Hastings, East Sussex
Semi-detached rear extension in Hastings
Semi-detached rear extension in Hastings: single or two-storey extensions for semi-detached houses, with side access and one party wall. We measure the house, show you what the rules allow, price it in writing and build it.
Hastings is covered from our East Sussex round, including TN34, TN35, TN37 and TN38. Semi-detached houses are common across East Sussex, and their side access makes rear extensions quicker to build.
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 semi-detached rear extension cost in Hastings?
Guide prices for a semi-detached rear extension in Hastings start from our South East England rate of £2,130–£3,470 per square metre, including VAT. South East prices run above our West Midlands baseline, mainly on labour rates and clay-soil foundations.
| Size | Guide price inc VAT |
|---|---|
| 3 m wide × 4 m deep (12 m²) | £25,500–£41,500 |
| 4 m wide × 5 m deep (20 m²) | £42,500–£69,500 |
| 4 m wide × 6 m deep (24 m²) | £51,000–£83,500 |
These are guide ranges; the written quote after the survey is the figure that counts.
Do you need planning permission for a semi-detached rear extension in Hastings?
Planning for a semi-detached rear extension in Hastings follows the English householder rules.
Under England's householder permitted development rules you can usually add 3 metres at the back of an attached house, or 4 metres on a detached house, without a planning application, as long as the extension stays under 4 metres high and its eaves stay under 3 metres where it is within 2 metres of a boundary.
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.
If 3 or 4 metres is not enough, England's prior approval route allows 6 metres on a terraced or semi-detached house and 8 metres on a detached house for a single-storey rear extension. Neighbours are consulted, the council decides within 42 days, and the fee is £249, rising to £310 from 8 December 2026.
Conservation areas, National Parks, National Landscapes and the Broads restrict permitted development, and listed buildings always need listed building consent. We check your house's planning history and any conservation area before drawing, so the route is clear before you spend on plans.
What are homes in Hastings like to extend?
Around Hastings the housing ranges from inter-war semis to 1960s and 1970s estates with good-sized gardens. Many of the newer estates had permitted development rights removed by condition, so we check the planning history before anything is drawn.
How a semi-detached rear extension in Hastings comes together
Survey visit
We visit free of charge, measure up, check access, drainage and neighbours' extensions, and note what you want the room to do.
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.
Semi-detached rear extensions near Hastings
Neighbouring places we cover include St Leonards-on-Sea (1.5 miles) and Bexhill-on-Sea (4.8 miles).
- Semi-detached rear extension in St Leonards-on-Sea
- Semi-detached rear extension in Bexhill-on-Sea
- Semi-detached rear extension in Hailsham
- Semi-detached rear extension in Eastbourne
- Semi-detached rear extension in Seaford
Other work in Hastings:
FAQ
Semi-detached rear extension questions in Hastings
Do you handle building control in Hastings?
Yes. We apply to the council or a registered building control approver and hand over the completion certificate.
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.
How long does a semi extension take?
10 to 16 weeks on site for a single-storey extension.
What postcode areas do you cover around Hastings?
Including TN34, TN35, TN37 and TN38, and the surrounding East Sussex area.
How much does a semi-detached rear extension cost in Hastings?
As a guide, £2,130–£3,470 per square metre including VAT for a standard specification. For example, 3 m wide × 4 m deep (12 m²): about £25,500–£41,500 at that rate. Your written price follows the 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.