on leaps and bounds. Look into: temperature sensors, smart lights or smart thermostats. These systems can help your house adjust energy use to the cheapest power at different times of the day.
Use customisable lighting switches: We all have light switches in our homes, but have you seen the new LED based control panels? You can also now get USB charging cables in sockets for charging mobile phones.
What is the boiler ban? The government have banned new homes being built with gas boilers after 2025. This will help the UK reach its zero-carbon emissions target by 2050. Bearing that in mind, it might be worth thinking ahead when it comes to heating your home.
There are 3 main options to choose from.
Electric radiators: Electric radiators use a mixture of radiation and convection to keep rooms warm. As these radiators don’t require pipework, they are much easier to install when compared to traditional gas systems. They also don’t need space for water, so many are slim line, taking up minimal space. Another plus is that most new electric radiators are Wi-Fi enabled. You can control them all individually or collectively with a quick touch of a button.
Infrared Panels: Infrared panels are slightly different to normal radiators as they don’t use convection. Instead, they use infrared radiation to provide a gentle level of warmth.
Heat pumps: Heat pumps are also a great alternative to gas. They work by transferring heat energy from one place to another. The water is usually heated from the ground or air outside. Not only does this solution provide heat for your home but it is also designed to heat water, so you kill two birds with one stone. The main downside is that heat pumps are very expensive to install, requiring a lot of labour too. Ground source heat pumps can cost anything between £18,000 and £30,000 on top of the cost to build a house.
The average rate for a carpenter is around £200 per day.
Jobs you might need your carpenter to carry out:
- New kitchen
- Fitted wardrobes
- Fitted bookshelves
- Fit skirting boards
- Lay flooring
- Hang a door
Builder: At this stage, you will be nearing the end of your project, but remember that the devil is in the detail. Good carpenters are hard to find. When agreeing a price with your builder, double check if they employ carpenters directly. If your builder plans on subcontracting the carpentry out, ask if they have worked together before.
Hiring and paying a carpenter: If hiring your own carpenter, make sure you’re both clear on what needs to be carried out before work starts. It’s also important to ask how long it will take and how payment will be made. If the job requires a carpenter to purchase lots of materials, it’s normal that they would ask for a deposit before works starts. You should never pay the full fee in advance. Always leave some back, payable once you have checked and agreed their work.
A typical 3-bedroom terraced house costs around £600 to £700 per room to plaster, plus £200 to £350 for each ceiling.
Difficulty comparing quotes: If finding a plasterer yourself, it’s sometimes quite difficult to compare different quotes. The solution is to ask the plasterer how much they charge per m2. This will make it far easier to compare all your quotes and understand how much the job would add onto the cost to build a house.
Accessibility: If your new house has ceilings higher than 2.5m, it may be that your plaster needs scaffolding in order to reach the top of the walls and ceilings. If this is the case, make sure to confirm whether this is included in their quote.
|House Size||Estimated Cost||Time Required|
|1 bedroom flat||£1,000 – £1,300||2 – 3 days|
|2 bedroom flat or house||£1,500 – £2,200||3 – 5 days|
|3 bedroom house||£2,400 – £3,100||5 – 7 days|
|4 bedroom house||£3,300 – £4,000||7 – 10 days|
|5 bedroom house||£4,200 – £6,100||10 – 15 days|
Pricing structure: We always think it’s best to opt for a fixed price for all the agreed work rather than paying decorators on a day rate. When paying them for each day, they have little incentive to finish the job quickly. If the job takes them longer than expected, day rates are an easy way for costs to quickly spiral out of control. Also, always remember to ask if their quote includes VAT.
Materials: Decorators will be able to buy paint using their trade discount, so make sure you’re taking advantage of that. Make sure you ask what brand and type of paint they’re planning on using. e.g. the cost of Dulux or Farrow & Ball can be 3 times more expensive than a retailer’s own brand. To avoid any issues, the best option is to go and pick the exact paint you want for walls, ceilings, spindles, skirting boards etc. Let you painter know and he can then purchase the paint on your behalf.
On average, a good tiler should charge between £30 – £40 per square metre.
Style and design of tiles: Plain tiles are easier to fit than elaborately patterned tiles. So, if you have a complex pattern you would like to match perfectly throughout your bathroom, expect to pay a little more on top of the cost to build a house. Mosaic tiles also look fantastic but are very fiddly and can take longer to lay.
Size of the area being tiled: Always make sure you have accurately worked out the number of m2 you’re having tiled before asking for a quote. It’s also important to make sure your tiler has seen the space beforehand. If you have uneven walls, sloped surfaces or cramped conditions, it will be a more complex job so your tiler might charge a little more.
Paying your tiler per-metre or per-day: Some tilers are quicker than others. So, it may be that some decide to quote a day rate, but make sure they let you know how many days. If they end up going past the deadline, it would be down to them and you shouldn’t be expected to pay any more.
Natural stone floors: The cost scale probably starts with sandstone at the cheaper end, followed by travertine, slate, limestone and marble, ending up with granite. Prices can range considerably, starting from around £50 per m2 and going all the way up to £150 per m2.
Floor tile costs: There are a huge number of alternatives to natural stone which could include: quarry tiles, terracotta, flooring-grade ceramics. Porcelain tiles are one of the most popular choices and can start as little as £20 per m2. As manufacturers begin to innovate, the size of tiles is now becoming larger which is fantastic if you have a larger space.
Engineered wood & solid timber: The cost of this type of floor typically ranges from £25 – £45 per m2. The advantage of engineered wooden floor is that it doesn’t heat or curl (as real wood floors do) in response to humidity and heating levels.
Vinyl and laminate floors: These floors are becoming increasingly more popular. They are essentially clear resin-coated photographic images fixed to a vinyl sheet. As they are created from photos, there are a huge range of different styles and designs. Prices can start from as little as £20 per m2.
Do I need a project manager to build a house myself?
An experienced Project Manager will charge between 5% – 8% of the total construction cost, so make sure you add this into your budget for the cost to build a house.
Project manager tasks
- General management
- Problem solving
- Quality-checking and diplomacy
- Knowledge of construction practices
- Appoint individual contractors, trades, suppliers and services
- Decide when each one needs to be on site
- Call in quotes from contractors
- Negotiate the pricing structure
- Confirming contracts and tenders
Can I project mange myself?
You can, but….
Taking on all the above tasks is a huge responsibility and far more complex than managing a traditional extension project. Also, it’s not only the cost. Managing the above processes is a full-time job and can save you a huge amount of money in the long run. Not to mention the fact that your dream home will be completed sooner if the entire construction process is managed efficiently.
Can I Reclaim VAT on a self-build?
The short answer is YES, but it’s not a simple process.
Under the DIY housebuilders’ scheme, you can apply for a VAT refund for the following projects:
- Building a new home
- Converting a property into a home
- Building a non-profit communal residence, for example a hospice
- Building a property for a charity
The government’s website includes a lot of information with regard what qualifies for a VAT exemption and also how to claim it back. Click here to find out more.
Is there a construction materials shortage?
In 2021, the cost of construction materials soared as a huge spike in demand coincided with supply chain issues caused by Brexit and the COVID-19 pandemic. This means the cost of materials and labour have soared in recent years. To obtain an accurate quote from a builder, we would always advise obtaining a schedule of works or a bill of quantities from a surveyor. This will help your builder price each individual element and give you an accurate quote for the cost to build a house.
Is it cheaper to buy or build a new home?
It can be cheaper to build a new home, if you’re careful.
It is possible to build a new house for less than it would cost you to buy a new house from a developer. However, this is only if you can stick to the budget. Quite often people take on the task to manage the process themselves without a Project Manager which can lead to uncontrolled spending. This can kill any profit margin and make your new house more expensive than buying.
How long does it take to build a house from start to finish?
For an average 130 m2 detached house, the build should take approximately 12 months from start to finish.
However, that does not include the time it takes to purchase the land, or the design and planning stages.
Can I get a loan to build my house?
Yes you can!
There are a number of high street lenders who loan money for self-build projects. The application process can be a little more complex when compared to a traditional mortgage and the funds are released in stages throughout the construction process to cover the cost to build a house.
What will be the biggest cost when building your own house?
The biggest cost in your project will be the structural elements of your new house. This includes:
- Structural walls
- External cladding
We expect these costs to be approximately 35%+ of the value of the total construction cost.
Designing your dream home from the ground up is an exciting process.
However, it’s also time consuming for those of you who might not have been thought the process before.
At Adara, we’re a team of experienced architects and planning consultants. We have a huge amount of experience in working with people to create their dream homes.
If you have any questions or would like to discuss ideas, why not book a free 30-min consultation with one of our architects?
We look forward to hearing from you.