Portishead, Somerset
Glazed rear extension in Portishead
Thinking about a glazed rear extension in Portishead? 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.
Portishead and its postcode districts BS20 are part of our Somerset coverage. If your garden in Portishead 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 Portishead?
A glazed rear extension in Portishead 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 |
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 for a glazed rear extension in Portishead?
Planning for a glazed rear extension in Portishead 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. We check your house's planning history and any conservation area before drawing, so the route is clear before you spend on plans.
What are homes in Portishead like to extend?
Portishead 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 a glazed rear extension in Portishead comes together
Look round and measure
A free visit to see the back of the house, measure it, check the drains and boundaries and hear what you need.
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.
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 Portishead
We also build glazed and glass-box rear extensions in nearby Nailsea (3.5 miles) and Clevedon (4.7 miles).
- Glazed rear extension in Nailsea
- Glazed rear extension in Clevedon
- Glazed rear extension in Yatton
- Glazed rear extension in Caldicot
- Glazed rear extension in Bristol
Other work in Portishead:
FAQ
Glazed rear extension questions in Portishead
Can you match the brick or stone on my Portishead house?
We source the closest match and show you samples before ordering; reclaimed materials are often the best match on older houses.
Can I get a price without a visit?
Our online guide-price tool gives a range in a couple of minutes. A written price needs a survey.
Can I have a level threshold?
Yes, with a drainage channel outside the doors and the slab set to the patio level.
How much does a glazed rear extension cost in Portishead?
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.
Do you handle building control in Portishead?
Yes. We apply to the council or a registered building control approver and hand over the completion certificate.
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.