Wraparound extensions for homes in Harrow
We design and build wraparound extensions for houses in Harrow, with a written price once the survey and design are done and one point of contact throughout.
- Guide price in HarrowFrom £46,500 inc VAT
- PlanningUsually a householder application
- Build time14–20 weeks on site
- Postcode districtsHA0, HA1, HA2, HA3, HA7
Extensions in and around Harrow
Our survey diary covers Harrow, including HA0, HA1, HA2, HA3, HA7, HA9. The same team covers Wealdstone (1 mile), Wembley (2 miles), Pinner (2 miles), Northolt (3 miles), all within easy reach.
Just over the Hertfordshire border, Bushey is about 5 miles away. In London, space is at a premium and gardens are often short, so side returns, wraparounds and carefully planned rear extensions tend to make the most of every metre.
Wraparound extension prices in Harrow
These guide figures apply our London adjustment (×1.3) to national rates. They include VAT at 20% and cover the build itself; design and council fees are listed separately.
Typical rates in Harrow: £2,600 to £4,810 per m² including VAT, depending on specification.
| Size | Essential | Standard | Premium |
|---|---|---|---|
| Compact L-shape 18 m² | £46,500 – £56,500 | £53,500 – £68,000 | £67,500 – £87,000 |
| Medium L-shape 25 m² | £65,000 – £78,000 | £74,500 – £94,500 | £94,000 – £120,500 |
| Large L-shape 32 m² | £83,000 – £100,000 | £95,500 – £121,000 | £120,500 – £154,000 |
Want a range for your exact size? The guide-price tool takes about a minute.
What is included
- Roof with glazing along the side return
- Householder planning application
- Party wall notice support (England and Wales)
- Structural design for the corner and openings
- Full internal finish or kitchen-ready shell
- Survey, design and 3D layout options
The corner is where wraparounds succeed or fail. We usually use a single steel goalpost or a corner post hidden in a pier, and set the glazing so the new room reads as one space rather than two boxes.
Planning rules that apply in Harrow
In England a wraparound extension is assessed as both a side and a rear extension, and the combination usually falls outside permitted development, so most need a householder planning application (£548 from 1 April 2026).
Before any drawing is finalised we check whether the house is listed, in a conservation area or subject to an Article 4 direction.
Building regulations approval is separate from planning. In England you can use the council's building control team or a registered building control approver; a full plans application gets the drawings checked before work starts, and the inspector signs the work off with a completion certificate.
If the work involves a shared wall, building on the boundary, or digging foundations within 3 m (sometimes 6 m) of a neighbour's building, the Party Wall etc. Act 1996 applies and notice must be served before work starts: two months for work to a party wall, one month for new walls on the boundary and for excavations.
Applications are decided by the local planning authority (your district, borough or unitary council).
Our process, step by step
Site visits are free and there is no obligation. Where drawings are needed, the design stage is priced in writing before it starts.
Free site visit
It starts with a visit to your house to measure, check access and talk through ideas and budget.
Design and approvals
Once the layout is agreed, we deal with the council: planning permission or written confirmation that none is needed, plus building control.
Fixed written price
You receive a written, itemised price and programme. Nothing starts until you are happy with it.
Build and sign-off
We build it with one project manager, book the building control inspections and hand over the completion certificate.
Wraparound extension questions answered
Who do I contract with for a wraparound extension in Harrow?
Your contract is with S&K Property Investments and Improvement Ltd, which designs and manages the project and the build teams who carry it out.
How long does a wraparound extension take to build in Harrow?
On site, typically 14 to 20 weeks once approvals are in place. Before that, allow 8–16 weeks design and approvals.
Do I need building regulations approval in Harrow?
Yes. Almost every extension needs it, whatever the planning route. We prepare the drawings and book the inspections.
Is a wraparound better than a side return alone?
It adds far more space, but costs more and needs planning permission more often. Our comparison guide sets the two side by side.
How much does a wraparound extension cost?
Our guide range is about £2,600 to £4,810 per m² including VAT. A 25 m² standard-spec wraparound typically lands around £74,500 to £94,500 in Harrow before design and council fees.
Book a free site visit in Harrow
We will measure up, check the planning position and give you honest guide figures.
- Free, no-obligation site visit
- Planning route checked before you spend on drawings
- Written price once the design is agreed
- Building control sign-off at the end
Prefer to talk? Call 0800 088 6341 or .
Book a free site visit
Tell us a little about the project and we will arrange a time.