Covering Muswell Hill
Alongside Muswell Hill, we also cover Wood Green, Archway (2 miles to the south) and Finchley.
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 goes into 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 does a single-storey extension cost in Muswell Hill?
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 |
Planning and building rules in Muswell Hill
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 should I think about before starting?
- 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?
- Send us the details. Give us a postcode, a rough idea of size and some photos, by phone, form or the guide price tool.
- We visit and measure. A surveyor checks the house, the boundaries and the ground, and discusses what is realistic.
- Price and paperwork. The design is priced line by line, and we submit the planning and building control applications.
- Construction and completion. One site lead co-ordinates every trade through to the building control certificate.
Your questions answered
Do I need planning permission for a single-storey extension?
Often not in England, if the extension stays within permitted development limits: 3 m deep on an attached house or 4 m on a detached house, and no higher than 4 m. Larger ones need prior approval or a planning application. Wales, Scotland and Northern Ireland have their own rules.
Can we stay in the house during the build?
Usually yes. We keep the existing house closed off from the works until the knock-through near the end, and agree a temporary kitchen set-up with you if the kitchen is affected.
Can you visit a house in Muswell Hill to quote?
Yes. After a short call we arrange a site visit to measure up and agree what the design needs to do, then send a written price.
Single-storey extensions in nearby towns
- Single-storey extensions in Wood Green
- Single-storey extensions in Archway
- Single-storey extensions in Finchley
- Single-storey extensions in Holloway
Learn more about single-storey extensions, or see every project we cover in Muswell Hill.

