Cornwall
Roof lanterns and rooflights for rear extensions in Cornwall
Lanterns, flat rooflights and walk-on glass that bring light deep into the plan. We design and build rear extensions across Cornwall, from Redruth and Falmouth to St Austell, covering single-storey kitchen extensions, two-storey additions, side returns and wraparounds.
Rear extensions in Cornwall gain most from a rooflight placed against the old back wall, where the room would otherwise be darkest. Cornwall 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.
What does it cost in Cornwall?
As a guide, £2,200–£4,500 including VAT. These are guide ranges; the written quote after the survey is the figure that counts.
What approvals does it need in Cornwall?
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 Cornwall do we work?
FAQ
Questions people ask
Lantern or flat rooflight?
A lantern gives height and a feature; a flat rooflight is cleaner and lower-profile.
Do rooflights count towards the 25% glazing limit?
Yes, in England's simple route; more is possible with a calculation.
Can a rooflight open?
Yes, manually or electrically, with rain sensors.
Do you cover all of Cornwall?
We cover 10 towns and districts in Cornwall, including Redruth, Falmouth and St Austell.
Who builds the extension?
Vetted building teams working under contract to us; your contract is with S&K Property Investments and Improvement Ltd.