Building
House extensions in London
Rear, side return and double-storey extensions — from the foundations to the kitchen floor, managed by one team.
What we do
Extensions, done properly.
An extension involves more trades than almost any other home project: groundwork, drainage, brickwork, steels, roofing, windows and doors, plumbing, electrics, plastering, flooring and decorating. The more of that one team can handle, the fewer gaps there are for things to fall through.
Swift Fix carries out all of it. We coordinate structural input, Building Control and Party Wall matters, get the shell weathertight early, and keep you updated as the work moves from stage to stage.
Single-storey rear
Kitchen-living spaces opening onto the garden.
Side return
Using the side alley to widen narrow terrace kitchens.
Wraparound
Side return and rear combined for maximum space.
Double-storey
Extra space downstairs plus bedrooms or a bathroom above.
Structure
Foundations, steels and lintels to the engineer’s design.
Fit-out
Kitchen, flooring, plastering and decorating to finish.
Planning permission, Building Control and Party Walls
Many single-storey rear and side extensions fall under permitted development, provided they stay within limits on depth, height and eaves. Wraparounds, double-storey additions and properties in conservation areas usually need planning permission. We will help you establish which applies before you spend money on drawings.
All extensions need Building Regulations approval covering structure, fire safety, insulation, drainage and electrics. If you share a wall with a neighbour, the Party Wall etc. Act 1996 may apply, and notices should be served early to protect the programme.
Living at home during the build
Most people stay at home while their extension is built. We phase the work so that essentials remain usable, protect routes through the house, and agree temporary arrangements — such as a temporary sink or cooking area — before the kitchen is disconnected.
What customers say
“We are thrilled with our home extension from SwiftFix. From start to finish, the entire process was straightforward and stress-free. Communication was excellent, and the team were diligent and attentive to our needs.” — Helen R, Essex
Our work
Photographed on our own jobs.
Every photo on this page is genuine Swift Fix work. Tap any image to see it larger.
Do I need planning permission for an extension?
Sometimes. Many rear and side return extensions fall under permitted development if they meet the rules. We confirm what applies before you spend on drawings.
How long does an extension take?
A single-storey rear extension typically takes 8–12 weeks depending on structure and finishes. Double-storey or complex structural work takes longer; you get a programme with your quote.
Can we live at home during the build?
Usually, yes. We phase the work, protect your home and agree temporary facilities in advance.
Do you deal with Party Wall matters?
We advise on the Party Wall etc. Act and can arrange surveyors where needed. Notices are best served early to keep the programme on track.
One team, the next trade
Every extension ends with a kitchen, flooring and decoration — and we do those too.
Free quotes · No obligation
Planning your next project?
Speak to Swift Fix about your building, roofing or refurbishment project. Free, no-obligation quotes across London and Kent.