Wrap-Around Extensions
Maximum space. One seamless extension.
Wrap-around extensions combining side return and rear extension into one unified build. The most effective way to transform your ground floor layout in London terrace and semi-detached homes.
Wrap-around extension specialists in London.
A wrap-around extension combines a side return extension with a rear extension into a single, L-shaped build. This delivers significantly more usable floor space than either extension type alone and allows for a completely reimagined ground floor layout.
These projects are structurally more complex than a standard rear or side extension. They require careful structural engineering, often with multiple steel beams, and the coordination of foundations, drainage and roof detailing across two planes.
RCB manages every element — from the initial feasibility assessment and planning strategy through structural design, construction management and final handover. One team, one contract, one point of accountability for the entire build.
What's included
A wrap-around extension can add 20-30% more floor space than a rear extension alone
How It Works
The RCB process for this service.
Feasibility & Planning
We assess your property, the available space on both side and rear, planning constraints, and structural requirements for a combined wrap-around build.
Design & Engineering
Architectural drawings, structural calculations for the L-shaped configuration, planning application or Permitted Development confirmation, and Building Regulations submission.
Estimate & Contract
A detailed, itemised estimate covering foundations, steel, structure, roof, drainage, internal fit-out and all finishes. Clear scope, clear costs.
Build & Complete
Full construction management from site set-up through groundworks, steelwork, roof, external envelope, internal works and handover with Building Control certification.
Planning & Regulations
Wrap-around extensions may fall within Permitted Development depending on size and height — but the combined footprint often exceeds PD limits, requiring a full planning application. Properties in conservation areas or with Article 4 directions will almost always need planning permission. Building Regulations approval is mandatory. Structural calculations are essential given the complexity of the L-shaped steel configuration. Party wall notices will likely be required on both side and rear boundaries. RCB manages all approvals.
FAQs
Common questions.
What is a wrap-around extension?
A wrap-around extension combines a side return extension and a rear extension into one continuous L-shaped build. It wraps around the back corner of your property, creating a single large open-plan space. It is the most space-efficient extension type for London terrace and semi-detached houses.
Do I need planning permission for a wrap-around extension?
It depends on the combined size and your local planning constraints. Some wrap-around extensions fit within Permitted Development rights, but many exceed the size limits and require a full planning application. Properties in conservation areas will almost always need planning permission. RCB assesses this at the feasibility stage.
How much does a wrap-around extension cost?
Wrap-around extensions in London typically start from £55,000 and can reach £100,000+ depending on size, structural complexity, roof design, and specification. The structural engineering is more involved than a standard extension due to the L-shaped steel configuration. RCB provides a fully itemised estimate once the design is agreed.
How long does a wrap-around extension take?
A typical wrap-around extension takes 14–22 weeks on site. Pre-construction — design, planning, structural engineering, party wall and Building Regulations — adds 10–20 weeks depending on whether planning permission is required and the speed of your local authority.
Is a wrap-around extension worth it compared to a rear extension?
In most cases, yes. A wrap-around extension delivers 20–30% more usable floor space than a rear extension alone, and the additional cost of incorporating the side return is proportionally smaller than building it as a separate project later. It also avoids the disruption of two separate builds.
Trusted. Accredited. Verified.
Independently vetted by the UK's leading construction accreditation bodies
FMB
Federation of Master Builders
TrustMark
Government Endorsed Quality
Checkatrade
Vetted & Reviewed
TrustATrader
Trusted Trader Listed
Ready to discuss your project?
Book a free project review or send your drawings for a detailed estimate.