Rear extension planning drawings in Watford

What do rear extension planning drawings cost in Watford?

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. Ground conditions, glazing, the roof and how far the house is opened up move the final figure within the range.

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

The planning route for a rear extension in Watford is set by England's householder rules and your council.

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. 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 Watford like to extend?

Post-war semis and newer estates are typical of Watford, and many have room for a full-width extension. Shrinkable clay is common in the East of England, so foundations near trees and hedges are designed to NHBC-style depth guidance.

How a rear extension in Watford 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. 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 Watford

We also build rear extensions in nearby West Watford (0.9 miles) and Bushey (1.7 miles).

• Rear extension planning drawings in West Watford
• Rear extension planning drawings in Bushey
• Rear extension planning drawings in North Watford
• Rear extension planning drawings in Croxley Green
• Rear extension planning drawings in Northwood

Other work in Watford:

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

All rear extensions in Watford