Sunbury-on-Thames, Surrey
Glazed rear extension in Sunbury-on-Thames
Full-height glass, slim frames and big rooflights for the most open rear room. If you live in Sunbury-on-Thames 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.
Sunbury-on-Thames is covered from our Surrey round, including KT12, TW16 and TW17. A wide sliding door with one long rooflight, rather than a fully glazed roof, keeps a glass-led extension usable in summer.
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 Sunbury-on-Thames?
For Sunbury-on-Thames we work from the South East England rate: £3,140–£5,380 per square metre of new floor, including VAT, standard specification. 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 Sunbury-on-Thames?
Planning for a glazed rear extension in Sunbury-on-Thames 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 Sunbury-on-Thames like to extend?
Sunbury-on-Thames has a mix of Victorian terraces near the centre and larger Edwardian and inter-war houses further out. Clay soils across much of the South East mean deeper foundations near trees, which we plan for at the survey.
How a glazed rear extension in Sunbury-on-Thames 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.
Options and costs
We draw layout options and price each one, so the budget shapes the design rather than surprising you later.
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 Sunbury-on-Thames
Close by, we work in Walton-on-Thames, about 1.2 miles away, and Shepperton, about 1.5 miles away.
- Glazed rear extension in Walton-on-Thames
- Glazed rear extension in Shepperton
- Glazed rear extension in West Molesey
- Glazed rear extension in Hampton
- Glazed rear extension in Hanworth
Other work in Sunbury-on-Thames:
FAQ
Glazed rear extension questions in Sunbury-on-Thames
Do you handle building control in Sunbury-on-Thames?
Yes. We apply to the council or a registered building control approver and hand over the completion certificate.
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.
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.
What postcode areas do you cover around Sunbury-on-Thames?
Including KT12, TW16 and TW17, and the surrounding Surrey area.
How much does a glazed rear extension cost in Sunbury-on-Thames?
As a guide, £3,140–£5,380 per square metre including VAT for a standard specification. For example, 3 m wide × 4 m deep (12 m²): about £37,500–£64,500 at that rate. Your written price follows the survey.