Hatfield, Hertfordshire
Rear extension planning drawings in Hatfield
For homes in Hatfield, a rear extension is often the simplest way to gain space without moving. Measured survey, design options, planning drawings and the application, handled for you. We take it from survey to completion certificate.
Hatfield is covered from our Hertfordshire round, including AL9 and AL10. For Hatfield homes we start with a measured survey, then draw options before anything is submitted.
Book a free site visit
Tell us about the house and we'll call to arrange a free, no-obligation visit.
What do rear extension planning drawings cost in Hatfield?
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 Hatfield?
The planning route for a rear extension in Hatfield 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 Hatfield like to extend?
Post-war semis and newer estates are typical of Hatfield, 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 Hatfield comes together
Survey visit
We visit free of charge, measure up, check access, drainage and neighbours' extensions, and note what you want the room to do.
Options and costs
We draw layout options and price each one, so the budget shapes the design rather than surprising you later.
Planning and regulations
We take the design through the right planning route, then produce the construction drawings and engineer's calculations for building control.
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 Hatfield
Neighbouring places we cover include Welwyn Garden City (2.8 miles) and St Albans (4.8 miles).
- Rear extension planning drawings in Welwyn Garden City
- Rear extension planning drawings in St Albans
- Rear extension planning drawings in Potters Bar
- Rear extension planning drawings in Codicote
- Rear extension planning drawings in Hertford
Other work in Hatfield:
FAQ
Rear extension planning drawings questions in Hatfield
Will I need a structural engineer?
Yes for the beam over the new opening and usually the foundations; we arrange them and their calculations go to building control.
Can I live at home while the extension is built?
Usually yes. Most of the work is outside until the back wall is opened near the end, and that stage is screened off.
Are the drawings mine?
You can use them to get other quotes, subject to the terms.
Do I need planning permission for a rear extension in Hatfield?
Often not for a single-storey rear extension of up to 3 metres (4 metres on a detached house) under permitted development, or up to 6 or 8 metres with prior approval, unless the house is in a conservation area or its rights have been removed.
Can I get a price without a visit?
Our online guide-price tool gives a range in a couple of minutes. A written price needs a survey.
Do I need a party wall agreement?
In England, usually yes if the extension is on or near a shared boundary or the foundations are close to a neighbour's building. We serve the notices.