Home office extensions for homes in Hemel Hempstead
From the first sketch to final sign-off, we plan and build home office extensions in Hemel Hempstead and the surrounding Hertfordshire area.
- Guide price in Hemel HempsteadFrom £16,500 inc VAT
- PlanningOften permitted development (3–4 m), or prior approval up to 6–8 m
- Build time8–12 weeks on site
- Postcode districtsAL3, HP1, HP2, HP3, WD4

How much does a home office extension cost in Hemel Hempstead?
Prices below are for Hemel Hempstead, using the East of England factor of ×1.06. They are guide ranges including VAT for the build only, not a quote.
Typical rates in Hemel Hempstead: £1,960 to £3,600 per m² including VAT, depending on specification.
| Size | Essential | Standard | Premium |
|---|---|---|---|
| 2.5 m × 3.2 m 8 m² | £16,500 – £20,500 | £18,000 – £23,000 | £22,500 – £29,000 |
| 3 m × 3.6 m 11 m² | £21,500 – £26,000 | £25,000 – £31,500 | £31,000 – £40,000 |
| 3 m × 5 m 15 m² | £29,000 – £35,000 | £34,000 – £43,000 | £42,500 – £54,500 |
Try the guide-price tool to see a range for your own size and finish.
Covering Hemel Hempstead
Our survey diary covers Hemel Hempstead, including AL3, HP1, HP2, HP3, WD4, WD5. Neighbouring towns we cover include Berkhamsted (5 miles), St Albans (5 miles), Harpenden (6 miles), Watford (7 miles).
Across the East of England many houses sit on generous plots, and single-storey and wraparound extensions are a natural fit.
What we take care of
- Heating or cooling sized for the room
- Data cabling and plenty of sockets
- Window and rooflight placement to avoid screen glare
- Sound insulation to the adjoining rooms
- Layout for desk, storage and video calls
Planning rules that apply in Hemel Hempstead
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.
Homes in conservation areas, national parks, National Landscapes (formerly AONBs), the Broads and World Heritage Sites have tighter rules, so we always check the property's status and planning history before design starts.
Building over or within 3 m of a public sewer needs the water company's consent, usually through a build-over agreement, before the foundations go in.
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).
Our process, step by step
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
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
We confirm the build price in writing, based on the approved drawings and the finishes you have chosen.
Build and sign-off
We build it with one project manager, book the building control inspections and hand over the completion certificate.
Home office extension questions answered
Do you cover all of Hemel Hempstead?
Yes. We cover Hemel Hempstead and the surrounding parts of Hertfordshire. Site visits are free and there is no obligation.
Will my neighbours in Hemel Hempstead be involved?
If a planning application or prior approval is needed, the council notifies neighbours. If the work is on or near a shared boundary, party wall notices may also be needed.
How long does a home office extension take to build in Hemel Hempstead?
On site, typically 8 to 12 weeks once approvals are in place. Before that, allow 4–10 weeks design and approvals.
Can I claim the cost against tax?
Building work on your home is not normally an allowable business expense, and claiming it can have capital gains tax effects. Speak to an accountant before assuming any tax relief.
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.
Book a free site visit in Hemel Hempstead
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.