Extending your home in Corby
We design and build house extensions for homes in Corby and the surrounding Northamptonshire area, with guide prices adjusted for the region.
- Postcode districtsNN17, NN18
- Price regionEast Midlands (×0.95)
- Planning rulesEngland
- Site visitFree, no obligation
Planning and building control in Corby
In England a single-storey rear extension can usually go up to 3 m beyond the original rear wall of a semi-detached or terraced house, or 4 m on a detached house, without a planning application, provided it is no more than 4 m high, keeps eaves to 3 m within 2 m of a boundary and, with other buildings, covers no more than half the land around the original house. The larger home extension prior approval scheme raises those depths to 6 m and 8 m, with neighbours notified and a 42-day decision.
In England a single-storey side return infill is often permitted development if it stays within the height limits and is no wider than half the width of the original house. Conservation areas, listed buildings and flats always need an application, and the boundary wall usually brings in the Party Wall Act.
In a conservation area, national park, National Landscape, the Broads or a World Heritage Site the permitted development limits are tighter (no side or two-storey extensions without an application). Listed homes need listed building consent, and if permitted development rights have been removed, any extension needs an application.
Building regulations approval is separate from planning. In England you can use the council's building control team or a registered building control approver; a full plans application gets the drawings checked before work starts, and the inspector signs the work off with a completion certificate.
Applications are decided by the local planning authority (your district, borough or unitary council).
Covering Corby and nearby
We cover Corby and the postcode districts NN17, NN18. Nearby, we also take on projects in Kettering (7 miles), Market Harborough (10 miles), Wellingborough (13 miles), Rushden (15 miles), Northampton (19 miles). Oakham, in Rutland, is roughly 11 miles from Corby and also on our list.
Choosing the right extension in Corby
The East Midlands has plenty of inter-war and post-war semis and detached houses with room to extend, alongside Victorian terraces in the towns.
Depending on the plot, conservatory replacement extensions and double-storey extensions are often the strongest options, with single-storey rear extensions worth considering where there is room.
Guide prices for Corby
Use these Corby guide prices to sense-check a budget; the guide-price tool narrows them to your own size, and the site visit turns them into a written figure.
| Extension type | Example size | Standard spec (inc VAT) |
|---|---|---|
| Side return extensions | 11 m² | £25,000 – £31,500 |
| Single-storey rear extensions | 20 m² | £38,500 – £49,500 |
| Kitchen extensions | 20 m² | £39,500 – £50,500 |
| Conservatory replacement extensions | 14 m² | £28,500 – £37,000 |
| Double-storey extensions | 32 m² | £54,500 – £71,500 |
| Orangery extensions | 16 m² | £42,500 – £53,500 |
Choose an extension type
- Side return extensions · from £17,000
- Single-storey rear extensions · from £19,500
- Bungalow extensions · from £24,500
- Conservatory replacement extensions · from £19,000
- Side extensions · from £20,500
- Glass box extensions · from £28,500
- Extensions over a garage · from £22,500
- Annexe extensions · from £52,000
- Wraparound extensions · from £34,000
- Home office extensions · from £15,000
- Timber frame extensions · from £19,500
- Pitched roof extensions · from £21,000
- Double-storey extensions · from £36,000
- Extension plans and drawings · from £1,100
- Porch extensions · from £3,800
- Planning permission for extensions · from £300
- Flat roof extensions · from £19,500
- Utility and boot room extensions · from £13,000
- Orangery extensions · from £28,500
- Bedroom extensions · from £24,500
- Kitchen extensions · from £25,500
- Building regulations for extensions · from £850
Free site visit
It starts with a visit to your house to measure, check access and talk through ideas and budget.
Design and approvals
Drawings are prepared and agreed with you, then submitted for the right planning route and building regulations approval.
Fixed written price
We confirm the build price in writing, based on the approved drawings and the finishes you have chosen.
Build and sign-off
The build is managed from start to finish, inspected at each stage and signed off on completion.
Questions about extensions in Corby
How much does an extension cost in Corby?
Using our East Midlands factor (×0.95), a standard-spec single-storey extension of 20 m² is a guide £38,500 to £49,500 including VAT, and a 32 m² two-storey extension £54,500 to £71,500. Your written price follows the survey.
Can I get a price before anyone visits?
Yes. This page shows guide prices adjusted for Corby, and the guide-price tool gives a range for your own size and finish in about a minute.
Do you cover all of Corby?
Yes, including the surrounding parts of Northamptonshire. Site visits are free and there is no obligation.
How long does an extension take in Corby?
Usually 2 to 4 months of design and approvals, then 10 to 16 weeks on site for a single-storey extension or 16 to 24 weeks for two storeys.
Do you handle building regulations?
Yes. We prepare the drawings and calculations, submit them and book inspections, ending with a completion certificate.
Book a free site visit in Corby
We will measure up, check the planning position and give you honest guide figures.
- Free, no-obligation site visit
- Planning route checked before you spend on drawings
- Written price once the design is agreed
- Building control sign-off at the end
Prefer to talk? Call 0800 088 6341 or .
Book a free site visit
Tell us a little about the project and we will arrange a time.