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Gainsborough, Lincolnshire

Rear extension planning drawings in Gainsborough

Rear extension planning drawings in Gainsborough: measured survey, design options, planning drawings and the application, handled for you. We measure the house, show you what the rules allow, price it in writing and build it.

Gainsborough and its postcode districts DN21 are part of our Lincolnshire coverage. Planning applications in Gainsborough go to the local planning authority covering Gainsborough, and we check its local design guidance for rear extensions before drawing.

Book a free site visit

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

What do rear extension planning drawings cost in Gainsborough?

As a guide, £1,000–£2,500 including VAT for a single-storey rear extension, or £2,000–£3,500 for a two-storey scheme. A householder planning application in England costs £548 (£575 for applications made from 8 December 2026), and a lawful development certificate for proposed work costs half the householder fee. These are guide ranges; the written quote after the survey is the figure that counts.

Do you need planning permission for a rear extension in Gainsborough?

The planning route for a rear extension in Gainsborough is set by England's householder rules and your council.

A two-storey rear extension can be permitted development in England only if it projects no more than 3 metres, stays at least 7 metres from the rear boundary, matches the existing roof pitch and has obscure-glazed upper side windows. In practice most double-storey rear extensions go through a householder planning application.

Councils aim to decide householder applications within 8 weeks of validation, and prior approval within 42 days.

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 Gainsborough like to extend?

Gainsborough has plenty of inter-war semis and bungalows, and single-storey rear extensions suit both.

How a rear extension in Gainsborough comes together

  1. Free site visit

    We measure the house and garden, look at the back wall, drainage and boundaries, and talk through what you want from the space.

  2. Design and guide price

    Two or three layout options with a guide price for each, so you choose the design knowing what it costs.

  3. Approvals

    Permitted development check, prior approval or planning application, then Building Regulations drawings and structural calculations, plus party wall notices where they apply.

  4. 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.

Rear extension planning drawings near Gainsborough

From Gainsborough, the nearest places we also cover are Retford (8.4 miles) and Scunthorpe (14.3 miles).

Other work in Gainsborough:

All rear extensions in Gainsborough

FAQ

Rear extension planning drawings questions in Gainsborough

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.

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.

Are the drawings mine?

You can use them to get other quotes, subject to the terms.

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.

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.

What postcode areas do you cover around Gainsborough?

Including DN21, and the surrounding Lincolnshire area.

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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