Worked example

Side extension

A typical side extension, run through Plimbu. Here's the kind of planning outcome and cost estimate you'd see for a property like this.

This is an illustrative example based on a typical property — not an assessment of any specific address. Check your own property →

Illustrative side extension — Illustrative visualisation based on a Plimbu proposal — refined for clarity. Your own result may look slightly different.

What permission might I need?

England · Planning permission may be needed. The current proposal looks more likely to need a planning application than to rely on normal permitted development rights.

Planning permission Likely required
Building Regulations Required

What should I do next?

Planning Application Do this first
Building Regulations Do this first
Measured Drawings Recommended
Structural Engineer Recommended
Contractor Quotes Later

Indicative costs

Build £29,500–£43,500
Professional fees £2,500–£5,500
Statutory fees £500–£2,000
Contingency 15%
Overall estimate £37,500–£59,000 total

Costs and planning signals on example pages are illustrative only. Your property, constraints, and council area will differ. Use Check my property for a summary based on your address.