Do I need planning permission for a loft conversions in Westminster City Council?
Typical answer
In most cases, loft conversions in Westminster City Council fall under Permitted Development rights (Part 1 Class B), meaning no planning application is needed, subject to Article 4 restrictions, conservation-area flags, and the specific thresholds below. If your property is in a conservation area, Article 4 area, or involves a listed building, additional restrictions apply and you should verify your position before starting work.
Source: Part 1 Class B — legislation.gov.uk · Verified 2026-04-19
Free five-minute check. No account needed.
Permitted Development rules
Part 1 Class B thresholds
These are the key numerical limits under Part 1 Class B of the General Permitted Development Order 2015. Your project must satisfy all of them to qualify as Permitted Development.
| Clause | Rule | Limit |
|---|---|---|
| B.1(d) | Added volume cap | Terraced (m³): 40; Other (m³): 50 |
| B.2(b) | Side-facing windows must be obscure-glazed and non-opening below 1.7 m | Openable above (m): 1.7 |
| Source: Part 1 Class B — legislation.gov.uk | ||
Westminster City Council planning data
Local planning facts
Approval rate
0.8%
Below average for householder applications
Source: MHCLG Planning Statistics (PS2)
Planning application fee
£548
Householder application (national fee)
Reviewed April 2026 · gov.uk source
Submission portal
Portal link not yet listed for Westminster City Council. Use the national Planning Portal.
Other project types in Westminster City Council
Get a verdict for your specific property
The rules above apply nationally. Your assessment checks your specific address against Article 4 directions, conservation area boundaries, and listed building status — in under five minutes.
Check my specific property →Free assessment · Optional LDC letter add-on