House extensions in North London
A house extension gives your family the extra room you have outgrown without the cost, stress and upheaval of moving home. Kev Construct Ltd designs and builds single-storey, double-storey, rear, side return and kitchen extensions across North London, with clear quotes and finishes you will be proud of - the space you actually need, in the home you already love.
Recent house extensions in North London
Add the space you need, and keep the home you love
Extending is usually cheaper and less disruptive than moving, and it adds space that is designed around how your family really lives. Once you add up stamp duty, estate agent fees, legal costs and removals, a well-planned extension often makes more sense, keeps you in the area you love, and can add real value to your home.
We build extensions for one simple reason: to give you more room to live. That might be an open-plan kitchen diner where everyone gathers, a bright living space that opens onto the garden, an extra bedroom and bathroom upstairs, or a quiet home office. You know your home better than anyone - you love the street, the neighbours and the school run, but the kitchen is too small and the family has grown. An extension lets you stay exactly where you are and add the space you actually need.
What types of house extension do we build?
We build the full range of home extensions, so you can pick the right approach for your house, your garden and your budget. Each option adds space in a different way, and we will help you choose the one that suits your home and how your family lives day to day.
Single-storey rear
Extra ground-floor space at the rear or side, ideal for a bigger kitchen, dining room or family room. Guide: £50,000-£90,000.
Maximum spaceDouble-storey
Adds space upstairs and down in one build, often a larger kitchen below and an extra bedroom or bathroom above. Guide: £70,000-£130,000.
Period terracesSide-return
Fills in the wasted side alley to create wide, bright, open-plan living at the back of the house. Guide: £55,000-£95,000.
Heart of the homeKitchen extension
Designed around cooking, eating and family time, usually as a single-storey rear or side return build. Guide: from £50,000.
One team, from first drawing to final coat of paint
We handle the whole project with one team you can talk to throughout. We will tell you honestly whether your project is likely to fall under permitted development or need planning permission, point you to trusted architects and engineers for drawings and calculations, and work alongside your own team if you already have one. Almost every extension needs building regulations approval covering structure, insulation, drainage and fire safety, and where you build near a boundary the Party Wall Act may apply - we guide you through all of it and work with building control.
Because it is all delivered by Kev Construct rather than a string of separate trades, there are no gaps for things to fall through and no finger-pointing if something needs sorting. John runs our sites and keeps them tidy, safe and moving to plan. Dan and Niko lead the build itself, from the brickwork and plastering to the moment we hand your new space back to you clean and ready to use. Marian sets the quote out clearly in writing so you know the full cost before we start, with no hidden fees, backed by the £1,000 Checkatrade Guarantee.
Room to breathe, downstairs and up
A rear or side-return extension opens the ground floor into the bright, open-plan kitchen-diner most North London families are after - and a double-storey adds bedrooms above. We design and build it to flow naturally with your existing home.
A simple, predictable process.
You always know what happens next, who's on site, and exactly what it costs.
Free home visit
We come to you, look at your home and garden, and talk through what you want the new space to do.
Fixed quotation
Marian prepares a clear, itemised quote in writing with no hidden fees.
Design & planning
We point you to trusted architects and engineers, and handle any planning, building-regs or party wall matters.
The build
John runs the site while Dan and Niko carry out the work, keep it tidy and stick to the schedule.
Completion
We hand over your finished space with its certification and workmanship guarantee.
How much does a house extension cost in North London?
As a guide for North London in 2026, a single-storey extension costs around £50,000-£90,000, a side return around £55,000-£95,000, and a double-storey around £70,000-£130,000. Your final price depends on size, spec and site conditions. Every quote from us is fixed and fully itemised, with no hidden fees.
Guide ranges for North London, 2026 - not fixed quotes. Ground conditions, finishes, glazing and structural work all move the figure up or down. We quote every project individually and put the final figure in writing before any work begins.
What our customers say.
“John and the whole crew were a pleasure to work with. Fast, great communication, finished on time and to a high quality.”
“Dan and Niko put real care into the work; Marian set everything out clearly with no hidden fees. They went above and beyond.”
“We're an architecture practice and have worked with Kev Construct for years. Reliable, trustworthy, excellent finishes.”
Good to know.
Do I need planning permission for a house extension?
Not always. Many single storey rear extensions fall under permitted development, which means you can build without a full planning application, as long as you stay within the size limits. Double-storey, front and side extensions, and homes in conservation areas, usually do need planning permission. We will tell you honestly where your project stands and can help with the paperwork.
Will you handle building regulations and the Party Wall Act?
Yes. Almost every extension needs building regulations approval, which covers structure, insulation, drainage and fire safety, and this is separate from planning. If you build near or on a shared boundary with a neighbour, the Party Wall Act may also apply. We guide you through both, work with building control, and make sure everything is done correctly and signed off.
Can we stay in the house while you build?
In most cases, yes. A rear or side extension can usually be built while you carry on living at home, because the new structure goes up before we break through into the existing house. There will be some noise and dust, and the kitchen may be out of action for a spell, but John plans the works to keep disruption to a minimum and keeps the site clean and safe.
How much value does an extension add to my home?
A well-designed extension can add real value, especially when it creates a larger kitchen, an extra bedroom or a bright open-plan living space that buyers in North London look for. More importantly, it gives you the space to enjoy your home now. We build to a high standard so your extension looks right, feels right and stands the test of time.
Ready to add the space
your family needs?
Tell us about your home and we'll arrange a free home visit. You'll get a clear, fixed price in writing - with no pressure and no hidden fees.
- Free home visit & survey
- Fixed price in writing - no surprises
- Local Edgware team · rated 9.67/10 on Checkatrade
Prefer to talk? 07838 662 225