Hartley, Kent
Single-storey rear extension in Hartley
Thinking about a single-storey rear extension in Hartley? Ground-floor space across the back of the house, usually for a kitchen, dining or family room. Our team handles the drawings, the planning route and the build, and your contract is with one company throughout.
Hartley sits in Kent, with postcode districts including DA3. On inter-war semis and 1960s estates like those around Hartley, a single-storey rear extension is usually the simplest way to fix a small back kitchen without touching the bedrooms.
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 single-storey rear extension cost in Hartley?
Guide prices for a single-storey rear extension in Hartley 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 |
We put a fixed price in writing once the design is agreed, and explain any provisional sums such as foundations.
Do you need planning permission for a single-storey rear extension in Hartley?
The planning route for a single-storey rear extension in Hartley is set by England's householder rules and your council.
English permitted development (Class A) allows a single-storey rear extension of 3 metres on a terraced or semi-detached house and 4 metres on a detached one, measured from the original house, with a maximum height of 4 metres and eaves of no more than 3 metres within 2 metres of a boundary.
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 Hartley like to extend?
Around Hartley 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 single-storey rear extension in Hartley 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.
Planning and regulations
We take the design through the right planning route, then produce the construction drawings and engineer's calculations for building control.
Build and sign-off
We build to the approved drawings with regular updates, then hand over the building control completion certificate and any guarantees from suppliers.
Single-storey rear extensions near Hartley
Close by, we work in Longfield, about 0.7 miles away, and Swanscombe, about 4.2 miles away.
- Single-storey rear extension in Longfield
- Single-storey rear extension in Swanscombe
- Single-storey rear extension in Gravesend
- Single-storey rear extension in Dartford
- Single-storey rear extension in Swanley
Other work in Hartley:
FAQ
Single-storey rear extension questions in Hartley
What postcode areas do you cover around Hartley?
Including DA3, and the surrounding Kent area.
Can you match the brick or stone on my Hartley house?
We source the closest match and show you samples before ordering; reclaimed materials are often the best match on older houses.
Does it add value to the house?
Nationwide's October 2025 house price research found that a 10% increase in floor area is linked to about 5% higher value on average. It is a guide, not a promise; local agents can tell you what extended homes on your street sell for.
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.
Do you handle building control in Hartley?
Yes. We apply to the council or a registered building control approver and hand over the completion certificate.
How much does a single-storey rear extension cost in Hartley?
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.