Northampton, Northamptonshire
Glazed rear extension in Northampton
Full-height glass, slim frames and big rooflights for the most open rear room. If you live in Northampton 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.
Northampton is covered from our Northamptonshire round, including NN1, NN2, NN3 and NN4. If your garden in Northampton 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 Northampton?
For Northampton we work from the East Midlands rate: £2,720–£4,660 per square metre of new floor, including VAT, standard specification. East Midlands prices sit a little below our West Midlands baseline.
| Size | Guide price inc VAT |
|---|---|
| 3 m wide × 4 m deep (12 m²) | £32,500–£56,000 |
| 4 m wide × 6 m deep (24 m²) | £65,000–£111,500 |
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 Northampton?
The planning route for a glazed rear extension in Northampton is set by England's householder rules and your council.
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. Before any drawing we look up the property's history with the council, because earlier extensions and removed rights change the answer.
What are homes in Northampton like to extend?
Red-brick terraces and semis are typical of Northampton. Coal-mining legacy areas in parts of the East Midlands can need a Coal Authority check before foundations are designed.
How a glazed rear extension in Northampton 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.
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.
Build and sign-off
We build to the approved drawings with regular updates, then hand over the building control completion certificate and any guarantees from suppliers.
Glazed rear extensions near Northampton
Close by, we work in Wellingborough, about 8.8 miles away, and Daventry, about 11.7 miles away.
- Glazed rear extension in Wellingborough
- Glazed rear extension in Daventry
- Glazed rear extension in Rushden
- Glazed rear extension in Kettering
- Glazed rear extension in Newport Pagnell
Other work in Northampton:
FAQ
Glazed rear extension questions in Northampton
What postcode areas do you cover around Northampton?
Including NN1, NN2, NN3, NN4 and NN7, and the surrounding Northamptonshire area.
Is the site visit in Northampton free?
Yes. We visit, measure up and talk through the options with no cost and no obligation.
Is a glass box a conservatory?
No. It is built to Building Regulations as part of the house, with insulated floor and roof, so it is usable all year.
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.
Can you match the brick or stone on my Northampton 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.