• June


  • 149
  • 0
How Big an Extension Can I Build Without Planning Permission?

How Big an Extension Can I Build Without Planning Permission?

Expanding your living space with home extensions is more appropriate way to add value and practicality to your property. However, one of the main problems homeowners face is processing planning permission. The good news is that under certain conditions, you can build an extension without requiring formal approval. This article will explore the rules and guidelines for building an extension without planning permission, ensuring you can expand your home competently and legally. But in many cases an experienced consultant is required, you can hire a consultant from Plansing.

Understanding Permitted Development Rights

Permitted Development Rights (PDR) are a set of guidelines that allow homeowners to carry out certain building projects without needing to apply for planning permission. These rights cover various types of home extensions, provided they meet specific criteria. It’s important to note that PDR can vary between different local authorities, and some properties may have restrictions or have had their PDR removed.

Types of Extensions Under Permitted Development

  • Single Story Rear Extensions
  • Multi Story Rear Extensions
  • Side Extensions
  • Loft Conversions
  • Outbuildings
  • Single Story Rear Extensions

Single-story rear extensions are among the most common types of home extensions and often fall within Permitted Development Rights. For not creating confusions Plansing provides the best in the UK Planning Permission consultants

Key Guidelines:

  • Height: The maximum height of a single story rear extension should not exceed 4 meters.
  • Depth: The extension can extend up to 3 meters from the original rear wall for attached houses and 4 meters for detached houses.
  • Width: The width of the extension should not be more than half the width of the original house.
  • Design: The materials used should match the existing house.

Additional Considerations:

  • Neighbors: If the extension falls within close proximity to a neighbor’s boundary, it’s advisable to discuss your plans with them to avoid potential disputes.
  • Conservation Areas: In designated areas, such as conservation areas or national parks, stricter rules may apply.
  • Multi Story Rear Extensions

Multi-story rear extensions offer more space but come with stricter regulations under Permitted Development Rights.

Key Guidelines:

  • Height: The maximum height of a multi-story rear extension is 7 meters.
  • Depth: The extension can extend up to 3 meters from the original rear wall.
  • Proximity to Boundaries: Extensions should be at least 7 meters away from the rear boundary.
  • Windows: Upper floor windows should be obscure-glazed if they are on the side elevation.

Additional Considerations:

  • Impact on Neighbors: Due to their size, multi-story extensions can have a significant impact on neighbors’ light and privacy. Ensuring your plans are considerate of their space can help maintain good relations.

Side Extensions

Side extensions can transform unused side areas of a property into valuable living space.

Key Guidelines:

  • Height: The maximum height of a side extension should not exceed 4 meters.
  • Width: The width should not be more than half the width of the original house.
  • Design: Materials should be similar in appearance to the existing property.
  • Single Story: Side extensions should be single story only.
  • Still Confused: Contact Plansing for best in the UK service.

Additional Considerations:

  • Corner Plots: Properties on corner plots may have additional restrictions due to the potential impact on the street scene.

Loft Conversions

Loft conversions are a popular way to add an extra bedroom or office space without extending the footprint of your home.

Key Guidelines:

  • Volume: The maximum volume allowed is 40 cubic meters for terraced houses and 50 cubic meters for detached and semi-detached houses.
  • Height: The extension must not exceed the height of the existing roof.
  • Design: Materials used should be similar to the existing house.
  • Additional Considerations:
  • Roof lights and Dormer Windows: Adding roof lights or dormer windows must not extend beyond the plane of the existing roof slope on the principal elevation.


Outbuildings such as sheds, garages, and garden offices can also be built under Permitted Development Rights.

Key Guidelines:

  • Height: The maximum height is 4 meters for a dual-pitched roof or 3 meters for other types of roofs. If the building is within 2 meters of a boundary, the maximum height is 2.5 meters.
  • Size: The outbuilding should not cover more than half the area of land around the “original house.”
  • Usage: Outbuildings must not be used for residential accommodation.

For more guidelines hire an experienced Plansing consultant

Additional Considerations:

  • Proximity to Boundaries: Similar to other extensions, the impact on neighbors should be considered, especially regarding privacy and light.

Restrictions and Exceptions

While Permitted Development Rights provide considerable freedom, there are notable exceptions and restrictions:

Conservation Areas and Listed Buildings

Properties in conservation areas, national parks, or Areas of Outstanding Natural Beauty (AONB) typically have stricter rules. Additionally, listed buildings have their own set of regulations that must be adhered to, often requiring planning permission for any changes.

Article 4 Directions

Local councils can issue Article 4 Directions to remove Permitted Development Rights in specific areas, requiring homeowners to seek planning permission for developments that would otherwise be allowed.

Flats and Maisonettes

Permitted Development Rights generally do not apply to flats and maisonettes. Any extensions or alterations typically require planning permission.

Practical Steps to Ensure Compliance

Consult with Local Authorities

Before proceeding, it’s wise to consult your local planning authority. They can provide guidance and confirm whether your project falls within Permitted Development Rights.

Use Professional Services

Hiring an architect or professional builder from Plansing can help ensure your plans meet all necessary regulations and maximize the potential of your project.

Obtain a Lawful Development Certificate

A Lawful Development Certificate (LDC) is not mandatory but provides legal proof that your building works are lawful and do not require planning permission. This can be useful when selling your property.

Notify Neighbors

Keeping your neighbors informed about your plans can help avoid disputes and objections. Open communication can ease the planning process and foster good relationships.

Check for Other Restrictions

Ensure there are no covenants or other legal restrictions on your property that might affect your ability to extend your home.


Building an extension without planning permission is viable under Permitted Development Rights, allowing homeowners to expand their dwelling area without the lengthy and regularly steeply-priced method of acquiring formal approval. By expertise the specific criteria and recommendations for exclusive varieties of extensions, you could plan your venture hopefully and make sure compliance with local guidelines.

Whether you’re considering a unmarried-story rear extension, a loft conversion, or an outbuilding, taking the time to investigate and consult with Plansing professionals he will assist you are making the maximum of your own home’s capacity. Remember to recall the effect on your buddies, adhere to peak and length restrictions, and test for any extra policies that may follow to your private home.

By following these tips and leveraging Permitted Development Rights, you can create a practical and delightful extension that enhances your property and meets your needs.


Your comment will be published within 24 hours.