Welwyn Garden City, Hertfordshire
Two-storey rear extension in Welwyn Garden City
Thinking about a two-storey rear extension in Welwyn Garden City? A larger kitchen downstairs and an extra bedroom or bathroom upstairs, under one roof. Our team handles the drawings, the planning route and the build, and your contract is with one company throughout.
Welwyn Garden City sits in Hertfordshire, with postcode districts including AL7 and AL8. In Welwyn Garden City, a two-storey rear extension is worth comparing with the cost of moving once stamp duty, agents' and legal fees are counted.
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 Welwyn Garden City?
In Welwyn Garden City, 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 |
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 two-storey rear extension in Welwyn Garden City?
The planning route for a two-storey rear extension in Welwyn Garden City is set by England's householder rules and your council.
A two-storey rear extension can be permitted development in England only if it projects no more than 3 metres, stays at least 7 metres from the rear boundary, matches the existing roof pitch and has obscure-glazed upper side windows. In practice most double-storey rear extensions go through a householder planning application.
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?
Welwyn Garden City mixes Victorian terraces with 1930s semis, so both side returns and full-width kitchen extensions suit houses here.
How a two-storey 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.
Drawings and budget
Floor plans and elevations for the options, each with a guide price.
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.
Two-storey rear extensions near Welwyn Garden City
Neighbouring places we cover include Hatfield (2.8 miles) and Codicote (3.6 miles).
- Two-storey rear extension in Hatfield
- Two-storey rear extension in Codicote
- Two-storey rear extension in Hertford
- Two-storey rear extension in St Albans
- Two-storey rear extension in Harpenden
Other work in Welwyn Garden City:
FAQ
Two-storey rear extension questions in Welwyn Garden City
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.
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.
Can it be built on a terraced house?
Sometimes, but the upper floor is harder to get through planning on a terrace because of the effect on neighbours. A single-storey extension with a loft conversion is often an easier route.
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.
Do I need planning permission for a rear extension in Welwyn Garden City?
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.