Rear extension planning drawings in Dorchester

What do rear extension planning drawings cost in Dorchester?

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 Dorchester?

Planning for a rear extension in Dorchester follows the English householder rules.

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 Dorchester like to extend?

Stone-built and rendered houses are common around Dorchester, 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 Dorchester comes together

1. Look round and measure

   A free visit to see the back of the house, measure it, check the drains and boundaries and hear what you need.

2. Drawings and budget

   Floor plans and elevations for the options, each with a guide price.

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. Written price, then build

   Once the design and approvals are in place, you get a fixed written price and programme, and we build through to sign-off.

Rear extension planning drawings near Dorchester

We also build rear extensions in nearby Weymouth (7.2 miles) and Portland (10.3 miles).

• Rear extension planning drawings in Weymouth
• Rear extension planning drawings in Portland
• Rear extension planning drawings in Bridport
• Rear extension planning drawings in Blandford Forum
• Rear extension planning drawings in Yeovil

Other work in Dorchester:

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

All rear extensions in Dorchester