Thornbury, Bristol and South Gloucestershire
Glazed rear extension in Thornbury
Thinking about a glazed rear extension in Thornbury? Full-height glass, slim frames and big rooflights for the most open rear room. Our team handles the drawings, the planning route and the build, and your contract is with one company throughout.
Thornbury sits in Bristol and South Gloucestershire, with postcode districts including BS35. If your garden in Thornbury faces south, expect us to talk about overhangs and solar-control glass before frame colours.
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 Thornbury?
A glazed rear extension in Thornbury is priced at £2,910–£4,990 per square metre including VAT as a guide, before kitchen fit-out and fees. South West prices run slightly above our West Midlands baseline; natural stone to match the house is the main variable.
| Size | Guide price inc VAT |
|---|---|
| 3 m wide × 4 m deep (12 m²) | £35,000–£60,000 |
| 4 m wide × 6 m deep (24 m²) | £70,000–£120,000 |
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 Thornbury?
Planning for a glazed rear extension in Thornbury 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. 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 Thornbury like to extend?
Stone-built and rendered houses are common around Thornbury, so matching the walling is a design decision in its own right: natural stone, reconstituted stone or a render finish across old and new.
How a glazed rear extension in Thornbury 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.
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.
Glazed rear extensions near Thornbury
Neighbouring places we cover include Stoke Gifford (6.4 miles) and Yate (6.4 miles).
- Glazed rear extension in Stoke Gifford
- Glazed rear extension in Yate
- Glazed rear extension in Chepstow
- Glazed rear extension in Mangotsfield
- Glazed rear extension in Dursley
Other work in Thornbury:
FAQ
Glazed rear extension questions in Thornbury
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 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.
Can I have a level threshold?
Yes, with a drainage channel outside the doors and the slab set to the patio level.
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.
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.
How much does a glazed rear extension cost in Thornbury?
As a guide, £2,910–£4,990 per square metre including VAT for a standard specification. For example, 3 m wide × 4 m deep (12 m²): about £35,000–£60,000 at that rate. Your written price follows the survey.