Single Storey Extension London

Expert design and planning for rear extensions, side returns, kitchen extensions and wrap-around designs across London. From concept to completion.

Types of Single Storey Extension

Rear Extensions

The most popular option for London homes. Extend your kitchen or living space into the garden with an open-plan layout. Many rear extensions qualify under permitted development, avoiding the need for planning permission.

Typical size: 3-8 metres deep. Cost: £40,000-£100,000.

Side Return Extensions

Ideal for Victorian and Edwardian terraced houses across London. Infill the narrow alley alongside your kitchen to create a wider, more usable space with improved natural light.

Typical width gain: 1-2 metres. Cost: £30,000-£60,000.

Kitchen Extensions

Transform your kitchen into the heart of your home. Open-plan kitchen-diners are the most requested design in London. We incorporate bi-fold doors, skylights and modern layouts.

Cost: £50,000-£120,000 depending on specification.

Wrap-Around Extensions

Combine a rear and side extension for maximum additional space. Wrap-around designs work particularly well on corner plots and end-of-terrace properties.

Typical gain: 20-40sqm. Cost: £70,000-£150,000.

Do You Need Planning Permission?

Usually Permitted Development

  • Rear extensions up to 3m (semi/terraced) or 4m (detached)
  • Extensions under 4m height at eaves
  • Not covering more than 50% of garden
  • Single storey, not forward of principal elevation

Planning Permission Required

  • ! Extensions exceeding permitted development limits
  • ! Properties in conservation areas
  • ! Listed buildings or Article 4 areas
  • ! Flats or maisonettes

Not sure? We provide a free permitted development assessment for every project.

Single Storey Extension FAQs

How much does a single storey extension cost in London?

Single storey extensions in London typically cost between £1,500 and £2,500 per square metre for construction, plus design fees of 8-15% of the build cost. A typical 4m x 5m rear extension might cost £50,000-£80,000 including design, planning and construction.

Do I need planning permission for a single storey extension in London?

Many single storey rear extensions in London fall under permitted development rights. You can extend up to 3 metres from the rear wall (6 metres with prior approval via a Larger Home Extension scheme, or 4/8 metres for detached houses). Side extensions, extensions in conservation areas, or those exceeding size limits require full planning permission.

How long does a single storey extension take from start to finish?

The full process typically takes 6-9 months. Design takes 4-6 weeks, planning permission (if required) takes 8 weeks, and construction takes 10-16 weeks depending on size and complexity.

What is the maximum size for a single storey extension without planning permission?

Under permitted development in London, you can build a single storey rear extension up to 3 metres deep (or 4 metres for detached houses) with a maximum eaves height of 3 metres. The extension cannot cover more than half the garden area and must not extend beyond the side wall facing a highway.

Will a single storey extension add value to my London home?

A well-designed single storey extension typically adds 5-10% to your London property value. In areas with high per-square-metre values, the return on investment can be significant, often exceeding the cost of the extension itself.

Single Storey Extensions Across London

We design single storey extensions across London and the surrounding 20-mile area. Our local knowledge of borough-specific planning policies gives your application the best chance of approval.

Ready to Start Your Single Storey Extension?

Free consultation. high planning approval rate. Call us today.

Call 020 3051 9430

Explore More House Extension Services

Discover our comprehensive range of house extension solutions across North London

Expert Team Available

Call now to speak with our expert team. Get instant responses and professional guidance for your extension project.

Instant ResponseExpert KnowledgeHuman Backup