Planning Permission in Merton: 2026 Guide

Planning in Merton — what you need to know

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

Wimbledon is heavily conservation-controlled; outer Merton (Morden, Mitcham) is permissive. The borough has a population of approximately 215,000 residents and covers postcodes SW16, SW17, SW19, SW20, CR4.

The housing stock in Merton is predominantly victorian villas in Wimbledon; Edwardian terraces in Tooting and Colliers Wood; 1930s semi-detached in Morden and Raynes Park; post-war flats in Mitcham. This mix of property types means that Merton 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 28 designated conservation areas and no current Article 4 Directions, Merton has a planning environment that balances heritage protection in conservation areas with generally permissive policies elsewhere.

At Architectural Drawings London, we prepare planning drawings and building regulations drawings for properties across all Merton postcodes. Our MCIAT chartered architectural technologists have experience with Merton Council and understand the specific policies, design guides, and precedents that apply in Merton. 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 Merton

Merton does not currently have any borough-wide Article 4 Directions that restrict Permitted Development rights for standard householder developments such as loft conversions, rear extensions, or outbuildings.

This means that most common home improvements in Merton can proceed under Permitted Development without needing to apply for planning permission, provided they meet the national criteria for size, height, and position. We recommend applying for a Lawful Development Certificate (£129) to formally confirm that your project qualifies as Permitted Development. This provides legal certainty and is valuable when selling the property.

Even without Article 4 Directions, properties in Merton's 28 conservation areas have additional restrictions on permitted development. We check the specific restrictions affecting your property as part of our initial assessment.

Conservation areas in Merton

Merton has 28 designated conservation areas. Notable conservation areas include:

• Wimbledon Village
• John Innes
• Mitcham Cricket Green
• Wimbledon Common

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 Merton 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 Merton

The types of planning applications most commonly submitted in Merton are shaped by the borough's housing stock. Victorian villas in Wimbledon; Edwardian terraces in Tooting and Colliers Wood; 1930s semi-detached in Morden and Raynes Park; post-war flats in Mitcham, which drives demand for specific types of extensions and conversions.

Loft conversions

Merton 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 Merton, starting from £1,225 for our dedicated loft conversion package.

Side-return and rear extensions

The classic Victorian and Edwardian terrace layout in Merton 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 Merton postcodes (SW16, SW17, SW19, SW20, CR4), with our Essentials package starting from £840.

Two-storey extensions

The semi-detached and detached housing stock in Merton is well suited to two-storey rear extensions, which almost always require planning permission. A two-storey extension can add a larger kitchen-diner at ground floor and an additional bedroom and bathroom above. Merton Council generally supports two-storey extensions that are subordinate to the original dwelling, set in from the boundary, and do not result in unacceptable loss of light or privacy to neighbours. Our Complete package from £1,750 covers full planning and building regulations drawings.

Flat conversions and internal alterations

With mansion blocks and converted flats forming part of Merton'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. We can prepare the necessary floor plans, elevations, and supporting documents for flat conversion applications in Merton.

How much do planning drawings cost in Merton?

The cost of a planning application in Merton 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 Merton 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 Merton

We cover all Merton postcodes: SW16, SW17, SW19, SW20, CR4. Whether your property is in a conservation area, affected by an Article 4 Direction, or in an unrestricted residential street, we have experience with Merton Council and understand the borough's planning policies.

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

We also work in Merton's neighbouring boroughs:

Frequently asked questions