Rear House Extensions in Barnet & North London.
Transform your ground floor with a beautifully designed single or double-storey rear extension — fully managed from planning to handover.
Rear house extensions across Barnet and North London
A rear house extension is one of the most popular home improvement projects in North London — and one of the most transformative. By extending the back of your property, you can create a larger kitchen, an open-plan kitchen-diner, a family room, a home office or a utility room. Single-storey rear extensions are the most common type we build across Barnet, Finchley, Mill Hill, Hampstead and the surrounding areas. Most single-storey rear extensions fall under Permitted Development rights — meaning no planning permission is required, provided the extension meets the national size and design criteria. We assess Permitted Development eligibility for every client as part of our free site visit.
What's included in our rear extension service?
Our fully managed service covers every aspect of your rear extension — from initial design and structural engineering through to roofing, glazing, electrics, plumbing and plastering. We handle all Building Regulations submissions and manage every trade on site. You have one dedicated project manager from day one and receive weekly written updates throughout. Typical inclusions: structural engineer drawings, Building Regulations application and inspections, foundations and groundworks, masonry or steel frame construction, roof structure and covering (flat, pitched or glazed lantern), bi-fold or sliding doors, first fix electrics and plumbing, plastering and basic finishes.
Common questions
Do I need planning permission for a rear extension in Barnet?
Most single-storey rear extensions in Barnet fall under Permitted Development and don't require planning permission, provided they meet size limits (typically 3m for semis/terraces, 4m for detached). Extensions between 3–6m (semis) or 3–8m (detached) require a Prior Approval application. Conservation area properties always need planning permission. We handle all of this for you.
How much does a rear extension cost in Barnet?
A typical single-storey rear extension in Barnet and North London costs between £35,000 and £65,000 depending on size and specification. Use our Online Price Guide for an instant estimate.
Can I extend at the rear and the side at the same time?
Yes — a wrap-around extension combines a rear extension with a side return, creating a much larger addition. This is one of our most popular projects and is often more cost-effective than doing both separately.
How much will your project cost?
Get an instant cost estimate for your extension, loft conversion, renovation or new build — tailored to your project in under 60 seconds.
Ready to extend your home in Barnet?
Book a free, no-obligation consultation. We'll visit your home, listen to your brief and tell you honestly what's possible.
Or message us directly on WhatsApp — we typically respond within the hour.