House extensions in Fulham
Rear, side-return and wrap-around extensions that open up a Victorian ground floor.
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.
Planning position
Often permitted development, but not in a conservation area or on a flat. Party wall agreement almost always needed.
| Guide range | £3,000/m² |
| Typical duration | 14–20 weeks on site |
| Planning | Hammersmith & Fulham |
Guide ranges for budgeting, excluding VAT and professional fees. We quote a fixed price after a site visit.
Get a fixed priceExtensions — what people ask
How much does an extension cost in Fulham?
£3,000 to £4,500 per square metre excluding VAT for a good-quality single-storey rear or side-return extension. A typical Fulham side return of 18–22m² therefore lands between £60,000 and £90,000 for the shell and services, before the kitchen. Double-storey costs less per square metre because you reuse the foundations and roof — usually £2,800 to £4,000.
Read the full answerWhat is a side return extension?
The side return is the narrow strip of land running alongside the back addition of a Victorian terrace, usually a metre or two wide and almost always wasted. Filling it in widens the rear of the house across its full width, which turns a dark galley kitchen into a proper family room. It is the single most common extension in Fulham because almost every terrace here has one.
Read the full answerDo I need planning permission for an extension in Fulham?
Not always. Single-storey rear extensions up to 3m on a terrace (or 6m under the larger home extension scheme, with prior approval) can fall under permitted development. But Hammersmith and Fulham has several conservation areas where those rights are restricted or removed, and flats never have permitted development rights at all. We check your specific address before any design work starts.
Read the full answerHow long does an extension take to build?
14 to 20 weeks on site for a single-storey rear or side return. Add 8 to 12 weeks before that for design, structural calculations and either a planning decision or a lawful development certificate, plus two months for party wall notices to run their course. Realistically, from first conversation to finished room is nine to twelve months.
Read the full answerExtensions across south west London
The housing stock and the planning authority change what is achievable. Each area page covers what is specific to it.
Planning extensions in Fulham?
Tell us what you have in mind and we will come back with an honest view on cost, timescale and what is achievable at your address.