Cockfosters, Greater London
Side return extension in Cockfosters
Thinking about a side return extension in Cockfosters? Infilling the narrow passage beside a Victorian or Edwardian back addition. Our team handles the drawings, the planning route and the build, and your contract is with one company throughout.
Cockfosters is covered from our Greater London round, including EN4, N14 and N20. Side return projects in Cockfosters usually start with a drainage survey of the side passage.
Book a free site visit
Tell us about the house and we'll call to arrange a free, no-obligation visit.
How much does a side return extension cost in Cockfosters?
Guide prices for a side return extension in Cockfosters start from our London rate of £2,990–£4,940 per square metre, including VAT. London prices sit at the top of our range because of labour rates, access through the house, parking suspensions and skip licences.
| Size | Guide price inc VAT |
|---|---|
| 2 m wide × 6 m deep (12 m²) | £36,000–£59,500 |
| 2.5 m wide × 7 m deep (17.5 m²) | £52,500–£86,500 |
These are guide ranges; the written quote after the survey is the figure that counts.
Do you need planning permission for a side return extension in Cockfosters?
Planning for a side return extension in Cockfosters follows the English householder rules.
Side return infills and the side leg of a wraparound are treated as side extensions in England: single-storey, no more than 4 metres high and no wider than half the original house. They are not permitted development in conservation areas, National Parks or National Landscapes, and a joined wraparound often needs a planning application because the side and rear rules apply together.
The Party Wall etc. Act 1996 applies in England: you serve notice two months before work to a shared wall, and one month before digging foundations within 3 metres (or 6 metres for deeper foundations) of a neighbour's building. Neighbours can agree in writing; if they dissent, surveyors agree an award.
Conservation areas, National Parks, National Landscapes and the Broads restrict permitted development, and listed buildings always need listed building consent. We check your house's planning history and any conservation area before drawing, so the route is clear before you spend on plans.
What are homes in Cockfosters like to extend?
Cockfosters is mostly 1930s semis, short terraces and post-war houses, so full-width single-storey and two-storey rear extensions are realistic on many plots. Some later estates had permitted development rights removed by condition, so we check the planning history first.
How a side return extension in Cockfosters comes together
Free site visit
We measure the house and garden, look at the back wall, drainage and boundaries, and talk through what you want from the space.
Drawings and budget
Floor plans and elevations for the options, each with a guide price.
Paperwork handled
Planning, prior approval or permitted development, Building Regulations approval, structural design and party wall notices are all handled by us.
Written price, then build
Once the design and approvals are in place, you get a fixed written price and programme, and we build through to sign-off.
Side return extensions near Cockfosters
Neighbouring places we cover include East Barnet (0.6 miles) and New Barnet (1.2 miles).
- Side return extension in East Barnet
- Side return extension in New Barnet
- Side return extension in Hadley Wood
- Side return extension in Barnet
- Side return extension in Totteridge
Other work in Cockfosters:
FAQ
Side return extension questions in Cockfosters
Can I get a price without a visit?
Our online guide-price tool gives a range in a couple of minutes. A written price needs a survey.
Do I need a party wall agreement?
In England, usually yes if the extension is on or near a shared boundary or the foundations are close to a neighbour's building. We serve the notices.
Glass roof or solid roof with rooflights?
A glass roof gives the most light; a solid roof with long rooflights is warmer and quieter in rain. Both work.
Can I live at home while the extension is built?
Usually yes. Most of the work is outside until the back wall is opened near the end, and that stage is screened off.
Is the site visit in Cockfosters free?
Yes. We visit, measure up and talk through the options with no cost and no obligation.
Do you handle building control in Cockfosters?
Yes. We apply to the council or a registered building control approver and hand over the completion certificate.