We'd been putting off the extension conversation for years. caniextend gave us a clear answer in ten minutes — and the cost estimate was remarkably accurate.
AI-powered extension planning for UK homeowners
Could your home fit
an extension?
Upload your floorplan. Get a professional extension proposal, cost estimate, and planning guidance — in minutes.
Early access: 50 homeowners + 10 estate agents
RIBA-aligned guidance
UK planning regulations checked
Results in under 5 minutes
From floor plan to proposal in minutes
No architect needed. No waiting weeks. Upload your floorplan and get a complete proposal in under five minutes.
Upload your floorplan
Take a photo of your property's floorplan — estate agent brochure, architect drawing, or a hand sketch. We accept PDF, JPG, and PNG.
Our AI analyses your property
We cross-reference your floorplan with UK planning rules, your property boundaries, and local authority records to identify your extension options.
Extension Proposal
24 Clarence St, SE15
Estimated cost£62k–£74k
Planning routePermitted Dev.
Build time10–14 weeks
Permitted Development
Get your extension proposal
In minutes you receive a complete extension design, cost estimate, planning compliance check, and comparison with similar properties nearby.
What homeowners say
Used it before making an offer on a property. Checked extension potential without paying for a surveyor. Saved me from a costly mistake.
The planning compliance check was worth it alone. Knowing our rear extension fell under Permitted Development gave us real confidence to proceed.
Everything you need to plan your extension
No more paying thousands for a feasibility study. Get the same quality insight in minutes.
Extension design
A scaled architectural drawing of your proposed extension, showing the new layout alongside your existing floorplan.
Planning compliance check
We check your extension against Permitted Development rights and local planning rules — so you know before you build.
Cost estimate
A realistic cost breakdown based on current UK build rates, your location, and extension type — updated quarterly from RICS data.
Neighbour comparison
See what similar extensions nearby have been approved for, with actual costs and planning outcomes from Land Registry.
Early access
Your home has more potential
than you think
Join the waitlist and be among the first to find out if you can extend.