Cosham, Hampshire
Wraparound extension in Cosham
We plan and build wraparound extensions for homeowners in Cosham. An L-shaped extension that fills the side return and runs across the back. Start with a free site visit, then a written price once the design is agreed.
Cosham is covered from our Hampshire round, including PO2, PO3 and PO6. In Cosham we usually draw the wraparound and a simpler rear-only option side by side, so the planning risk and cost difference are clear.
Book a free site visit
Tell us about the house and we'll call to arrange a free, no-obligation visit.
How much does a wraparound extension cost in Cosham?
In Cosham, our guide for a wraparound extension is £2,460–£4,030 per square metre including VAT for a standard specification. South East prices run above our West Midlands baseline, mainly on labour rates and clay-soil foundations.
| Size | Guide price inc VAT |
|---|---|
| L-shaped, about 22 m² of new floor | £54,000–£88,500 |
| L-shaped, about 30 m² of new floor | £74,000–£121,000 |
Ground conditions, glazing, the roof and how far the house is opened up move the final figure within the range.
Do you need planning permission for a wraparound extension in Cosham?
The planning route for a wraparound extension in Cosham is set by England's householder rules and your council.
Side return infills and the side leg of a wraparound are treated as side extensions in England: single-storey, no more than 4 metres high and no wider than half the original house. They are not permitted development in conservation areas, National Parks or National Landscapes, and a joined wraparound often needs a planning application because the side and rear rules apply together.
The Party Wall etc. Act 1996 applies in England: you serve notice two months before work to a shared wall, and one month before digging foundations within 3 metres (or 6 metres for deeper foundations) of a neighbour's building. Neighbours can agree in writing; if they dissent, surveyors agree an award.
Conservation areas, National Parks, National Landscapes and the Broads restrict permitted development, and listed buildings always need listed building consent. Before any drawing we look up the property's history with the council, because earlier extensions and removed rights change the answer.
What are homes in Cosham like to extend?
Cosham has a mix of Victorian terraces near the centre and larger Edwardian and inter-war houses further out. Clay soils across much of the South East mean deeper foundations near trees, which we plan for at the survey.
How a wraparound extension in Cosham comes together
Look round and measure
A free visit to see the back of the house, measure it, check the drains and boundaries and hear what you need.
Options and costs
We draw layout options and price each one, so the budget shapes the design rather than surprising you later.
Paperwork handled
Planning, prior approval or permitted development, Building Regulations approval, structural design and party wall notices are all handled by us.
Written price, then build
Once the design and approvals are in place, you get a fixed written price and programme, and we build through to sign-off.
Wraparound extensions near Cosham
Neighbouring places we cover include Waterlooville (2.8 miles) and Havant (3.5 miles).
- Wraparound extension in Waterlooville
- Wraparound extension in Havant
- Wraparound extension in Portsmouth
- Wraparound extension in Southsea
- Wraparound extension in Gosport
Other work in Cosham:
FAQ
Wraparound extension questions in Cosham
Is the site visit in Cosham free?
Yes. We visit, measure up and talk through the options with no cost and no obligation.
Will I need a structural engineer?
Yes for the beam over the new opening and usually the foundations; we arrange them and their calculations go to building control.
What roof suits a wraparound?
A flat roof with a lantern, a standing-seam pitched roof or a glazed roof over the side leg. The choice usually follows the first-floor windows above.
Can you match the brick or stone on my Cosham house?
We source the closest match and show you samples before ordering; reclaimed materials are often the best match on older houses.
How long does a rear extension take to build in Cosham?
Most single-storey rear extensions take 10 to 16 weeks on site and two-storey extensions 16 to 26 weeks, after design and approvals.
Do you handle building control in Cosham?
Yes. We apply to the council or a registered building control approver and hand over the completion certificate.