Planning Permission for London House Renovations: A Practical Guide

Planning permission is one of the subjects that causes most anxiety for London homeowners embarking on a renovation. In practice, many projects do not require formal planning consent — but knowing when you do, and when you don't, is genuinely complicated. This guide aims to cut through the confusion.

Permitted development rights

Most domestic improvements in England can be carried out under "permitted development rights" — a set of national rules that allow certain types of work without requiring a planning application.

Permitted development typically covers:

• —Single-storey rear extensions (subject to size limits)
• —Loft conversions (subject to volume limits)
• —Internal alterations (changing room layouts, removing non-structural walls)
• —Reroofing with similar materials
• —Installation of most windows and doors

The size limits and conditions can be complex. Crucially, permitted development rights can be restricted or removed entirely if your property is in a conservation area, an area of outstanding natural beauty, or is a listed building.

When you always need planning permission

• —Side extensions visible from the street
• —Extensions to flats (flats have no permitted development rights at all)
• —Any work to a listed building that affects its character (this requires Listed Building Consent, not standard planning)
• —Work in a conservation area that affects the external appearance of the building
• —Basement conversions (almost always require planning in central London boroughs)

London's tougher planning environment

London boroughs tend to apply planning rules more strictly than many other parts of England. Westminster, RBKC, Camden and the City of London in particular have additional local policies that restrict certain types of development.

Conservation areas cover a large proportion of inner London. If your property is in one, you should check with your architect before assuming permitted development applies.

The prior approval process

Some projects fall between full permitted development and full planning permission — they require "prior approval" from the council. This is a lighter-touch process but still requires a formal application and the council's agreement before work starts.

Larger single-storey rear extensions (over four metres for a detached house, or over three metres for other houses) typically require prior approval.

Our approach

At ASAAN, every project starts with a clear view of the planning position. Our architectural team carries out a planning assessment as part of the initial brief, so you know exactly what is and is not achievable before you commit to a design.

If a planning application is required, we manage the full process — drawings, heritage statements, consultation with officers, submission and follow-up. We have a strong track record with London's most demanding planning authorities.

If you are planning a renovation and want to understand where you stand on planning, get in touch and we can talk it through. You may also find our guides on loft conversions and house extensions useful.