East Barnet, Greater London
Glazed rear extension in East Barnet
Full-height glass, slim frames and big rooflights for the most open rear room. If you live in East Barnet and want to know what a glazed rear extension would cost and whether it needs planning, start with the online guide price or a free site visit.
We cover East Barnet (EN4, EN5 and N20) as part of our Greater London work. Glass-led rear extensions in East Barnet are planned around which way the garden faces, because that decides the glass specification.
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 glazed rear extension cost in East Barnet?
Guide prices for a glazed rear extension in East Barnet start from our London rate of £3,640–£6,240 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 |
|---|---|
| 3 m wide × 4 m deep (12 m²) | £43,500–£75,000 |
| 4 m wide × 6 m deep (24 m²) | £87,500–£150,000 |
Ground conditions, glazing, the roof and how far the house is opened up move the final figure within the range.
Do you need planning permission for a glazed rear extension in East Barnet?
Here is how the rules in England apply to a glazed rear extension in East Barnet.
English permitted development (Class A) allows a single-storey rear extension of 3 metres on a terraced or semi-detached house and 4 metres on a detached one, measured from the original house, with a maximum height of 4 metres and eaves of no more than 3 metres within 2 metres of a boundary.
New fabric must meet Approved Document L (2021 edition incorporating 2023 amendments): walls 0.18, roof 0.15 and floor 0.18 W/m²K, windows 1.4 W/m²K or Band B. Under the simple route, new windows, doors and rooflights should not exceed 25% of the extension floor area plus any openings removed; more glass is possible with a whole-house calculation.
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 East Barnet like to extend?
East Barnet 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 glazed rear extension in East Barnet comes together
Survey visit
We visit free of charge, measure up, check access, drainage and neighbours' extensions, and note what you want the room to do.
Design and guide price
Two or three layout options with a guide price for each, so you choose the design knowing what it costs.
Planning and regulations
We take the design through the right planning route, then produce the construction drawings and engineer's calculations for building control.
Build and sign-off
We build to the approved drawings with regular updates, then hand over the building control completion certificate and any guarantees from suppliers.
Glazed rear extensions near East Barnet
Neighbouring places we cover include Cockfosters (0.6 miles) and New Barnet (0.6 miles).
- Glazed rear extension in Cockfosters
- Glazed rear extension in New Barnet
- Glazed rear extension in Hadley Wood
- Glazed rear extension in Barnet
- Glazed rear extension in Totteridge
Other work in East Barnet:
FAQ
Glazed rear extension questions in East Barnet
Who will build my extension?
Vetted building teams working under contract to us. Your contract is with S&K Property Investments and Improvement Ltd for the design and the build.
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.
Sliding or bifold doors?
Sliders give bigger panes and slimmer sightlines; bifolds open the whole width. Our guide compares them.
Is the site visit in East Barnet free?
Yes. We visit, measure up and talk through the options with no cost and no obligation.
Will I need a structural engineer?
Yes for the beam over the new opening and usually the foundations; we arrange them and their calculations go to building control.
How long does a rear extension take to build in East Barnet?
Most single-storey rear extensions take 10 to 16 weeks on site and two-storey extensions 16 to 26 weeks, after design and approvals.