Biggin Hill, Kent
Glazed rear extension in Biggin Hill
Glazed rear extension in Biggin Hill: full-height glass, slim frames and big rooflights for the most open rear room. We measure the house, show you what the rules allow, price it in writing and build it.
We cover Biggin Hill (TN16) as part of our Kent work. Glass-led rear extensions in Biggin Hill 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 Biggin Hill?
Guide prices for a glazed rear extension in Biggin Hill start from our South East England rate of £3,140–£5,380 per square metre, including VAT. South East prices run above our West Midlands baseline, mainly on labour rates and clay-soil foundations.
| Size | Guide price inc VAT |
|---|---|
| 3 m wide × 4 m deep (12 m²) | £37,500–£64,500 |
| 4 m wide × 6 m deep (24 m²) | £75,500–£129,000 |
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 Biggin Hill?
Planning for a glazed rear extension in Biggin Hill follows the English householder rules.
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 Biggin Hill like to extend?
Around Biggin Hill the housing ranges from inter-war semis to 1960s and 1970s estates with good-sized gardens. Many of the newer estates had permitted development rights removed by condition, so we check the planning history before anything is drawn.
How a glazed rear extension in Biggin Hill 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.
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 Biggin Hill
We also build glazed and glass-box rear extensions in nearby Oxted (4.3 miles) and West Wickham (4.3 miles).
- Glazed rear extension in Oxted
- Glazed rear extension in West Wickham
- Glazed rear extension in Orpington
- Glazed rear extension in Chelsfield
- Glazed rear extension in Sanderstead
Other work in Biggin Hill:
FAQ
Glazed rear extension questions in Biggin Hill
What postcode areas do you cover around Biggin Hill?
Including TN16, and the surrounding Kent area.
Is the site visit in Biggin Hill free?
Yes. We visit, measure up and talk through the options with no cost and no obligation.
Does glass need planning permission?
The same rules apply as any rear extension; glass does not change the depth or height limits.
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.
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 Biggin Hill?
Most single-storey rear extensions take 10 to 16 weeks on site and two-storey extensions 16 to 26 weeks, after design and approvals.