Welwyn Garden City, Hertfordshire
Terraced house rear extension in Welwyn Garden City
For homes in Welwyn Garden City, a terraced house rear extension is often the simplest way to gain space without moving. Rear and side return extensions for terraces, with access through the house and two neighbours. We take it from survey to completion certificate.
We cover Welwyn Garden City (AL7 and AL8) as part of our Hertfordshire work. In Welwyn Garden City we plan the delivery route through the house and the skip licence before anything else.
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 terraced house rear extension cost in Welwyn Garden City?
For Welwyn Garden City we work from the East of England rate: £2,170–£3,500 per square metre of new floor, including VAT, 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 wide × 4.5 m deep (13.5 m²) | £29,500–£47,000 |
| 3 m wide × 6 m deep (18 m²) | £39,000–£63,000 |
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 terraced house rear extension in Welwyn Garden City?
The planning route for a terraced house rear extension in Welwyn Garden City is set by England's householder rules and your council.
Under England's householder permitted development rules you can usually add 3 metres at the back of an attached house, or 4 metres on a detached house, without a planning application, as long as the extension stays under 4 metres high and its eaves stay under 3 metres where it is within 2 metres of a boundary.
The Party Wall etc. Act 1996 applies in England: you serve notice two months before work to a shared wall, and one month before digging foundations within 3 metres (or 6 metres for deeper foundations) of a neighbour's building. Neighbours can agree in writing; if they dissent, surveyors agree an award.
Conservation areas, National Parks, National Landscapes and the Broads restrict permitted development, and listed buildings always need listed building consent. At the first visit we measure what is there now and tell you which route fits: permitted development, prior approval or a planning application.
What are homes in Welwyn Garden City like to extend?
Post-war semis and newer estates are typical of Welwyn Garden City, 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 terraced house rear extension in Welwyn Garden City comes together
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.
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.
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.
Terraced house rear extensions near Welwyn Garden City
Close by, we work in Hatfield, about 2.8 miles away, and Codicote, about 3.6 miles away.
- Terraced house rear extension in Hatfield
- Terraced house rear extension in Codicote
- Terraced house rear extension in Hertford
- Terraced house rear extension in St Albans
- Terraced house rear extension in Harpenden
Other work in Welwyn Garden City:
FAQ
Terraced house rear extension questions in Welwyn Garden City
Can you match the brick or stone on my Welwyn Garden City house?
We source the closest match and show you samples before ordering; reclaimed materials are often the best match on older houses.
How long does a rear extension take to build in Welwyn Garden City?
Most single-storey rear extensions take 10 to 16 weeks on site and two-storey extensions 16 to 26 weeks, after design and approvals.
How deep can I go on a terrace?
3 metres under permitted development in England, or up to 6 metres with prior approval outside designated land.
Is the site visit in Welwyn Garden City free?
Yes. We visit, measure up and talk through the options with no cost and no obligation.
What postcode areas do you cover around Welwyn Garden City?
Including AL7 and AL8, and the surrounding Hertfordshire area.
Who will build my extension?
Vetted building teams working under contract to us. Your contract is with S&K Property Investments and Improvement Ltd for the design and the build.