Westminster is one of the most controlled planning authorities in the country. The City of Westminster Plan and associated supplementary guidance cover almost every aspect of residential development, and the high concentration of listed buildings and conservation areas means that permitted development rights are rarely available in their standard form. The Basements SPD is actively applied, and flood risk in parts of the borough adds further complexity.
Common projects that may be straightforward when they fit within PD limits and local constraints.
These are the usual reasons planning permission becomes more likely in Westminster.
The biggest drivers of approval are the exact proposal (dimensions and design) and the exact site constraints (designation, conditions, neighbour impacts). Use borough context as a starting point, then validate it with address-level checks and nearby precedents.
Projects that stay modest in size, match materials, and avoid obvious neighbour impacts are more likely to be straightforward — even before you consider borough-specific policies.
Conservation areas, listed buildings, Article 4 directions, flood risk and TPOs can flip the answer. Address-level checks stop you wasting money on the wrong scheme.
The fastest signal is what the council has approved or refused on comparable streets nearby. Precedent does not guarantee success, but it helps you shape a lower-risk design.
Basement proposals are highly site-specific. Always validate with an address-level check and professional advice.
Check my propertyCouncils rarely refuse the “idea” of an extension or loft conversion — refusals are usually about scale, design, neighbour impacts, and policy/designation conflicts. When you run a check, CanUBuild shows nearby approvals and refusals so you can see what has worked locally.
An invalid application cannot be registered. Use this checklist to ensure your submission is complete before you pay the fee.
Requirements can change — always verify the current validation checklist on the Westminster Council website before submitting.
Search the address, choose your project type, and get an answer based on permitted development rules, local constraints, and nearby precedent decisions.
Effectively yes for visible external works. The high coverage of conservation areas and listed buildings means that most external changes — even minor ones like replacing windows or painting render — require either planning permission or listed building consent. Always check your specific constraints.
The SPD (October 2014) limits basement development to a single storey below ground in most cases, restricts garden excavation to approximately half the garden area, and requires detailed evidence on construction method, flood risk, and neighbour impacts. Multi-level basements are almost always refused.
Permitted development rights do still apply in Westminster for properties that are not listed, not in a conservation area, and not subject to specific Article 4 directions — but this describes a very small proportion of residential properties in the borough.
If the property is listed, listed building consent is required for any works that would affect the character of the building as a building of special architectural or historic interest — and this can include internal works like removing partitions, replacing doors, or altering original fabric.
Last reviewed: 2026-03 · This guide is for general information only. Always verify with Westminster Council or a qualified planning consultant before making decisions.