In London, and especially in Chelsea, Fulham and South Kensington, the only realistic way to add floor area is to build a basement. Most London houses can take one, and whether there is an existing cellar or not makes very little difference.
Most clients take the basement out to the full footprint of the house, because the expensive part is the underpinning and the waterproofing rather than the last few square feet. The fit out is on top of the shell, and depends entirely on the specification of the floors, the bathrooms and the fittings. Our published rates for basement work are on the cost calculator.
A complete basement project takes roughly eight to nine months. The digging and underpinning is four to five months of that, and the fit out another four.
A basement in West London adds a whole floor to a house that could not be extended any other way, and floor area is what a London property is valued on.
NU Projects has done a great deal of basement work in West London. We have recently started a new project in Fulham. The terrace property will get a full home refurbishment from top to bottom, a loft conversion, a kitchen side return extension and a basement fit-out. The property has an existing cellar with low head height, so our job is to drop the floor by a metre to give the room a usable ceiling.
There is more on this project on our YouTube channel. If you are thinking about a basement of your own, tell us about the house, or call the studio on 020 7731 6841.
Published 19 March 2020. Written by the NU Projects studio, edited since for house style and accuracy.