Single storey extensions planning facts - AJG Construction

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Single storey extensions planning facts

Published on Friday, 19th May 2017

Categories: Extensions

Single-storey extension

Adding a single storey extension to a home undoubtedly has many benefits for the property owner, and with the government recently loosening the rules and introducing wider permitted development guidelines, adding some much needed extra space to a property is now a more straight forward process.

However, it is important to consider that some local authorities might have different guidelines in place; when deciding to move forward with an extension, speaking with your local council, or a local construction firm should be a priority before proceeding with any plans.

Single storey extension guidelines/facts

The following guidelines currently apply to single storey extensions:

  • If the property is situated on designated land, then cladding the exterior is prohibited under permitted development. This includes artificial stone, render, plastic, timber and pebble dash.
  • A side extension does not come under permitted development if your property is on designated land.
  • Extensions must not cover more than 50% of the land of the original building. Existing extensions/outbuildings/sheds are incorporated into the size limit.
  • Exterior materials must blend in with the look of the building, however, these guidelines do not apply to
  • The width of a single storey side extension cannot exceed half of the original house.
  • Side extensions cannot be taller than 4 m
  • The height of the eaves on a side or rear extension must not exceed more than 3 metres if the extension comes “within 2 metres of a boundary”, according to government guidelines.
  • If the house is detached, then the new extension cannot exceed 4 metres past the back of the property; for attached properties, it must not surpass 3 metres from the rear of the house.
  • A single storey extension must not be more than 4 metres high
  • The eaves and ridge height of the new single storey extension cannot be taller than the existing property.
  • Some councils introduced new guidelines in 2013 regarding what would fall under a “permitted development”; check with your local authority in case these apply to your area.
  • Conservatory extensions were once limited to 4m from the rear of your home if the property is detached, and a 3m rule applied to other properties. However, recently introduced government guidelines mean conservatories can now be extended to 8 metres for a detached home and 6 metres for other homes.
  • The new rules for conservatories came into force in 2013 as part of the Neighbourhood Consultation Scheme and will remain in place until 2016.
  • Property owners who want to take advantage of the new guidelines for conservatories will need to contact their local planning authority to advise them of this.
  • Neighbours will be notified of your intention to build a conservatory of this size and they will have three weeks to raise objections to your plans.

Building Control

As with double storey extensions, Building Control guidelines will apply to a single storey extension. The floors, walls, insulation and other aspects of the new building must all be completed to Building Control standards; speak to a local construction firm who will be familiar with these guidelines to ensure that your project is completed to the required specifications.

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