Harlesden, Greater London
Glazed rear extension in Harlesden
Full-height glass, slim frames and big rooflights for the most open rear room. We design, get the approvals for and build glazed and glass-box rear extensions in Harlesden and the surrounding area, with one contract from the first survey to building control sign-off.
Harlesden is covered from our Greater London round, including NW2, NW10 and W10. Glass-led rear extensions in Harlesden 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 Harlesden?
A glazed rear extension in Harlesden is priced at £3,640–£6,240 per square metre including VAT as a guide, before kitchen fit-out and fees. 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 |
Your written price follows a measured survey and an agreed design, so it reflects your house, not an average.
Do you need planning permission for a glazed rear extension in Harlesden?
Planning for a glazed rear extension in Harlesden follows the English householder rules.
In England a single-storey rear extension can often be built under permitted development: up to 3 metres beyond the original rear wall of an attached house, or 4 metres on a detached house, no higher than 4 metres, with eaves no higher than 3 metres if any part is 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 Harlesden like to extend?
Period terraces in Harlesden sit alongside flats, and the difference matters: houses usually keep permitted development rights, while flats and maisonettes need planning permission for any rear extension.
How a glazed rear extension in Harlesden 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.
Design and guide price
Two or three layout options with a guide price for each, so you choose the design knowing what it costs.
Approvals
Permitted development check, prior approval or planning application, then Building Regulations drawings and structural calculations, plus party wall notices where they apply.
Fixed price and build
A written price for the agreed design, a start date and a named contact through the build, ending with the building control completion certificate.
Glazed rear extensions near Harlesden
From Harlesden, the nearest places we also cover are Willesden (0.8 miles) and Kensal Green (1.2 miles).
- Glazed rear extension in Willesden
- Glazed rear extension in Kensal Green
- Glazed rear extension in Queen's Park
- Glazed rear extension in Cricklewood
- Glazed rear extension in Wembley
Other work in Harlesden:
FAQ
Glazed rear extension questions in Harlesden
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.
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.
Will a glass extension be too hot?
Not if it is designed for its orientation, with solar-control glass, shading and ventilation.
Can you match the brick or stone on my Harlesden house?
We source the closest match and show you samples before ordering; reclaimed materials are often the best match on older houses.
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.
What postcode areas do you cover around Harlesden?
Including NW2, NW10 and W10, and the surrounding Greater London area.