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Northamptonshire

Rear extensions in Kettering

We design and build rear extensions for homes in Kettering, Northamptonshire, from single-storey kitchen-diners across the back of the house to two-storey extensions that add a bedroom above.

Kettering is in Northamptonshire, with postcode districts including NN15 and NN16. The nearest places we also cover are Desborough (5.0 miles) and Wellingborough (6.7 miles).

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Tell us about the house and we'll call to arrange a free, no-obligation visit.

Rear extensions we build in Kettering

Also available across Northamptonshire:

Rear extension prices in Kettering

East Midlands prices sit a little below our West Midlands baseline.

ExampleGuide inc VAT
Single-storey, 3 m × 4 m (12 m²)£22,000–£36,000
Single-storey, 4 m × 6 m (24 m²)£44,000–£72,000
Two-storey, 3 m × 5 m footprint (30 m²)£52,500–£78,500
Side return, about 14 m²£31,000–£51,500
Wraparound, about 25 m²£53,500–£87,500

What are homes in Kettering like to extend?

Red-brick terraces and semis are typical of Kettering. Coal-mining legacy areas in parts of the East Midlands can need a Coal Authority check before foundations are designed.

Planning rules for Kettering

English permitted development (Class A) allows a single-storey rear extension of 3 metres on a terraced or semi-detached house and 4 metres on a detached one, measured from the original house, with a maximum height of 4 metres and eaves of no more than 3 metres within 2 metres of a boundary.

If 3 or 4 metres is not enough, England's prior approval route allows 6 metres on a terraced or semi-detached house and 8 metres on a detached house for a single-storey rear extension. Neighbours are consulted, the council decides within 42 days, and the fee is £249, rising to £310 from 8 December 2026.

Planning and Building Regulations are separate in England: even a permitted development extension is inspected for foundations, drainage, structure, insulation, fire safety and ventilation, through the council or a registered building control approver, ending with a completion certificate.

Nearby towns

FAQ

Questions people ask

How much is a rear extension in Kettering?

A 3 m × 4 m single-storey rear extension is about £22,000–£36,000 including VAT at our East Midlands guide rates; the written price follows a survey.

Do I need planning permission in Kettering?

Often not for a single-storey rear extension of up to 3 metres (4 metres on a detached house) under permitted development, or up to 6 or 8 metres with prior approval, unless the house is in a conservation area or its rights have been removed.

Is the site visit in Kettering free?

Yes, with no obligation.

Do I need a party wall agreement?

In England, usually yes if the extension is on or near a shared boundary or the foundations are close to a neighbour's building. We serve the notices.

Next step

See what your rear extension would cost

Get a guide price online in a couple of minutes, or book a free site visit and we'll measure up and talk you through the planning route.

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