Rear extension planning drawings in St Austell

What do rear extension planning drawings cost in St Austell?

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 St Austell?

The planning route for a rear extension in St Austell 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 St Austell like to extend?

Stone-built and rendered houses are common around St Austell, 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 St Austell 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 St Austell

Close by, we work in Bodmin, about 9.2 miles away, and Truro, about 13.5 miles away.

• Rear extension planning drawings in Bodmin
• Rear extension planning drawings in Truro
• Rear extension planning drawings in Newquay
• Rear extension planning drawings in Falmouth
• Rear extension planning drawings in Redruth

Other work in St Austell:

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

All rear extensions in St Austell