Home office extensions in Amersham: design, approvals and build
From the first sketch to final sign-off, we plan and build home office extensions in Amersham and the surrounding Buckinghamshire area.
- Guide price in AmershamFrom £17,500 inc VAT
- PlanningOften permitted development (3–4 m), or prior approval up to 6–8 m
- Build time8–12 weeks on site
- Postcode districtsHP6, HP7

Who a home office extension suits
- People who work from home most of the week
- Households that need a second quiet room
- Homes where a loft or garden room is not practical
North-facing glass and rooflights give steadier light for screen work. Where the office faces south, we use deeper reveals or external shading to keep glare and heat down.
How much does a home office extension cost in Amersham?
Prices below are for Amersham, using the South East England factor of ×1.12. They are guide ranges including VAT for the build only, not a quote.
Typical rates in Amersham: £2,070 to £3,810 per m² including VAT, depending on specification.
| Size | Essential | Standard | Premium |
|---|---|---|---|
| 2.5 m × 3.2 m 8 m² | £17,500 – £21,500 | £19,000 – £24,500 | £24,000 – £30,500 |
| 3 m × 3.6 m 11 m² | £22,500 – £27,500 | £26,000 – £33,500 | £33,000 – £42,000 |
| 3 m × 5 m 15 m² | £31,000 – £37,000 | £36,000 – £45,500 | £45,000 – £57,500 |
Try the guide-price tool to see a range for your own size and finish.
Planning and approvals in Amersham
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.
The planning position for a specific Amersham address depends on its history and any designations, which is why we check it at the first visit.
If the work involves a shared wall, building on the boundary, or digging foundations within 3 m (sometimes 6 m) of a neighbour's building, the Party Wall etc. Act 1996 applies and notice must be served before work starts: two months for work to a party wall, one month for new walls on the boundary and for excavations.
Applications are decided by the local planning authority (your district, borough or unitary council).
Extensions in and around Amersham
Postcode districts we cover around Amersham include HP6, HP7. The same team covers Chesham (2 miles), Chalfont St Peter (5 miles), Gerrards Cross (6 miles), High Wycombe (6 miles), all within easy reach.
Rickmansworth, in Hertfordshire, is roughly 6 miles from Amersham and also on our list. In the South East, plenty of houses have already been extended once, which makes checking the remaining permitted development allowance an important early step.
How the project works
Site visits are free and there is no obligation. Where drawings are needed, the design stage is priced in writing before it starts.
Free site visit
It starts with a visit to your house to measure, check access and talk through ideas and budget.
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
Our team builds the extension, keeps you updated weekly and finishes with building control sign-off.
Questions people ask about home office extensions
Can I see a price before committing to anything?
Yes. The guide prices on this page are adjusted for Amersham, and the guide-price tool gives a range for your own size. After the survey you get a written price before anything is agreed.
Who do I contract with for a home office extension in Amersham?
Your contract is with S&K Property Investments and Improvement Ltd, which designs and manages the project and the build teams who carry it out.
Do I need building regulations approval in Amersham?
Yes. Almost every extension needs it, whatever the planning route. We prepare the drawings and book the inspections.
Is an attached office better than a garden office?
An attached office shares the house heating and broadband, adds floor area to the home, and needs no garden path in the rain. A garden building can be cheaper and quicker but is a separate structure.
How much does a home office extension cost?
Our guide range is about £2,070 to £3,810 per m² including VAT. An 11 m² standard-spec office is typically £26,000 to £33,500 in Amersham.
Book a free site visit in Amersham
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.