This beginner’s guide to building an extension covers everything you need to know before you start. From what to design to getting plans passed, from working out your budget to the trades and build – it pays to know what building an extension involves.
After all, you’ll be investing financially and emotionally in building an extension so you want the build to go as smoothly as it can do! So let us guide you through the things you need to know.
Depending where you are in the UK, for a straightforward extension you should allow around £1,000–£2,000/m2. But, the cost of your extension will all come down to a number of factors, including size, specification and location.
Building a single-story extension will cost the following per/m2:
- Basic quality: £1,000 to £1,680
- Good quality: £1,680 to £1,920
- Excellent quality: £1,920 to £2,160
Building a two-storey extension will not cost much more per square metre because, aside from the extra interior fixtures and finishes, you are only adding walls and floor joists — a roof and foundations are required whether your extension is single or two storey.