Harpenden, Hertfordshire
Bungalow rear extension in Harpenden
We plan and build rear extensions for bungalows for homeowners in Harpenden. Single-storey rear extensions that keep everything on one level. Start with a free site visit, then a written price once the design is agreed.
Harpenden and its postcode districts AL5 are part of our Hertfordshire coverage. For Harpenden bungalows we design the roof first, because the low eaves decide the height of the new room.
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 bungalow rear extension cost in Harpenden?
For Harpenden we work from the East of England rate: £1,960–£3,180 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 m deep (12 m²) | £23,500–£38,000 |
| 4 m wide × 6 m deep (24 m²) | £47,000–£76,500 |
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 bungalow rear extension in Harpenden?
Whether your bungalow rear extension in Harpenden needs a planning application depends on its size, your house and any local restrictions.
English permitted development (Class A) allows a single-storey rear extension of 3 metres on a terraced or semi-detached house and 4 metres on a detached one, measured from the original house, with a maximum height of 4 metres and eaves of no more than 3 metres within 2 metres of a boundary.
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. 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 bungalow rear extension in Harpenden 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.
Paperwork handled
Planning, prior approval or permitted development, Building Regulations approval, structural design and party wall notices are all handled by us.
Build and sign-off
We build to the approved drawings with regular updates, then hand over the building control completion certificate and any guarantees from suppliers.
Bungalow rear extensions near Harpenden
Neighbouring places we cover include St Albans (4.7 miles) and Luton (5.0 miles).
- Bungalow rear extension in St Albans
- Bungalow rear extension in Luton
- Bungalow rear extension in Codicote
- Bungalow rear extension in Hemel Hempstead
- Bungalow rear extension in Welwyn Garden City
Other work in Harpenden:
FAQ
Bungalow rear extension questions in Harpenden
Is the site visit in Harpenden free?
Yes. We visit, measure up and talk through the options with no cost and no obligation.
Do I need planning permission for a rear extension in Harpenden?
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.
Will the roof look odd?
Not if the pitch and tiles match. Where the eaves are low, a flat-roofed section with a lantern is an alternative.
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.
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.