Rear extension planning drawings in Keynsham

What do rear extension planning drawings cost in Keynsham?

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. We put a fixed price in writing once the design is agreed, and explain any provisional sums such as foundations.

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

Here is how the rules in England apply to a rear extension in Keynsham.

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. At the first visit we measure what is there now and tell you which route fits: permitted development, prior approval or a planning application.

What are homes in Keynsham like to extend?

Stone-built and rendered houses are common around Keynsham, so matching the walling is a design decision in its own right: natural stone, reconstituted stone or a render finish across old and new.

How a rear extension in Keynsham 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. Options and costs

   We draw layout options and price each one, so the budget shapes the design rather than surprising you later.

3. Paperwork handled

   Planning, prior approval or permitted development, Building Regulations approval, structural design and party wall notices are all handled by us.

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 Keynsham

Neighbouring places we cover include Kingswood (2.7 miles) and Mangotsfield (5.1 miles).

• Rear extension planning drawings in Kingswood
• Rear extension planning drawings in Mangotsfield
• Rear extension planning drawings in Bristol
• Rear extension planning drawings in Bishopsworth
• Rear extension planning drawings in Bath

Other work in Keynsham:

• Single-storey rear extension
• Two-storey rear extension
• Kitchen-diner rear extension
• Side return extension
• Wraparound extension
• Glazed rear extension

All rear extensions in Keynsham