House Extensions
London & UK
SuperBuilder has been designing and building premium house extensions across London since 2001. We take care of everything — from planning permission and structural engineering through to the finished extension.
Our House Extensions Services
Rear Extensions
Extend into your rear garden for an open-plan kitchen-diner.
Side Return Extensions
Infill that narrow side passage for a wider ground floor.
Double Storey Extensions
Extend over two floors — bedroom upstairs, kitchen below.
Wrap-Around Extensions
Combine rear and side return for dramatic open-plan living.
Kitchen Extensions
Most extensions are kitchen-led — we work with your supplier.
Garage Conversions
Convert a garage into a habitable room — excellent ROI.
How It Works
Free Site Survey
We visit your property, assess the space, and discuss your goals.
Design & Planning
Our architects prepare drawings. We handle planning permission.
Fixed-Price Quote
A transparent, detailed quote. No hidden costs.
Build & Handover
We manage every trade — groundworks to finishes.
House Extensions Cost Estimator
Estimates are indicative only. Final costs depend on site conditions, specification, and access. Get a free, no-obligation quote for an accurate price.
What Our Clients Say
“SuperBuilder built our rear kitchen extension with a huge roof lantern. The steelwork was installed perfectly and the open-plan space has completely transformed how we use our home. Completed on time and within budget.”
James & Sarah M.Clapham, SW4 · Rear Extension“We went for a side return extension on our Victorian terrace. It has doubled the width of our kitchen. The seamless join between old and new is virtually invisible. Fantastic quality throughout.”
David & Helen T.Ealing, W5 · Side Return Extension“Double-storey extension giving us a new kitchen-diner and master bedroom above. SuperBuilder managed everything from planning to completion. Professional, tidy, and the result is stunning.”
Michael F.Bromley, BR2 · Double Storey Extension
Frequently Asked Questions
Ready to Extend Your Home?
Call us today for a free, no-obligation site survey and estimate.