Free tool · England & Wales · 2026 rules
Do I need planning permission?
Most home projects fall under permitted development and need no application — but a handful of limits catch people out: height, front elevations, conservation areas and flats. Answer five questions for an indication in seconds.
Answer five questions
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Answer all five questions to see an indication.
The limits that decide it, in 2026
- Rear extension depth: 3m terraced and semi-detached, 4m detached.
- Overall height: 4m maximum; 3m at the eaves within 2m of a boundary.
- Nothing forward of the principal elevation facing a road.
- Loft volume: 40m³ terraced, 50m³ semi-detached and detached.
- Outbuildings: single storey, no more than half the garden covered.
- No permitted development rights for flats and maisonettes.
Common questions
- Do I need planning permission for a single-storey rear extension?
- Often not. A single-storey rear extension up to 3m deep on a terraced or semi-detached house (4m detached) and no more than 4m high is normally permitted development. Larger extensions up to 6m and 8m can be possible under the prior approval neighbour consultation route.
- Do I need planning permission for a loft conversion?
- Most loft conversions are permitted development if the added volume stays within 40m³ for a terraced house or 50m³ for a semi-detached or detached house, nothing extends beyond the front roof slope, and side windows are obscure-glazed.
- How much does a planning application cost in 2026?
- A householder application in England is around £258, a lawful development certificate around £129, and a prior approval notification around £120. Drawings and any consultant fees are extra.
- What happens if I build without permission?
- The council can require changes or removal, and the absence of approval will surface when you sell. If work is already done, a certificate of lawfulness or a retrospective application is the route back.
Plan the whole project, not just the permission
Renovome sets out your scope, a realistic programme including approvals, and a shortlist of matched professionals who can confirm your route.