Home office extensions across Dorset
Our design and build teams take on home office extensions in Dorset, from the first measured survey through planning and building control to the finished room.
- Guide priceFrom £16,000 inc VAT
- PlanningOften permitted development (3–4 m), or prior approval up to 6–8 m
- Towns covered9
- Site visitFree, no obligation

Towns in Dorset
Home office extension prices in Dorset
For Dorset we adjust our national guide rates by ×1.02, the factor we use for South West England. Figures include VAT; your written quote after the survey replaces them.
Typical rates in Dorset: £1,890 to £3,470 per m² including VAT, depending on specification.
| Size | Essential | Standard | Premium |
|---|---|---|---|
| 2.5 m × 3.2 m 8 m² | £16,000 – £19,500 | £17,500 – £22,500 | £22,000 – £28,000 |
| 3 m × 3.6 m 11 m² | £20,500 – £25,000 | £24,000 – £30,500 | £30,000 – £38,500 |
| 3 m × 5 m 15 m² | £28,000 – £34,000 | £32,500 – £41,500 | £41,000 – £52,500 |
For a figure based on your own dimensions, use our guide-price tool.
What we take care of
- Window and rooflight placement to avoid screen glare
- Data cabling and plenty of sockets
- Heating or cooling sized for the room
- Sound insulation to the adjoining rooms
- Layout for desk, storage and video calls
Will the council need to approve it?
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 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.
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.
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.
Applications are decided by the local planning authority (your district, borough or unitary council).
Covering Dorset
Towns we cover in Dorset include Bournemouth, Poole, Weymouth, Christchurch, Dorchester, Wimborne Minster, Bridport, Ferndown. South West homes range from terraced streets in the cities to stone cottages and bungalows in the countryside, and conservation areas are common in historic centres.
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
First, a site visit: we look at the house, garden, access and drains and listen to what you need.
Design and approvals
We produce the drawings and structural design, and manage the approvals so they are in place before work starts.
Fixed written price
With the design and specification agreed, you get a fixed written price and a start date.
Build and sign-off
We build it with one project manager, book the building control inspections and hand over the completion certificate.
Common questions in Dorset
Do you cover all of Dorset?
Yes, across the whole of Dorset. Site visits are free and there is no obligation.
Who do I contract with for a home office extension in Dorset?
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.
Will my neighbours in Dorset 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.
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.
How much does a home office extension cost?
Our guide range is about £1,890 to £3,470 per m² including VAT. An 11 m² standard-spec office is typically £24,000 to £30,500 in Dorset.
Book a free site visit in Dorset
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.