Prior approval drawings in Westminster

The council's guidance for roofs and mews

Westminster's published advice includes two documents that matter even when prior approval is open: the Roofs: a guide to alterations and extensions on domestic buildings SPG and the Mews: a guide to alterations SPG. The first governs additions at roof level on domestic buildings, the second the particular character of mews houses.

Neither document governs a prior approval, which has its own narrow tests. They do tell us how the council reads a building in context, and where an owner falls back on a householder application they set the standard for design.

The local plan was adopted in 2,026, so these documents now sit beside brand-new policy, and we check the current status of both on the day we start.

Heritage that shapes every Westminster project

Beyond conservation areas, the borough holds 28 registered parks and gardens and 23 entries on the Heritage at Risk register. A house beside one may find its setting weighed in any application.

Domestic gardens cover just 7.9 per cent of the land, so for houses the plot rarely allows a deep extension even where the rules would.

A terraced house averages £1,616,250 and a semi-detached one £2,760,923, so the cost of drawings is small against the value at stake, and an incorrect route is expensive.

What householders in Westminster usually need instead

Westminster decided 366 householder applications in the latest twelve months and granted 82 per cent, with 79 per cent decided on time. For most owners, that is the realistic route, supported by drawings that show how the scheme sits within the conservation area.

Where a house is outside every designation, the larger extension depth limits are 6 m (attached) / 8 m (detached), single storey, height max 4 m; not on article 2(3) land or an SSSI, the LPA notifies adjoining owners/occupiers, giving at least 21 days for representations, and there is a deemed decision after 42 days.

The council also recorded 138 lawful development certificate applications, so proving ordinary rights is common.

Information the council expects for a conversion

For a commercial-to-residential notification the council expects a site plan, floor plans of each new home with room sizes, a description of the change and evidence of the previous use. We prepare these together so the file is complete at submission.

We also check the building against local heritage layers, because a listed or locally important building needs separate consent for alterations whatever the prior approval says.

Some Westminster premises sit in mixed-use buildings, where the ground floor is a shop and the upper floors are already homes. In that case we confirm exactly which part of the building the conversion covers, and we draw the separate entrance, bin and cycle stores and the stair arrangements that the officer will want to see are safe for new residents.

Daylight to the new rooms and noise from neighbouring commercial uses are points the Order asks the council to consider, so we address both in the covering note before they are raised.

Choose the right route for a Westminster address

Start with a Lawful Development Certificate in Westminster if the work looks permitted, or planning drawings in Westminster for an application. If the project is a change of use, our change of use drawings explain the wider picture.

Our architectural drawings in Westminster page lists the rest, and neighbouring pages include prior approval drawings in Camden and prior approval drawings in Brent.