Going underground to extend your home

IT seems we Britons are spending more and more time down under – in our basements, that is. No longer storerooms for junk, these subterranean spaces are increasingly becoming part of our homes, and their uses increasingly varied, with owners busy moulding cinema rooms, saunas, gyms, even golf simulator rooms.

And that’s just in your average family home – head downstairs in the homes of the super-wealthy and the basements are outrageously imaginative. Tennis and squash courts, swimming pools, shooting alleys, climbing walls and mini-spas are not uncommon. The further out from London you go, the more inventive homeowners seem to become: one agent from Quintessentially Estates viewed a property in Surrey with a fully kitted-out basement go-karting track for the owner and his sons to enjoy. Knight Frank agency is currently selling a home in Devon for £3.5m where its lower-ground floor has a 32-seat cinema, bowling alley, bar and billiards room.

“I’ve noticed that the way people are using basements has become a lot more imaginative,” says Jo Eccles, director of buying agency Sourcing Property. “It used to be that you would see a cinema room down there, if the homeowners were really adventurous, but now anything goes. I recently viewed a house in Hampstead that had a huge basement that included an indoor pool, a bar and a beautician’s room, complete with a treatment table and hair salon.”

Hugo Tugman, founder of Architect Your Home, points out that the art of a successful basement is “to make it as little basement-like as possible. So by adding lightwells, which obviously provide lots of daylight, you can make the rooms below ground as pleasant as any above, and even have sitting rooms and kitchens down there.”

If your budget doesn’t stretch to adding lots of light, he suggests the best approach is to choose uses that make the best of the darkness – saunas or cinema rooms, for example.


Often families want more practical uses for their space than a go-karting track or ten-pin bowling alley, of course. Tugman gives the example of a recent basement he designed in a home in leafy Barnes, south west London, which also came with a garage.

“The owner wanted to create a sitting room in the basement but it wasn’t possible to get much light down there, so I had to explain to him that it wouldn’t be like a normal sitting room and perhaps it was best to rethink. In the end, we converted the garage, which was on the ground floor and had lots of windows, into the sitting room, and put a garage – with a ramp – in the basement. It all worked extremely well in the end.”

Anyone thinking of adding a basement to their home should be aware they aren’t cheap, costing roughly double the price of a side extension – the excavating and supporting beams to keep the house from toppling over while the basement is being dug out makes it one of the most expensive home improvement projects you can invest in.

Julie Hindle, of the London Basement Company, says that the basement conversions the company works on typically cost from £300 to £350 per square foot. The starting prices for the average Victorian house to have its basement excavated to a size of 600 sq ft would be £180,000 – for this you would get two or three rooms. It costs less to convert an existing cellar, or if the space is smaller.

“Lots of people use their basements for living areas,” Hindle says. “The basements we’ve converted have been made into living rooms, playrooms, cinema rooms, gyms or swimming pools. The majority of our customers do get planning permission, but if you live in a conservation area it can make it more difficult.”

John Harrison-Church, who is a full-time dad and part-time property developer, has recently built from scratch a four-bed home in Teddington, close to Hampton Court, with large underground rooms housing the home’s main kitchen and sitting room.

“It’s a huge, open-plan area with a kitchen, dining and sitting area and lightwell at the end,” says Harrison-Church, who shares the home with his wife, marketing director Claire, and their two children, 15-year-old George and 13-year-old Robyn.

“At first we didn’t think we’d get much light down here and would have to put in a sauna or something like that. But then we employed Architect Your Home and found we could have all this extra living space. It’s made a huge difference to us as a family – having an extra living room and dining room means we’re not on top of each other. When friends come round for the first time and I show them downstairs, they can’t quite believe they are in a basement at all.”