Core service
House extensions in London
Structural alteration, architectural glazing and finishing works delivered as one package, on constrained London sites.
What we build
Most of the extensions we build are to Victorian, Edwardian and Georgian houses where the new structure has to be threaded into an existing building without disrupting the rest of the home. That work is as much about sequencing, propping and protection as it is about the finished room.
- Rear extensions
- Side-return extensions
- Double-storey extensions
- Outrigger extensions
- Structural alterations and steelwork
- Architectural glazing and rooflights
- Kitchens and internal fit-out
- External landscaping and terraces
- Architectural aluminium doors and windows
- High-end finishes throughout
Structure
Extension work almost always begins with the frame. We install steelwork to the engineer’s design, form new openings in load-bearing walls, and coordinate temporary works with the structural engineer so that the sequence of removal, propping and permanent support is agreed before anything is taken down. At Ceylon Road in Brook Green a cranked beam was installed to open the rear elevation, and large rooflights were craned into position over the completed structure.
Envelope and glazing
The joint between old and new is where extensions fail. We detail brickwork to match existing bonding and mortar, install lead and single-ply roof coverings, and set out glazing so that head heights, reveals and thresholds line through. Architectural aluminium and steel glazing is ordered from survey once the structure is up, not from drawings, so the tolerances are real.
Finishing
Extensions are usually the point at which a kitchen, a utility and a set of external works all land at once. We hold the programme for those trades, coordinate underfloor heating and services within the new floor build-up, and finish the space to the same standard as the rest of the house.
How a project runs
An extension usually starts with drawings from your architect or designer and a design from a structural engineer. Some clients come to us with a full set of drawings, others with little more than an idea; either is fine. We price from the information available, agree the programme with you, and make sure party wall notices are served in good time.
On site the order is broadly the same on every house: protection and strip-out, groundworks and foundations, the new structure and steelwork, the roof and the glazing, then services, plastering, floors, the kitchen and the garden. Building control inspects at each stage, and the house is kept secure and weathertight while the back of it is open.
Our extension projects
Questions we are asked
How long does a house extension take?
It depends on the size and the structure. As a guide, a straightforward single-storey rear extension typically runs three to five months on site, and a side return with a kitchen and external works four to seven. Ceylon Road in Brook Green took two months and Honeywell Road in Battersea three.
Do I need planning permission for an extension?
Not always. Many single-storey rear extensions fall within permitted development, subject to their depth, height and materials, but those rights are often removed in conservation areas or by an Article 4 direction, and anything on a listed building needs consent. Your architect or designer will confirm the route, and a lawful development certificate is worth having even where permission is not needed.
Will I need a party wall agreement?
Usually. New beams bearing on a party wall and foundations dug close to a neighbour's are notifiable under the Party Wall etc. Act 1996, so notices and any awards run alongside the design rather than after it.
Can we stay in the house during the work?
Often, yes, although the kitchen is usually the casualty. We plan a temporary kitchen and a protected route through the house before work starts, and agree with you which rooms stay in use at each stage.