A single-storey extension is a new ground-floor room built onto your house, usually at the rear or side, with its own foundations, walls and roof, creating a bigger kitchen, living space or bedroom without moving home.
If you live in Edmonton and are weighing up a single-storey extension, the starting point is a visit to measure up and talk through what you want, which costs nothing. We cover homes across EN1, N9, N13 and N17, and a typical project of this kind in London lands somewhere in the £45,500–£98,000 bracket, including VAT. The exact figure depends on size, access and the finish you choose.
- Guide price
- £45,500–£98,000 inc VAT
- Time on site
- 10–16 weeks on site
- Postcodes
- EN1, N9, N13, N17 and N18
- Planning rules
- England
- Local area
- Greater London
- Survey
- Free, with a written quote
How much does a single-storey extension cost in Edmonton?
Use the table to gauge the cost of a single-storey extension in Edmonton before we visit. Figures include VAT and are scaled for London, coming out about 30% above the national guide, which gives £45,500–£98,000 overall. After a free survey, you receive a fixed written price.
| Type of job | What it usually involves | Guide in Edmonton |
|---|---|---|
| Small extension (8–12m²) | A modest rear or side extension, such as a utility room or a slightly larger kitchen. | £28,500–£52,000 |
| Typical rear extension (15–25m²) | A kitchen-diner or family room with bifold doors and a rooflight or lantern. | £45,500–£98,000 |
| Large or wrap-around (30m² plus) | A wrap-around or wide rear extension, often with structural steelwork into the house. | £91,000–£169,000 |
The main things that change the figure:
- Floor area, shape and number of corners
- Ground conditions, foundation depth and drains to divert
- Steelwork needed to open into the existing house
- Finishes, kitchen, flooring and heating specification
Scope of the work
- Groundworks, foundations and below-ground drainage
- Cavity walls built and insulated to building regulations
- Flat or pitched roof, with rooflights or a lantern if specified
- Steel beams to open into the existing house
- Plastering, screed floor and internal doors
- Building control inspections and completion certificate
Homes in London
London's housing is dominated by Victorian and Edwardian terraces, often in yellow London stock brick, with Georgian terraces in central districts and mansion blocks across many inner areas. Outer boroughs have large belts of interwar semis, and there are extensive post-war council estates. Many houses have been split into flats, and conservation areas are widespread.
London Clay shrinks and swells with the seasons, and street trees close to houses can contribute to movement, which affects foundation design.
In Edmonton, as elsewhere in London, we take the building's age and construction into account before recommending anything, because both can change what is involved in a single-storey extension.
Planning and building rules in Edmonton
Each UK nation sets its own consent rules, and Edmonton is in England. What follows is a plain summary; we check the specifics for your property with the council before pricing anything.
In England, many single-storey rear extensions are permitted development: typically up to 3 m deep on a semi-detached or terraced house and 4 m on a detached house, no more than 4 m high, and covering no more than half the land around the original house. Larger rear extensions can go through the prior approval process. Side extensions, flats, listed buildings, conservation areas and homes where permitted development rights have been removed need planning permission.
Building Regulations approval is needed for almost every extension, covering foundations, structure, insulation, drainage, ventilation and fire safety. If the work is on or near a shared wall or boundary, the Party Wall etc. Act 1996 may apply.
Rules change and every property is different, so we check the planning history and constraints for your address before we quote.
How does the job run?
Free site survey
It starts with a survey at the property, free of charge. We check condition, access and services, ask how you want the finished result to look, and answer any questions you have about a single-storey extension.
Written quote
You get the price in writing, itemised so you can see where the money goes. As long as the specification stays the same, that is the price you pay for a single-storey extension.
Getting ready
Next comes planning the work itself. We set a start date that suits you, line up the right trades, and make sure any approvals for a single-storey extension are in place before the first day on site.
On site to finish
Our trades complete a single-storey extension while your point of contact keeps you updated. When everything is finished, we clear the site, take away waste and go through the result with you before handover.
What you can expect from us
Frequently asked questions
How much will a single-storey extension cost in Edmonton?
As a guide, expect to pay £45,500–£98,000 including VAT for a single-storey extension in Edmonton. That range is adjusted for London, which runs about 30% above the national guide. Where your project lands depends on size, materials, access and the condition of what is already there. We confirm a fixed price in writing after a free survey of your home.
Do I need an architect for an extension?
You need proper drawings for an extension, but not always a full architect service. A designer or architectural technician can produce planning and building regulations drawings, and a structural engineer provides beam and foundation calculations. If you already have drawings, we price from them. If not, we can arrange the drawings and calculations as part of the project so everything is coordinated from the start.
How long does a single-storey extension take to build?
A single-storey extension usually takes 10–16 weeks on site, from digging foundations to final plastering. Bad weather, deep foundations or a complex roof can add time. Before work starts, allow several weeks for drawings, structural calculations and building control approval, and longer if planning permission is needed. We give you a stage-by-stage programme with your quote so you know what happens each week.
What is the Party Wall Act and does it apply to me?
The Party Wall etc. Act 1996 applies in England and Wales only. In England and Wales, it requires you to give notice to neighbours before certain work on or near a shared wall, such as digging foundations within 3m of their building and deeper than its footings. Neighbours can agree or appoint a surveyor. Scotland and Northern Ireland have no equivalent Act, though general rights still apply. We identify whether notices are needed during the survey.
Which postcodes in Edmonton do you cover?
We cover EN1, N9, N13 and N17, along with the rest of London. If your postcode is not listed, get in touch anyway: our coverage is UK-wide, and we can usually arrange a survey wherever you live. Enter your postcode in the guide-price tool or contact form and we will confirm.
Near Edmonton
Coverage for Edmonton spans EN1, N9, N13 and N17. Close by, Tottenham, Enfield Town and Chingford are covered too, and the rest of our UK-wide area follows the same survey-then-quote process from start to finish.