Basement conversions in Parsons Green

The properties we see in Parsons Green

The Peterborough Estate — the grid south of New King's Road — is 1890s red-brick terraces known locally as the Lion Houses for the stone lions on their gables. They are large, generously proportioned, and almost identical to one another: the same back addition, the same side return, the same roof pitch. Towards Hurlingham the houses get bigger and detached; towards Sands End the stock shifts to smaller workers' cottages and, along the river, new-build apartment blocks. The Lion Houses are a conservation area, which shapes everything.

Planning in Hammersmith & Fulham

The Peterborough Estate is a designated conservation area, so front elevations, roofs visible from the street and boundary treatments are all controlled, and the lions themselves are protected features. Rear alterations are generally more achievable. Hammersmith and Fulham is the same authority as the rest of Fulham, so the process is familiar to us, but the conservation designation here means permitted development cannot be assumed the way it can a few streets north.

What basements involves

Converting an existing Fulham cellar costs £2,500–£4,000 per square metre; digging a new basement under the house is £4,500–£7,000 per square metre once underpinning and structural work are included. Hammersmith and Fulham restricts basement development, so the planning position matters more here than the build cost.

Consider this if

• There is an existing cellar that is damp and unused
• You have run out of ways to extend up or out
• You want a media room, gym or guest suite
• The house is in a conservation area where extending is restricted
• You need a utility and plant room to free up space above
• The garden is too small to lose to a rear extension

What's included

• Honest feasibility on planning and ground conditions before design
• Structural engineer and underpinning design
• Party wall awards with both adjoining owners
• Full tanking and waterproofing to BS 8102 with a guarantee
• Sump and pump systems with battery backup
• Natural light solutions — lightwells, sun pipes, glazed link

The standard we build to

Waterproofed to BS 8102 with a designed drainage system, and structurally designed by a chartered engineer with party wall awards in place before excavation begins.

For the full write-up on basements — costs, timescales, certification and the questions people ask most — see our basement conversions page. The prices and standards are the same wherever we work.