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Wraparound extensions in North London
Wraparound Extensions
Rear and side extensions combined into one L-shaped ground floor — the biggest transformation short of a new house.
A wraparound extension combines a rear extension and a side (or side return) extension into a single L-shaped addition that wraps around the back corner of the house. It delivers the largest ground-floor space of any extension type — typically 30–45 m² — and allows a kitchen, dining and living area to be planned as one room with the garden on two sides.
Because it exceeds what permitted development allows for the side element, a wraparound almost always needs a planning application; we design it to be approvable first time.
Who this suits
- Semi-detached and end-of-terrace houses with a side passage and a rear garden
- Families who want a large open-plan kitchen-dining-living space
- Houses where the original rooms will be repurposed (utility, snug, study) rather than removed
- Projects where the extra width unlocks a better layout than a deep rear extension alone
Planning position
Permitted development treats rear and side extensions separately and does not allow them to be combined into one wraparound structure, so a householder application is normally required (fee £258 in England; eight-week determination). What councils look at: the depth of the rear element relative to neighbours' windows (the "45-degree" daylight test), the height and eaves line of the side element, the width of the remaining side gap, and materials. In conservation areas the side element is scrutinised more closely. A well-composed roof — often a flat roof with a parapet, or a pitched roof over the side wing — and a modest depth on the neighbour's side usually secure approval.
Structure
Removing both the rear and side walls of the original house at ground floor leaves the corner of the building supported on steel: a beam along each line meeting on a column or a moment-connected "goalpost" that keeps the corner column-free. The engineer also checks the first floor and, where a chimney breast is removed, the chimney above. Foundations, drainage diversions and build-over agreements follow the same logic as a rear extension but on a larger footprint, and the site is more exposed to weather during the structural phase, so sequencing matters.
Layout: making a big room work
An L-shaped room needs zones — a kitchen run along the side wing, dining at the junction, living space towards the garden — and daylight from more than one direction: rooflights over the side wing, glazing on the rear, and a window at the far end of the side wing. Ceiling heights can vary between the two wings to define the zones. Keep the utility room and a WC near the side wing where the drainage is. We design the kitchen and joinery with the architecture, not after it.
Cost guide · figures current as of September 2026
What wraparound extensions cost in North London
| Item | Typical range | Notes |
|---|---|---|
| Wraparound extension, 30–45 m² | £100,000 – £180,000 | |
| Steel frame and structural opening of two elevations | £15,000 – £35,000 | Included in the above; shown to explain why per-m² rates are higher than a rear extension |
| Glazing package (doors, windows, rooflights) | £15,000 – £40,000 | |
| Kitchen and utility, supply and fit | £20,000 – £55,000 | |
| Design, engineering, planning and Building Regulations | 8 – 12% of build cost |
North London market ranges excluding VAT, fees and the kitchen unless stated. A wraparound is the most cost-effective route to a large ground floor, but the structural phase is the most variable part of the estimate.
What could your wraparound extensions project cost?
Use our project calculatorSources: Architecture for London — extension costs 2026; Planning Portal — extensions. Market guides only — not a Milkov & Son quotation.
How long it takes
- 01Design and planning4–6 months
- 02On site14–20 weeks
Stages overlap where they can. We agree a programme in writing before work starts — see how a project runs.
Frequently asked questions
Does a wraparound extension need planning permission?
Almost always, because permitted development does not allow rear and side extensions to be joined into one structure. A householder application takes eight weeks to determine once validated.
How much does a wraparound extension cost in North London?
Typically £100,000 to £180,000 for 30–45 m² in 2026, excluding VAT, professional fees and the kitchen.
How long does a wraparound take to build?
14 to 20 weeks on site is typical, after four to six months of design and planning.
Is a wraparound better than a rear extension?
If you have a side passage and want a large, wide room, usually yes: more space for the money and daylight from two sides. If your priority is speed and permitted development, a rear extension is simpler.
Read before you build
Extensions
Rear Extensions vs. Wraparound Extensions: What’s the Difference?
A rear extension adds depth; a wraparound adds depth and width by including the side return, creating an L-shaped room. Space, light, planning (PD versus application), cost and disruption compared for North London houses.
23 July 2025 · 6 min read
Extensions
The Biggest Advantages of Adding a Rear or Wraparound Extension
In many London homes, especially those in terraced or semi-detached areas, space can feel limited. Families grow, lifestyles evolve, and what once felt like…
5 November 2025 · 7 min read
Design & Architecture
The Pros and Cons of Open-Plan Living Spaces
Open-plan living spaces have surged in popularity over the last few decades, becoming a hallmark of modern home design. For many homeowners, the appeal lies…
22 April 2025 · 6 min read
Wraparound Extensions across North London
Based in Hendon, we work across North London and the Hertfordshire border. Each area page covers the local housing stock, planning context and the kind of work we do there.
All areasRelated services
House Extensions
Rear, side return, wraparound, double storey and kitchen extensions — designed, approved and built by one team.
Design & Build
Feasibility, design, approvals and construction under one contract, with one person accountable for the result.
Loft Conversions
Dormer, hip-to-gable, L-shaped and mansard conversions that add a bedroom and bathroom without touching the garden.
Architectural Design & Planning
Feasibility, concept design, planning applications and Building Regulations drawings, priced with construction in mind.
Discuss your project
Discuss a wraparound extensions project
Send a few details about the property, what you want to achieve and your approximate budget. Stoyan reads every enquiry and replies within one working day.
What happens next: a short call, a site visit if it is a good fit, then a written proposal. No charge, no obligation.