Single-Storey Rear Extension with Garden Room
A 4m single-storey rear extension under Permitted Development — designed, scanned, and specified in under 3 weeks.
The challenge
What they were facing.
A young family needed more living space but had a tight budget and wanted to avoid a lengthy planning process. The rear garden was large enough for an extension, but they were unsure what they could build without planning permission.
Our solution
How we helped.
We confirmed the extension fell within Permitted Development limits (under 4m for a single storey). We completed the design, 3D scan, structural calculations, and Certificate of Lawfulness in 3 weeks. The client was introduced to a vetted builder from our network who started on site within a month.
Lessons learned
What this project taught us.
- Permitted Development can be faster than most homeowners realise — no 8-week wait.
- Getting a Certificate of Lawfulness (not just assuming PD applies) protected the homeowner at resale.
- Trade-price materials saved the client roughly 15% compared to retail pricing.
Value added
The impact.
From first enquiry to builder on site in under 8 weeks. The Certificate of Lawfulness gives the homeowner legal proof of compliance — essential for mortgage lenders and future buyers.
“I was dreading the whole planning process. PlanBuild made it feel like ordering something online — choose what you want, pay a fixed price, and it just happens.”
Ready to start your project?
Professional plans from £250. No obligation, no follow-up calls.