What is a wraparound extension?

A wraparound extension combines a side return and a rear extension into one L-shaped addition. It gives the largest possible ground floor, often creating an open-plan kitchen, dining and living space across the whole width of the house.
How much does a wraparound extension cost in Orpington?
In Orpington, a wraparound extension typically costs £2,850–£4,150 per m² of floor area, including VAT at 20% (standard rate). For a typical 28 m² project that is roughly £80,000–£116,000. We start from a UK-wide guide and adjust it for London, where labour and materials are typically about 30% above average. Design, structural calculations and council fees are extra.
| Size or type | Guide range |
|---|---|
| Smaller project (20 m²) | £57,000–£83,000 |
| Typical project (28 m²) | £80,000–£116,000 |
| Larger project (39 m²) | £111,000–£162,000 |
| Rate per m² | £2,850–£4,150 |
The biggest cost drivers are:
- Steelwork and propping of the existing house
- Total footprint and the amount of glazing
- Party wall surveyor fees for one or both neighbours
- Kitchen and flooring specification
Use the guide price tool to see how size and specification change the figure, then ask for a written, itemised quote.
Do you need planning permission for a wraparound extension in Orpington?
The approval route for Orpington is set by planning law in England. In England a wraparound extension combines side and rear elements, which normally takes it outside permitted development, so a householder planning application is made.
Where work involves a shared wall, building on the boundary, or digging foundations within 3 metres of a neighbour’s building and deeper than its foundations (or within 6 metres for deeper work), the Party Wall etc. Act 1996 applies and notices must be served before work starts.
At the survey we check your house’s planning history and any restrictions, and tell you which route applies.
What we handle
Handled as part of most wraparound extensions:
- Removal of internal and external walls
- Building control completion
- Walls, roof and glazing
- Design and planning application
- Structural engineer’s design for steels and supports
- Foundations and drainage
How long does it take?
The build itself usually takes 12 to 18 weeks on site. Before that, surveys, drawings and approvals usually take 3 to 4 months, longer if the council asks for changes.
Building in Orpington
Many London boroughs have conservation areas and detailed design guides, so early design advice saves time at the planning stage.
We work across Orpington and neighbouring areas such as Sidcup, Swanley and Bromley. Postcodes we cover in Orpington include BR6.
How it works
- 01
Survey and brief
We visit, discuss your ideas and budget, and survey the property or site at no cost.
- 02
Drawings and written quote
We prepare the design and give you a written, itemised quote with inclusions and exclusions.
- 03
Approvals in place
We handle planning, building control and neighbour notices before work starts.
- 04
Construction and completion
We build, put right any snags and hand over the building control certificate.
Questions about wraparound extensions in Orpington
How much does a wraparound extension cost in Orpington?
In Orpington, a wraparound extension typically costs £2,850–£4,150 per m² of floor area, including VAT at 20% (standard rate). A typical 28 m² project comes to roughly £80,000–£116,000. Your fixed price depends on the survey and drawings.
How long does a wraparound extension take in Orpington?
Typically 12 to 18 weeks on site. Design and approvals beforehand usually take 3 to 4 months.
Does a wraparound extension need planning permission?
Almost always. Combining side and rear elements usually goes beyond permitted development limits, so a householder planning application is normally made.
Will both neighbours be affected?
Usually only the neighbour on the side return side, but rear foundations near either boundary can trigger party wall notices.
Is a wraparound worth it?
It gives the biggest ground-floor space without going upwards. Whether it adds value depends on your street and house, so we suggest checking local sale prices before committing.
