Rear extension planning drawings in St Helens

What do rear extension planning drawings cost in St Helens?

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 Helens?

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

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 St Helens like to extend?

Stone and brick terraces are common around St Helens. Where houses back onto a ginnel or alley, deliveries can come in from the rear, which makes the build tidier.

How a rear extension in St Helens 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. Drawings and budget

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

3. Paperwork handled

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

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 Helens

From St Helens, the nearest places we also cover are Haydock (2.4 miles) and Rainhill (2.7 miles).

• Rear extension planning drawings in Haydock
• Rear extension planning drawings in Rainhill
• Rear extension planning drawings in Whiston
• Rear extension planning drawings in Prescot
• Rear extension planning drawings in Ashton in Makerfield

Other work in St Helens:

• 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 Helens