Harpenden, Hertfordshire
Terraced house rear extension in Harpenden
Rear and side return extensions for terraces, with access through the house and two neighbours. We design, get the approvals for and build rear extensions for terraced houses in Harpenden and the surrounding area, with one contract from the first survey to building control sign-off.
Harpenden is covered from our Hertfordshire round, including AL5. On a Harpenden terrace both neighbours usually need party wall notices or agreement, so we talk to them early.
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 Harpenden?
A terraced house rear extension in Harpenden is priced at £2,170–£3,500 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 × 4.5 m deep (13.5 m²) | £29,500–£47,000 |
| 3 m wide × 6 m deep (18 m²) | £39,000–£63,000 |
These are guide ranges; the written quote after the survey is the figure that counts.
Do you need planning permission for a terraced house rear extension in Harpenden?
The planning route for a terraced house rear extension in Harpenden is set by England's householder rules and your council.
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.
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 Harpenden like to extend?
Harpenden mixes Victorian terraces with 1930s semis, so both side returns and full-width kitchen extensions suit houses here.
How a terraced house rear extension in Harpenden comes together
Free site visit
We measure the house and garden, look at the back wall, drainage and boundaries, and talk through what you want from the space.
Drawings and budget
Floor plans and elevations for the options, each with a guide price.
Paperwork handled
Planning, prior approval or permitted development, Building Regulations approval, structural design and party wall notices are all handled by us.
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 Harpenden
Close by, we work in St Albans, about 4.7 miles away, and Luton, about 5.0 miles away.
- Terraced house rear extension in St Albans
- Terraced house rear extension in Luton
- Terraced house rear extension in Codicote
- Terraced house rear extension in Hemel Hempstead
- Terraced house rear extension in Welwyn Garden City
Other work in Harpenden:
FAQ
Terraced house rear extension questions in Harpenden
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.
Is the site visit in Harpenden free?
Yes. We visit, measure up and talk through the options with no cost and no obligation.
Will my terrace be in a conservation area?
Many Victorian terraces are. Your council's map shows it; we check at the survey.
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.
How long does a rear extension take to build in Harpenden?
Most single-storey rear extensions take 10 to 16 weeks on site and two-storey extensions 16 to 26 weeks, after design and approvals.
Do you handle building control in Harpenden?
Yes. We apply to the council or a registered building control approver and hand over the completion certificate.