Cambridgeshire
Glazed and glass-box rear extensions in Cambridgeshire
Full-height glass, slim frames and big rooflights for the most open rear room. Across Cambridgeshire we handle the whole rear extension: survey, drawings, the planning route, building control and the build. Towns we cover here include Peterborough, Cambridge and Wisbech.

If your garden in Peterborough faces south, expect us to talk about overhangs and solar-control glass before frame colours. Cambridgeshire mixes Victorian terraces with 1930s semis, so both side returns and full-width kitchen extensions suit houses here.
How much does a glazed rear extension cost in Cambridgeshire?
For Cambridgeshire we work from the East of England rate: £2,970–£5,090 per square metre of new floor, including VAT, 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 |
Ground conditions, glazing, the roof and how far the house is opened up move the final figure within the range.
Do you need planning permission in Cambridgeshire?
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 Cambridgeshire 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 Cambridgeshire?
We cover 11 towns and districts in Cambridgeshire, including Peterborough, Cambridge and Wisbech.
Who builds the extension?
Vetted building teams working under contract to us; your contract is with S&K Property Investments and Improvement Ltd.