Extensions in Berkhamsted: design, planning and build
Looking to extend your home in Berkhamsted? Start here: extension types, guide prices for Berkhamsted, the planning rules that apply and how a project runs.
- Postcode districtsHP4
- Price regionEast of England (×1.06)
- Planning rulesEngland
- Site visitFree, no obligation
Do extensions in Berkhamsted need planning permission?
In England a single-storey rear extension can usually go up to 3 m beyond the original rear wall of a semi-detached or terraced house, or 4 m on a detached house, without a planning application, provided it is no more than 4 m high, keeps eaves to 3 m within 2 m of a boundary and, with other buildings, covers no more than half the land around the original house. The larger home extension prior approval scheme raises those depths to 6 m and 8 m, with neighbours notified and a 42-day decision.
In England a single-storey side extension can be permitted development if it is no more than 4 m high and no wider than half the width of the original house. Two-storey side extensions, and any side extension on designated land such as a conservation area, need a householder planning application.
In a conservation area, national park, National Landscape, the Broads or a World Heritage Site the permitted development limits are tighter (no side or two-storey extensions without an application). Listed homes need listed building consent, and if permitted development rights have been removed, any extension needs an application.
Building regulations approval is separate from planning. In England you can use the council's building control team or a registered building control approver; a full plans application gets the drawings checked before work starts, and the inspector signs the work off with a completion certificate.
Applications are decided by the local planning authority (your district, borough or unitary council).
Which extension suits a Berkhamsted home?
Across the East of England many houses sit on generous plots, and single-storey and wraparound extensions are a natural fit.
For many houses here, bungalow extensions, double-storey extensions or wraparound extensions gives the most useful space for the budget.
Guide prices for Berkhamsted
We publish guide prices so you can budget before anyone visits. For Berkhamsted they are adjusted by ×1.06, the factor we use across East of England.
| Extension type | Example size | Standard spec (inc VAT) |
|---|---|---|
| Double-storey extensions | 32 m² | £61,000 – £80,000 |
| Conservatory replacement extensions | 14 m² | £31,500 – £41,000 |
| Side return extensions | 11 m² | £27,500 – £35,000 |
| Wraparound extensions | 25 m² | £60,500 – £77,000 |
| Extensions over a garage | 12 m² | £26,500 – £34,500 |
Covering Berkhamsted and nearby
Site visits are available across Berkhamsted (HP4). Nearby, we also take on projects in Hemel Hempstead (5 miles), Rickmansworth (9 miles), Harpenden (10 miles), St Albans (10 miles), Watford (10 miles). Just over the Buckinghamshire border, Chesham is about 4 miles away.
Choose an extension type
- Wraparound extensions · from £38,000
- Extensions over a garage · from £25,000
- Home office extensions · from £16,500
- Bungalow extensions · from £27,500
- Timber frame extensions · from £22,000
- Bedroom extensions · from £27,500
- Annexe extensions · from £58,000
- Single-storey rear extensions · from £22,000
- Flat roof extensions · from £22,000
- Conservatory replacement extensions · from £21,000
- Glass box extensions · from £31,500
- Side return extensions · from £19,000
- Kitchen extensions · from £28,500
- Utility and boot room extensions · from £14,500
- Double-storey extensions · from £40,000
- Orangery extensions · from £31,500
- Pitched roof extensions · from £23,500
- Planning permission for extensions · from £350
- Building regulations for extensions · from £950
- Side extensions · from £23,000
- Porch extensions · from £4,200
- Extension plans and drawings · from £1,250
Free site visit
A designer visits, takes measurements and photos, and discusses layouts, budget and timing with you.
Design and approvals
We draw the design, agree it with you and handle planning or permitted development checks and building regulations.
Fixed written price
You receive a written, itemised price and programme. Nothing starts until you are happy with it.
Build and sign-off
We build it with one project manager, book the building control inspections and hand over the completion certificate.
Questions about extensions in Berkhamsted
How much does an extension cost in Berkhamsted?
Using our East of England factor (×1.06), a standard-spec single-storey extension of 20 m² is a guide £43,000 to £55,500 including VAT, and a 32 m² two-storey extension £61,000 to £80,000. Your written price follows the survey.
Do you handle building regulations?
Yes. We prepare the drawings and calculations, submit them and book inspections, ending with a completion certificate.
Will my neighbours need to be told?
If you apply for planning or prior approval the council notifies them, and in England party wall notices may be needed for work near a shared boundary.
Can I get a price before anyone visits?
Yes. This page shows guide prices adjusted for Berkhamsted, and the guide-price tool gives a range for your own size and finish in about a minute.
How long does an extension take in Berkhamsted?
Usually 2 to 4 months of design and approvals, then 10 to 16 weeks on site for a single-storey extension or 16 to 24 weeks for two storeys.
Book a free site visit in Berkhamsted
We will measure up, check the planning position and give you honest guide figures.
- Free, no-obligation site visit
- Planning route checked before you spend on drawings
- Written price once the design is agreed
- Building control sign-off at the end
Prefer to talk? Call 0800 088 6341 or .
Book a free site visit
Tell us a little about the project and we will arrange a time.