Covering Eltham
Eltham sits 9 miles south-east of London, with Blackheath 2 miles to the north-west and Welling 3 miles to the east.
Homes in London
Terraced houses dominate many London neighbourhoods, so most projects involve shared walls, narrow access and a party wall process. Conservation areas are widespread, and some boroughs have their own mansard and basement guidance.
What is a single-storey extension?
A single-storey extension adds one level of new floor space to the back or side of a house, usually to open up a kitchen, dining or family room. It is the most common way to gain space without moving, and many can be built without a planning application.
- Measured survey and design drawings
- Planning or lawful development certificate where needed
- Brickwork, roof, glazing and insulation
How much should I budget for a single-storey extension?
Indicative costs for single-storey extensions. London and the South East usually sit towards the top of each range.
| Single-storey extensions | Guide price incl. VAT |
|---|---|
| Standard specification | £2,600 to £3,000 per m² |
| Good specification | £3,000 to £3,500 per m² |
| High specification | £3,500 to £4,000 per m² |
Do you need permission for a single-storey extension in Eltham?
Projects in England go through two separate checks. Planning (or confirmation that the work is permitted development) comes from the district, borough or unitary council, and building regulations approval comes from the council’s building control team or a registered building control approver. Where work touches a shared wall or digs near a neighbour’s foundations, the Party Wall etc. Act 1996 applies.
In England a single-storey rear extension can often go ahead under permitted development: up to 3 m deep on an attached house or 4 m on a detached one, no higher than 4 m, with eaves no higher than 3 m within 2 m of a boundary. Deeper extensions, up to 6 m or 8 m, need prior approval from the council first.
What can affect a single-storey extension?
- Building on or near a shared boundary usually means serving a party wall notice in England and Wales.
- Large glazed areas need to meet energy rules, which can shape the size of doors and rooflights.
What are the steps?
- Tell us about the project. Call, use the guide price tool or send the form with a few photos and a postcode.
- Free site visit. We measure up, look at access, drains and the structure, and talk through options and budget.
- Drawings, approvals, written quote. We prepare the design, apply for the approvals it needs, and give you a fixed price in writing.
- Construction and completion. One site lead co-ordinates every trade through to the building control certificate.
Questions about a single-storey extension in Eltham
How much does a single-storey extension cost?
Most single-storey extensions cost about £2,600 to £4,000 per square metre including VAT, depending on specification, glazing and ground conditions. We give a fixed price in writing for the agreed specification after the survey.
How long does a single-storey extension take to build?
The build itself usually takes 10 to 16 weeks once work starts on site. Design, approvals and ordering usually add 6 to 12 weeks before that.
How do I get a price for single-storey extensions in Eltham?
Use the guide price tool for a ballpark figure, then book a visit for a fixed written price for the agreed specification.
Other towns nearby
- Single-storey extensions in Blackheath
- Single-storey extensions in Welling
- Single-storey extensions in Catford
- Single-storey extensions in Greenwich
Learn more about single-storey extensions, or see every project we cover in Eltham.

