Billericay, Essex
Glazed rear extension in Billericay
Full-height glass, slim frames and big rooflights for the most open rear room. If you live in Billericay 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.
Billericay and its postcode districts CM12 are part of our Essex coverage. Glass-led rear extensions in Billericay 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 Billericay?
In Billericay, our guide for a glazed rear extension is £2,970–£5,090 per square metre including VAT for a standard specification. East of England prices run slightly above our West Midlands baseline; clay soils near trees are the main foundation variable.
| Size | Guide price inc VAT |
|---|---|
| 3 m wide × 4 m deep (12 m²) | £35,500–£61,000 |
| 4 m wide × 6 m deep (24 m²) | £71,000–£122,000 |
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 Billericay?
The planning route for a glazed rear extension in Billericay is set by England's householder rules and your council.
Under England's householder permitted development rules you can usually add 3 metres at the back of an attached house, or 4 metres on a detached house, without a planning application, as long as the extension stays under 4 metres high and its eaves stay under 3 metres where it 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. At the first visit we measure what is there now and tell you which route fits: permitted development, prior approval or a planning application.
What are homes in Billericay like to extend?
Post-war semis and newer estates are typical of Billericay, and many have room for a full-width extension. Shrinkable clay is common in the East of England, so foundations near trees and hedges are designed to NHBC-style depth guidance.
How a glazed rear extension in Billericay comes together
Look round and measure
A free visit to see the back of the house, measure it, check the drains and boundaries and hear what you need.
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.
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.
Glazed rear extensions near Billericay
Neighbouring places we cover include Basildon (4.5 miles) and Wickford (4.6 miles).
- Glazed rear extension in Basildon
- Glazed rear extension in Wickford
- Glazed rear extension in Brentwood
- Glazed rear extension in Pitsea
- Glazed rear extension in Stanford-le-Hope
Other work in Billericay:
FAQ
Glazed rear extension questions in Billericay
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.
How long does a rear extension take to build in Billericay?
Most single-storey rear extensions take 10 to 16 weeks on site and two-storey extensions 16 to 26 weeks, after design and approvals.
Is there a limit on how much glass I can have?
In England the simple rule is 25% of the floor area plus openings removed; more is allowed with a calculation showing the house still meets Part L.
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 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.
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.