Covering Blackheath
We work in Blackheath (SE3) and the places around it, including Greenwich, Catford and Eltham.
Homes in London
Much of London’s housing is Victorian and Edwardian terraces, which is why side return extensions, rear dormers and mansards are so common. Many streets are in conservation areas, and several boroughs use Article 4 directions that remove some permitted development rights.
What does a single-storey extension involve?
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
- Building control application and inspections
- Foundations, drainage and structural steel
How much does a single-storey extension cost in Blackheath?
What single-storey extensions typically cost. These are guide ranges; the written quote for your house replaces them.
| 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 Blackheath?
In England we deal with the council’s planning team for permission or a lawful development certificate, with building control (the council or a registered building control approver) for inspections, and with neighbours under the Party Wall etc. Act 1996 where it 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 change the price or programme?
- Large glazed areas need to meet energy rules, which can shape the size of doors and rooflights.
- Kitchens and doors have long lead times, so we order them early.
How does the project run?
- Start with a conversation. A short call or the online form is enough for us to understand what you want to build.
- 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.
What people ask before starting
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.
Will the brick match?
We source the closest available match for colour, size and texture and agree a sample panel with you before laying.
Who deals with the council for a project in Blackheath?
We do. We prepare the drawings, submit planning or permitted development paperwork if needed, and arrange building control inspections.
Single-storey extensions in nearby towns
- Single-storey extensions in Greenwich
- Single-storey extensions in Catford
- Single-storey extensions in Eltham
- Single-storey extensions in Peckham
Learn more about single-storey extensions, or see every project we cover in Blackheath.

