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Chalfont St Peter, Buckinghamshire

Rear extension planning drawings in Chalfont St Peter

Measured survey, design options, planning drawings and the application, handled for you. If you live in Chalfont St Peter and want to know what a rear extension would cost and whether it needs planning, start with the online guide price or a free site visit.

Chalfont St Peter is covered from our Buckinghamshire round, including SL9. Planning applications in Chalfont St Peter go to the local planning authority covering Chalfont St Peter, 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 Chalfont St Peter?

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 Chalfont St Peter?

Planning for a rear extension in Chalfont St Peter follows the English householder rules.

England's rules allow a rear extension of more than one storey without an application only when it is no deeper than 3 metres and at least 7 metres from the boundary opposite the rear wall, and never on designated land. Most two-storey schemes need householder planning permission.

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. 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 Chalfont St Peter like to extend?

Around Chalfont St Peter the housing ranges from inter-war semis to 1960s and 1970s estates with good-sized gardens. Many of the newer estates had permitted development rights removed by condition, so we check the planning history before anything is drawn.

How a rear extension in Chalfont St Peter comes together

  1. Survey visit

    We visit free of charge, measure up, check access, drainage and neighbours' extensions, and note what you want the room to do.

  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. Planning and regulations

    We take the design through the right planning route, then produce the construction drawings and engineer's calculations for building control.

  4. 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.

Rear extension planning drawings near Chalfont St Peter

Neighbouring places we cover include Gerrards Cross (1.6 miles) and Chorleywood (3.6 miles).

Other work in Chalfont St Peter:

All rear extensions in Chalfont St Peter

FAQ

Rear extension planning drawings questions in Chalfont St Peter

How long does a rear extension take to build in Chalfont St Peter?

Most single-storey rear extensions take 10 to 16 weeks on site and two-storey extensions 16 to 26 weeks, after design and approvals.

Do you handle building control in Chalfont St Peter?

Yes. We apply to the council or a registered building control approver and hand over the completion certificate.

Are the drawings mine?

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

Is the site visit in Chalfont St Peter free?

Yes. We visit, measure up and talk through the options with no cost and no obligation.

What do rear extension planning drawings cost in Chalfont St Peter?

As a guide, £1,000–£2,500 including VAT for a single-storey rear extension and £2,000–£3,500 for a two-storey scheme, covering the measured survey, design options and the application. The council fee is extra.

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.

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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