Loft conversion drawings in Westminster from £625

56 conservation areas, eight with Article 4 rights removed

Westminster says there are 56 conservation areas, and that it has removed permitted development rights in eight of them, so planning permission is required for specified minor alterations there. The council gives an interactive map for checking an address.

For example, a house inside one of the eight areas may need an application for a roof change that a similar house outside them could build under permitted development, with a lawful development certificate to prove it. We confirm the route in writing before drawing, so you do not pay for a set built on the wrong assumption.

Mansard loft drawings

What Westminster’s householder checklist asks for

The householder page says plans and drawings must carry a scale bar so that electronic measurements can be made, and typically include existing and proposed floor plans, elevations and sections. It adds: “You will need to provide roof plans if you are doing works to the roof.” Related plans should be combined into as few files as possible.

A design and access statement is required where you are in a conservation area and the building has 100 square metres or more of floor space, or the house is listed. Photographs are required where the proposal affects a conservation area or listed building. Fire statements are asked for on major development under the London Plan, not on a house loft.

Timing and CIL in Westminster

Westminster decided 123 of 186 householder applications inside eight weeks in the year to June 2026, so a clean, valid first submission matters more here than almost anywhere.

Westminster’s CIL has three zones, Prime, Core and Fringe, and generally applies from 100 square metres of new floor area. For permissions granted in 2026 the indexed residential rates are £811.80, £590.40 and £295.20 per square metre, plus Mayoral CIL in band 1. A loft inside the existing roof is normally under the threshold.