Planning Permission in Westminster: 2026 Guide

Planning in Westminster — what you need to know

If you are planning a home improvement project in Westminster, understanding the local planning landscape is essential before you begin. Westminster is managed by City of Westminster, which handles all planning applications, enforcement, and local plan policy for the borough.

Heritage-first planning approach; listed buildings on almost every street; basement and rear extension policies particularly strict. The borough has a population of approximately 205,000 residents and covers postcodes SW1, W1, W2, W9, NW1, NW8, WC2.

The housing stock in Westminster is predominantly grand Georgian and Regency terraces in Belgravia and Pimlico; Victorian and Edwardian mansion blocks; heritage-rich townhouses throughout; very high listed building density. This mix of property types means that Westminster City Council deals with a wide range of applications, from rear extensions on terraced houses to loft conversions on semi-detached properties and full refurbishments of period homes in conservation areas.

With 56 designated conservation areas and active Article 4 Directions, Westminster has a relatively controlled planning environment where Permitted Development rights may be restricted in many areas.

At Architectural Drawings London, we prepare planning drawings and building regulations drawings for properties across all Westminster postcodes. Our MCIAT chartered architectural technologists have experience with Westminster City Council and understand the specific policies, design guides, and precedents that apply in Westminster. Our fixed fees start from £840 for our Essentials package and £1,750 for our Complete package — 30% below typical London architect rates.

Article 4 Directions in Westminster

Westminster has Article 4 Directions in place that remove certain Permitted Development rights. Multiple Article 4 Directions — office-to-residential restrictions, HMO conversions, retail to residential in shopping zones.

Article 4 Directions are used by councils to protect the character of an area by requiring planning permission for changes that would otherwise be permitted. If your property is affected by an Article 4 Direction in Westminster, you will need to submit a full planning application even for works that would normally fall under Permitted Development. The council fee for a householder application is £258, and we prepare the necessary drawings and supporting documents.

It is important to note that Article 4 Directions in Westminster are separate from conservation area restrictions. A property can be affected by both, and in practice many Article 4 areas overlap with conservation areas. We check the specific restrictions affecting your property as part of our initial assessment.

Conservation areas in Westminster

Westminster has 56 designated conservation areas. Notable conservation areas include:

• Mayfair
• Belgravia
• Marylebone
• Pimlico
• Soho
• Covent Garden
• St John's Wood

In conservation areas, Permitted Development rights are more restricted than in non-designated areas. Key restrictions include:

• No cladding, stone, artificial stone, pebble dash, render, timber, plastic, or tile to any external wall without planning permission
• No side extensions under Permitted Development
• Rear extensions are limited and may require planning permission
• Dormer loft conversions facing the highway require planning permission
• Satellite dishes on front elevations or chimneys are not permitted
• Demolition of gates, walls, fences, or other boundary treatment requires planning permission

If your property is in a Westminster conservation area, we can advise on what is achievable and prepare a planning application that addresses the conservation officer's requirements. Our 98% first-time approval rate includes a strong record in conservation area applications.

Popular projects in Westminster

The types of planning applications most commonly submitted in Westminster are shaped by the borough's housing stock. Grand Georgian and Regency terraces in Belgravia and Pimlico; Victorian and Edwardian mansion blocks; heritage-rich townhouses throughout; very high listed building density, which drives demand for specific types of extensions and conversions.

Loft conversions

Westminster has extensive streets of terraced housing, making loft conversions one of the most popular home improvement projects in the borough. A rear dormer loft conversion on a typical Victorian or Edwardian mid-terrace can add 20-30 square metres of living space and significant value to the property. In many cases, rear dormers fall under Permitted Development rights, though properties in conservation areas or subject to Article 4 Directions will need full planning permission. We prepare loft conversion drawings for properties across Westminster, starting from £1,225 for our dedicated loft conversion package.

Side-return and rear extensions

The classic Victorian and Edwardian terrace layout in Westminster leaves a side return passage that is prime territory for a kitchen extension. A single-storey rear or side-return extension can often be built under Permitted Development, extending up to 6 metres from the rear wall (or up to 8 metres for detached houses under the Prior Approval process). We prepare extension plans for properties across all Westminster postcodes (SW1, W1, W2, W9, NW1, NW8, WC2), with our Essentials package starting from £840.

Flat conversions and internal alterations

With mansion blocks and converted flats forming part of Westminster's housing stock, internal layout changes and flat conversions are common projects. While internal alterations rarely need planning permission, converting a house to flats (C3 to C4 HMO) or vice versa may require planning approval, particularly given Westminster's Article 4 Direction covering HMO conversions. We can prepare the necessary floor plans, elevations, and supporting documents for flat conversion applications in Westminster.

Basement extensions

Basement extensions in Westminster are subject to specific planning policies. Westminster basement policy restricts to single-storey, typically under 50% of rear garden footprint; lightwells and rooflights strictly controlled in conservation areas. Despite these restrictions, basement conversions remain popular for adding living space in high-value Westminster properties where lateral or upward extension is limited. We prepare basement extension drawings that comply with Westminster City Council's policies, including structural methodology statements.

How much do planning drawings cost in Westminster?

The cost of a planning application in Westminster has two components: the council application fee and the professional drawing fees.

Our fixed-fee pricing means you know the cost upfront with no hourly billing surprises. We include a measured survey, existing and proposed plans, elevations, and a site plan — everything required for a valid planning submission to Westminster City Council. Our fees are 30% below typical London architect rates for the same scope of work.

For Permitted Development projects that do not require a planning application, we recommend obtaining a Lawful Development Certificate (£129 council fee). This provides formal legal confirmation that your project is lawful and prevents problems when selling the property. We prepare the LDC drawings and application on your behalf.

Our experience in Westminster

We cover all Westminster postcodes: SW1, W1, W2, W9, NW1, NW8, WC2. Whether your property is in a conservation area, affected by an Article 4 Direction, or in an unrestricted residential street, we have experience with Westminster City Council and understand the borough's planning policies.

Our MCIAT chartered architectural technologists prepare planning drawings and building regulations drawings for residential projects across Westminster. We handle the full process from initial measured survey through to planning submission, and we liaise with Westminster City Council on your behalf.

We also work in Westminster's neighbouring boroughs:

Frequently asked questions