DOT How Much Value Does an Extension or Loft Conversion Add?
What the research says about adding space, bedrooms and bathrooms, what each project costs with us, and our honest view: most of our customers extend for the home they want to stay in, not to sell.
Short answer: Yes, usually. Nationwide Building Society’s research found a loft conversion or extension that adds a double bedroom and a bathroom could add around 20% to a three-bed house, and every 10% more floor space adds about 5%. Adding a bedroom or bathroom matters more than floor space alone.
Which home improvements add the most value?
Loft conversion or extension adding a double bedroom and bathroom
Turns a three-bed, one-bathroom house into a four-bed with two bathrooms. With us, a dormer or hip-to-gable loft conversion is usually £32,000–£65,000, plus an estimated £6,000–£15,000 for an en-suite.
Adding a double-bedroom-sized space
Adding a room the size of a typical double bedroom to a two-bed house. A single-storey extension with us is usually £30,000–£65,000.
A second bathroom
Adding another bathroom, on top of any extra space.
More floor space in general
For every 10% you add to the floor area, Nationwide found the value rose by about 5%.
Source: Nationwide Building Society research, reported April 2016. These are national averages from 2016, so treat them as a rough guide. A local estate agent can tell you what buyers pay for an extra bedroom in your street. Prices shown are DOT prices plus VAT.
What makes the biggest difference to value?
The single biggest lever is usually bedroom count — a project that pushes a house into a higher bedroom bracket (e.g. 3-bed to 4-bed) tends to add more value than one that simply adds square footage within the same bracket.
Should you extend just to add value?
Honestly, most of our customers don’t extend to sell. They do it because it’s their forever home, or the house they want to bring their kids up in, and they need more space to live in now. That’s why we’ve never had before-and-after valuations from our own jobs.
What we can say is that a bigger house, with more bedrooms or more living space, is only going to help when you do come to sell. Just make sure it’s signed off by Building Control, because a buyer’s solicitor will ask for the completion certificate. If resale value is your main reason, talk to a local estate agent first about what buyers in your area pay for.
Not sure which project makes sense for you?
We’ll talk through cost, value, and what actually suits your property — free of charge.