Single storey extension in North London
A single storey extension adds ground-floor space at the rear or side of your home, ideal for a larger kitchen, a dining room or a bright family room. As a guide for North London in 2026, prices are around £50,000-£90,000, and most builds take about 8-12 weeks on site. Kev Construct designs and builds them across Edgware, North London, Barnet, Enfield and Watford, rated 9.67/10 across 50+ verified Checkatrade reviews - and every quote is fixed and itemised.
Recent single-storey extensions
More ground-floor space, without moving home
This is the most popular way to add space to a family home, and for good reason. It opens up the back of the house, connects your living space to the garden, and gives everyone room to breathe, without the cost or upheaval of moving. Kev Construct Ltd has built many of these across North London, and we will make the process calm and clear from the first visit.
What can a single storey extension give you?
Because it sits on the ground floor, a single storey extension is perfect for the rooms your family spends the most time in. It brings in light, opens up the layout, and turns a cramped ground floor into a space that works for daily life.
- A larger kitchen or open-plan kitchen diner where the whole family can cook, eat and gather.
- A bright family or living room that opens onto the garden through bifold or sliding doors.
- A utility room, home office or playroom to take the pressure off the rest of the house.
- More natural light from roof lanterns, skylights and large glazing.
How long does it take, and do I need permission?
Most single storey rear extensions take around 8-12 weeks on site once work starts, weather and materials permitting. Larger builds, or projects with complex glazing and finishes, can take a little longer. We agree a realistic schedule with you before we begin and keep you updated throughout. John runs the site and keeps everything tidy, safe and on track. In most cases you can carry on living at home while we build, because the new structure goes up before we break through into the existing house. Dan and Niko lead the build and take real pride in the finish.
Many single storey rear extensions fall under permitted development, which means you can often build without a full planning application, as long as you stay within the size and height limits. Homes in conservation areas, and some side extensions, usually do need planning permission, and we will tell you honestly where your project stands. Whatever route applies, your extension will still need building regulations approval, which covers structure, insulation, drainage and fire safety. If you build near a shared boundary, the Party Wall Act may also apply. We guide you through all of it. For more, see our planning permission guide.
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 ground floor and garden, and talk through what you want the space to do.
Fixed quotation
Marian prepares a clear, itemised quote in writing with no hidden fees.
Design & planning
We prepare drawings and structural calcs, and handle any planning or building-regs approval.
The build
John, Dan and Niko carry out the work, keep the site tidy and stick to the schedule.
Completion
We hand over your finished room with its certification and workmanship guarantee.
How much does a single storey extension cost?
As a guide for North London in 2026, a single storey extension costs around £50,000-£90,000. Where you land in that range depends on the size, the finishes you choose, the amount of glazing, and any structural work such as steel beams. We give you a fixed, fully itemised written price after a free visit.
Guide ranges for North London, 2026 - not fixed quotes. The biggest single choice is usually the finish: a mid-range kitchen and standard doors keep costs sensible, while a high-end kitchen and large sliding glazing move the figure towards the top. For a full breakdown, see our house extension cost page. We 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.
How big can a single storey extension be under permitted development?
Permitted development sets limits on how far an extension can project from the original rear wall and on its height. For many terraced and semi-detached homes the allowance is generous, and a larger rear extension may be possible under a prior approval process. Rules differ by property and area, so we will check your specific situation and advise honestly before you commit.
Can I have bifold or sliding doors to the garden?
Yes, and they are one of the most popular features we fit. Large glazed doors flood the space with light and connect your kitchen or living room to the garden. We will talk through the options, including bifolds, sliders and roof lanterns, and price them clearly so you can decide what suits your home and your budget.
Will building work disturb the rest of the house?
There will be some noise and dust, that is unavoidable, but we plan the works to keep disruption to a minimum. The new structure is built first, and we only break through into the existing house near the end, so your home stays as normal as possible for as long as possible. John keeps the site clean, safe and organised throughout.
Do I need an architect for a single storey extension?
Usually yes, at least for drawings and building regulations. Good drawings make the build smoother and the quote more accurate. If you already have an architect, we will work alongside them. If not, we can point you to trusted people we have worked with. We are happy to be involved early so the design is practical as well as good looking.
Is a single storey extension worth it compared with moving?
For most families, yes. Once you add up stamp duty, agent fees, legal costs and removals, extending is often the more sensible choice, and it keeps you in the area you love. A well-built single storey extension adds real living space now and can add value to your home. We build to a high standard so it looks right and lasts.
Ready to add the space
your family needs?
Tell us about your extension 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