Devon
Glazed and glass-box rear extensions in Devon
Full-height glass, slim frames and big rooflights for the most open rear room. Across Devon we handle the whole rear extension: survey, drawings, the planning route, building control and the build. Towns we cover here include Plymouth, Exeter and Paignton.
If your garden in Plymouth faces south, expect us to talk about overhangs and solar-control glass before frame colours. Devon has Victorian terraces nearer the centre and post-war semis on the edges. Sloping gardens are frequent, which affects floor levels and steps down to the patio.
How much does a glazed rear extension cost in Devon?
For Devon we work from the South West England rate: £2,910–£4,990 per square metre of new floor, including VAT, standard specification. 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 |
These are guide ranges; the written quote after the survey is the figure that counts.
Do you need planning permission in Devon?
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.
Where in Devon do we work?
FAQ
Questions people ask
Will a glass extension be too hot?
Not if it is designed for its orientation, with solar-control glass, shading and ventilation.
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.
Sliding or bifold doors?
Sliders give bigger panes and slimmer sightlines; bifolds open the whole width. Our guide compares them.
Do you cover all of Devon?
We cover 21 towns and districts in Devon, including Plymouth, Exeter and Paignton.
Who builds the extension?
Vetted building teams working under contract to us; your contract is with S&K Property Investments and Improvement Ltd.