House extensions in Chelsea

The properties we see in Chelsea

Chelsea's stock is older than Fulham's and materially different to build in. The garden squares and the streets off the King's Road are late Georgian and early Victorian stucco-fronted terraces, many Grade II listed, with lath-and-plaster ceilings, solid brick walls, and original joinery that cannot lawfully be replaced. Around World's End there are post-war estates on a completely different construction system. The practical consequence is that standard modern methods are often not permitted: gypsum, cement render and uPVC are all likely to be refused, and the specification has to be breathable and reversible.

Planning in Kensington & Chelsea

RBKC applies Article 4 directions across much of the borough, so permitted development rights that would exist in Fulham simply do not apply here. Listed building consent is needed for internal alterations as well as external ones — including moving a partition or replacing a fireplace. The borough's basement policy is among the most restrictive in London. We establish the designation, the listing grade and any Article 4 direction for the specific address before any design work begins.

What extensions involves

A single-storey rear extension in Fulham costs £3,000–£4,500 per square metre, so a typical 20m² side return is £60,000–£90,000 and takes 14–20 weeks on site. Most Fulham terraces can extend under permitted development, but conservation area status changes that — worth checking before you design anything.

Consider this if

• The kitchen is a narrow galley at the back of the house
• There is a dead side-return alley you never use
• You want the kitchen, dining and living space to be one room
• The family has outgrown the ground floor
• You are choosing between extending and moving
• You want more light into a dark Victorian middle room

What's included

• An honest permitted-development check before you spend money on design
• Architect and structural engineer coordinated, or we work with yours
• Party wall notices served and surveyor appointed
• Foundations, steels, brickwork, roof and glazing
• Full services into the new space — power, lighting, heating, drainage
• Building control inspections and completion certificate

The standard we build to

Built to current Building Regulations Parts A, L and Q, with structural calculations from a chartered engineer and a Party Wall Award where the works are notifiable.

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