Dorchester, Dorset
Two-storey rear extension in Dorchester
We plan and build two-storey rear extensions for homeowners in Dorchester. A larger kitchen downstairs and an extra bedroom or bathroom upstairs, under one roof. Start with a free site visit, then a written price once the design is agreed.
Dorchester sits in Dorset, with postcode districts including DT1. Two-storey rear extensions suit semi-detached houses in Dorchester best, where the extra bedroom matters as much as the bigger kitchen.
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 two-storey rear extension cost in Dorchester?
A two-storey rear extension in Dorchester is priced at £1,870–£2,810 per square metre including VAT as a guide, before kitchen fit-out and fees. South West prices run slightly above our West Midlands baseline; natural stone to match the house is the main variable.
| Size | Guide price inc VAT |
|---|---|
| 3 m × 5 m footprint, two floors (30 m²) | £56,000–£84,000 |
| 4 m × 6 m footprint, two floors (48 m²) | £90,000–£135,000 |
Your written price follows a measured survey and an agreed design, so it reflects your house, not an average.
Do you need planning permission for a two-storey rear extension in Dorchester?
Planning for a two-storey rear extension in Dorchester follows the English householder rules.
A two-storey rear extension can be permitted development in England only if it projects no more than 3 metres, stays at least 7 metres from the rear boundary, matches the existing roof pitch and has obscure-glazed upper side windows. In practice most double-storey rear extensions go through a householder planning application.
Conservation areas, National Parks, National Landscapes and the Broads restrict permitted development, and listed buildings always need listed building consent. Before any drawing we look up the property's history with the council, because earlier extensions and removed rights change the answer.
What are homes in Dorchester like to extend?
Dorchester has Victorian terraces nearer the centre and post-war semis on the edges. Sloping gardens are frequent, which affects floor levels and steps down to the patio.
How a two-storey rear extension in Dorchester comes together
Look round and measure
A free visit to see the back of the house, measure it, check the drains and boundaries and hear what you need.
Design and guide price
Two or three layout options with a guide price for each, so you choose the design knowing what it costs.
Paperwork handled
Planning, prior approval or permitted development, Building Regulations approval, structural design and party wall notices are all handled by us.
Written price, then build
Once the design and approvals are in place, you get a fixed written price and programme, and we build through to sign-off.
Two-storey rear extensions near Dorchester
Neighbouring places we cover include Weymouth (7.2 miles) and Portland (10.3 miles).
- Two-storey rear extension in Weymouth
- Two-storey rear extension in Portland
- Two-storey rear extension in Bridport
- Two-storey rear extension in Blandford Forum
- Two-storey rear extension in Yeovil
Other work in Dorchester:
FAQ
Two-storey rear extension questions in Dorchester
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.
Will I need a structural engineer?
Yes for the beam over the new opening and usually the foundations; we arrange them and their calculations go to building control.
Will we need to move out?
Rarely. The first-floor opening is made late in the job and sealed with temporary screens.
Is the site visit in Dorchester free?
Yes. We visit, measure up and talk through the options with no cost and no obligation.
Can I live at home while the extension is built?
Usually yes. Most of the work is outside until the back wall is opened near the end, and that stage is screened off.
Do I need planning permission for a rear extension in Dorchester?
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.