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 Swanley?
In Swanley, a wraparound extension typically costs £2,450–£3,600 per m² of floor area, including VAT at 20% (standard rate). For a typical 28 m² project that is roughly £68,500–£101,000. The guide for Swanley reflects typical costs in the South East, roughly 12% above the UK-wide figure. Design, structural calculations and council fees are extra.
| Size or type | Guide range |
|---|---|
| Smaller project (20 m²) | £49,000–£72,000 |
| Typical project (28 m²) | £68,500–£101,000 |
| Larger project (39 m²) | £95,500–£140,500 |
| Rate per m² | £2,450–£3,600 |
The main things that change the cost:
- Access for materials on terraced streets
- Total footprint and the amount of glazing
- Drainage changes
- Kitchen and flooring specification
Your exact price depends on the survey and drawings. The guide price tool gives a quick range in the meantime.
Do you need planning permission for a wraparound extension in Swanley?
Whether you need planning permission depends on your house and its location 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.
Our first visit includes a check of your planning history, so you know the route before paying for drawings.
What we handle
Handled as part of most wraparound extensions:
- Walls, roof and glazing
- Party wall notices and surveyor liaison
- Underfloor heating option, electrics and plastering
- Building control completion
- Design and planning application
- Structural engineer’s design for steels and supports
How long does it take?
Allow 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 Swanley
Commuter towns across the South East have many 1930s and post-war semis that suit rear extensions and hip-to-gable loft conversions.
If your home is in Swanley or close by in Orpington, Sidcup and Dartford, a free home visit is the first step.
How it works
- 01
Free visit
We look at the property, talk through what you want and measure up. There is no charge and no obligation.
- 02
Design and fixed quote
Drawings, structural calculations and an itemised, fixed price for the agreed specification.
- 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 Swanley
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.
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.
How long does a wraparound extension take in Swanley?
Typically 12 to 18 weeks on site. Design and approvals beforehand usually take 3 to 4 months.
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.
How much does a wraparound extension cost in Swanley?
In Swanley, a wraparound extension typically costs £2,450–£3,600 per m² of floor area, including VAT at 20% (standard rate). A typical 28 m² project comes to roughly £68,500–£101,000. Your fixed price depends on the survey and drawings.