Fraher Architects has added extra living area to this detached house in South West London by digging down. Sunpipes and rooflights bring natural brightness to the basement. The project’s joinery was completed by Shape
JOCELYN LOW
There are many reasons why people choose to dig down rather than extend horizontally. If you have a large garden in a rural location, then maybe a subterranean level isn’t right for you. But if you live on a tight plot in a built-up area that can’t accommodate a conventional extension, or one that already suffers from overlooking and privacy issues, excavating to create more space could be a surprisingly cost-effective option. Here are the main considerations for digging out a new storey.
Potential complications
The thought of excavating a large hole beneath your property might sound like a recipe for trouble, but the reality is that adding a basement could actually increase the structural stability of your home. “Many historic properties were built on poor ground, with badly designed foundations that aren’t in line with today’s standards,” says Neil Dusheiko from Neil Dusheiko Architects. “Some older dwellings might have suffered from damp and settlement because of their grounding.” Geological surveys and soil tests can be used to establish the conditions beneath the property, which should be fed into your structural engineer’s drawings.
“Working with an experienced engineer is absolutely crucial,” says Elizabeth Webster from Fraher Architects. They should produce a construction method statement detailing the design of the new basement, including the foundations and waterproofing, as well as how work will progress. “If the condition of the building is sensitive, the contractor can set up monitoring stations to check if any movement is taking place due to the works,” adds Neil.