Abbots Langley, Hertfordshire
Semi-detached rear extension in Abbots Langley
Thinking about a semi-detached rear extension in Abbots Langley? Single or two-storey extensions for semi-detached houses, with side access and one party wall. Our team handles the drawings, the planning route and the build, and your contract is with one company throughout.
Abbots Langley and its postcode districts WD5 are part of our Hertfordshire coverage. Semi-detached houses are common across Hertfordshire, and their side access makes rear extensions quicker to build.
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 semi-detached rear extension cost in Abbots Langley?
A semi-detached rear extension in Abbots Langley is priced at £2,010–£3,290 per square metre including VAT as a guide, before kitchen fit-out and fees. 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 m deep (12 m²) | £24,000–£39,500 |
| 4 m wide × 5 m deep (20 m²) | £40,500–£65,500 |
| 4 m wide × 6 m deep (24 m²) | £48,500–£79,000 |
These are guide ranges; the written quote after the survey is the figure that counts.
Do you need planning permission for a semi-detached rear extension in Abbots Langley?
Planning for a semi-detached rear extension in Abbots Langley follows the English householder rules.
In England a single-storey rear extension can often be built under permitted development: up to 3 metres beyond the original rear wall of an attached house, or 4 metres on a detached house, no higher than 4 metres, with eaves no higher than 3 metres if any part is within 2 metres of a boundary.
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.
If 3 or 4 metres is not enough, England's prior approval route allows 6 metres on a terraced or semi-detached house and 8 metres on a detached house for a single-storey rear extension. Neighbours are consulted, the council decides within 42 days, and the fee is £249, rising to £310 from 8 December 2026.
Conservation areas, National Parks, National Landscapes and the Broads restrict permitted development, and listed buildings always need listed building consent. Before any drawing we look up the property's history with the council, because earlier extensions and removed rights change the answer.
What are homes in Abbots Langley like to extend?
Abbots Langley mixes Victorian terraces with 1930s semis, so both side returns and full-width kitchen extensions suit houses here.
How a semi-detached rear extension in Abbots Langley 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.
Design and guide price
Two or three layout options with a guide price for each, so you choose the design knowing what it costs.
Planning and regulations
We take the design through the right planning route, then produce the construction drawings and engineer's calculations for building control.
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.
Semi-detached rear extensions near Abbots Langley
Close by, we work in North Watford, about 2.0 miles away, and West Watford, about 3.3 miles away.
- Semi-detached rear extension in North Watford
- Semi-detached rear extension in West Watford
- Semi-detached rear extension in Hemel Hempstead
- Semi-detached rear extension in Watford
- Semi-detached rear extension in St Albans
Other work in Abbots Langley:
FAQ
Semi-detached rear extension questions in Abbots Langley
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.
What postcode areas do you cover around Abbots Langley?
Including WD5, and the surrounding Hertfordshire area.
Do I need a party wall agreement?
Usually with the attached neighbour, in England and Wales.
How much does a semi-detached rear extension cost in Abbots Langley?
As a guide, £2,010–£3,290 per square metre including VAT for a standard specification. For example, 3 m wide × 4 m deep (12 m²): about £24,000–£39,500 at that rate. Your written price follows the survey.
Do I need planning permission for a rear extension in Abbots Langley?
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.
Do you handle building control in Abbots Langley?
Yes. We apply to the council or a registered building control approver and hand over the completion certificate.