Hertford, Hertfordshire
Two-storey rear extension in Hertford
A larger kitchen downstairs and an extra bedroom or bathroom upstairs, under one roof. If you live in Hertford and want to know what a two-storey rear extension would cost and whether it needs planning, start with the online guide price or a free site visit.
We cover Hertford (SG13 and SG14) as part of our Hertfordshire work. In Hertfordshire we check the neighbours' rear windows first, because the upper floor is where most two-storey schemes win or lose planning.
Book a free site visit
Tell us about the house and we'll call to arrange a free, no-obligation visit.
How much does a two-storey rear extension cost in Hertford?
In Hertford, our guide for a two-storey rear extension is £1,910–£2,860 per square metre including VAT for a standard specification. East of England prices run slightly above our West Midlands baseline; clay soils near trees are the main foundation variable.
| Size | Guide price inc VAT |
|---|---|
| 3 m × 5 m footprint, two floors (30 m²) | £57,000–£86,000 |
| 4 m × 6 m footprint, two floors (48 m²) | £91,500–£137,500 |
Your written price follows a measured survey and an agreed design, so it reflects your house, not an average.
Do you need planning permission for a two-storey rear extension in Hertford?
Here is how the rules in England apply to a two-storey rear extension in Hertford.
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.
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 Hertford like to extend?
Post-war semis and newer estates are typical of Hertford, 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 two-storey rear extension in Hertford 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.
Approvals
Permitted development check, prior approval or planning application, then Building Regulations drawings and structural calculations, plus party wall notices where they apply.
Fixed price and build
A written price for the agreed design, a start date and a named contact through the build, ending with the building control completion certificate.
Two-storey rear extensions near Hertford
From Hertford, the nearest places we also cover are Ware (2.4 miles) and Hoddesdon (3.7 miles).
- Two-storey rear extension in Ware
- Two-storey rear extension in Hoddesdon
- Two-storey rear extension in Broxbourne
- Two-storey rear extension in Welwyn Garden City
- Two-storey rear extension in Hatfield
Other work in Hertford:
FAQ
Two-storey rear extension questions in Hertford
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.
Is the site visit in Hertford free?
Yes. We visit, measure up and talk through the options with no cost and no obligation.
Will we need to move out?
Rarely. The first-floor opening is made late in the job and sealed with temporary screens.
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.
Do I need planning permission for a rear extension in Hertford?
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.
What postcode areas do you cover around Hertford?
Including SG13 and SG14, and the surrounding Hertfordshire area.