How much does it cost to build an extension?
Building an extension has many variables, so providing a fixed price in this blog is going to be impossible, especially with the eye-watering increases we have seen in recent years. The aim of this blog is to inform so that you can have a better idea of what budget you may need for your extension and the areas that impact on the cost.
The cost to build an extension depends on the size the extension you are planning to build will be. Is it going to be a single storey extension, a double storey extension or maybe even a wrap-around extension? What type of finish for the inside are you looking for? Will you incorporate a bathroom or kitchen within your project? These rooms can add thousands more to your budget.
Below are some rough numbers that can help give you a general idea.
Professional Fees
You will need to factor in professional fees for the architect, structural engineer, planning application and building regulations. This will be several thousands of pounds, especially if your project is complex.
Building costs
The structural build alone is likely to costs in the region of £2,000+ per m2. To calculate the m2, measure how long and wide your extension is going to be. The cost to build an extension would need to be doubled for a double storey extension.
How many windows are required?
Think carefully about the windows and how much natural light you would like to bring into your extension. If it is a rear extension, would you like bi-folding doors to connect the outside with the inside? Do you need skylights to bring in light where the existing property boundary meets the extension? You can of course keep it simple and budget friendly, but if you hate dark spaces, you may want to consider increasing the budget for this area to let the light shine in.
Good insulation
If you want a cooler house in the summer and a warmer one in the winter, don’t overlook insulating when you build an extension. Talk to your builders about the insulation choices that are on the market and invest in the best that your budget will allow.
The taxman’s cut
And let’s not forget about VAT, which is currently at 20%. HMRC will be profiting from your build!
Kitchen or bathroom installations
Things will get a lot more expensive when you start thinking about kitchens and bathroom installations. If you’re planning your dream kitchen and are considering a shower room downstairs for guests or a growing family this will add significantly to your budget. For a bathroom, you are probably looking at upwards of £5,000 and for a kitchen from £10,000 upwards.
Finishes and fittings
If you’re happy with painted walls, carpet or laminate floors, and standard light fittings then your costs will be at the lower end. But if you are in your ‘forever home’ and you want the latest fittings, finishes and gadgets, your costs can quickly escalate. Think carefully about what you want and what works for you and what you can afford.
How to choose the right builder
We recommend getting quotes from 3-5 builders for any extension to your home. That way you can get a feel for what the market is offering. Are they responsive, friendly and respectful? Did you get a written quote in a timely fashion? Did it detail the scope of the project? Are they properly insured for the work that they are going to undertake? Doing this research will not only give you a better sense for the market rate, but it will also give you a feel for different building firms and how they operate if they take on your project. Remember, they are going to be at your home for several weeks!
Planning a house extension can seem daunting, especially with so many things to think about but it’s best to start with figuring out the cost and what you can comfortably afford. Once you’ve got a rough idea of the cost to build an extension, you can move forward with everything else.
Contact Neasden Structural Engineers to ensure your house extension is going to stand the test of time. A structural engineer will look at your architectural drawings and work out the building calculations for your new construction. We can help homeowners in Camden, Chiswick, Ealing, East Finchley, Edgware, Hampstead, Harrow, Kilburn, Neasden, Shepherds Bush, Wembley, Willesden.
Call us on 020 8088 2243 to speak to one of our staff.
