Covering Blackheath
Alongside Blackheath, we also cover Greenwich, Catford (2 miles to the south-west) 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 do you get with a side return extension?
Side returns are small in area but heavy in detail: party walls, a glazed roof, and steelwork to take out the original back wall. We design the roof for light and drainage, agree the party wall process early, and keep the work tidy because access is often through the house.
- Party wall notices and surveyor liaison
- Structural steel to remove the side wall
- Underfloor heating ready screed if wanted
How much does a side return extension cost in Blackheath?
Indicative costs for side return extensions. London and the South East usually sit towards the top of each range.
| Side return extensions | Guide price incl. VAT |
|---|---|
| Standard specification | £3,350 to £3,700 per m² |
| Good specification | £3,700 to £4,150 per m² |
| High specification | £4,150 to £4,550 per m² |
What approvals does a side return extension need in England?
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.
What can change the price or programme?
- Access is often through the house, so we plan deliveries and protect floors.
- Many terraces sit in conservation areas, where side extensions need planning permission.
From first call to completion
- Start with a conversation. A short call or the online form is enough for us to understand what you want to build.
- 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.
- We build it. Work follows an agreed programme, with inspections at each stage and a final sign-off.
Your questions answered
Does a side return need planning permission?
In England it can be permitted development if it is single storey, no higher than 4 m and no wider than half the original house. Conservation areas are the main exception.
How long does a side return take?
About 10 to 14 weeks on site.
Do you work in Blackheath?
Yes. Blackheath is within our coverage for side return extensions, along with nearby Greenwich and Catford.
Other towns nearby
- Side return extensions in Greenwich
- Side return extensions in Catford
- Side return extensions in Eltham
- Side return extensions in Peckham
Learn more about side return extensions, or see every project we cover in Blackheath.