Planning permission and building regulations explained

London planning for houses

Some people find the difference between planning permission and Building Regulations approval confusing, so we thought we’d do a quick overview of each in this blog post. We’ll also look at when you need planning permissions and how to go about getting Building Regulations approval for your loft conversion or extension.

Planning Permission

Planning permissions exist to help guide the way our towns, cities and countryside develop, including how land and buildings are used, the appearance of buildings, landscaping considerations, highway access and the impact that the development will have on the general environment.

Loft conversions are often covered by permitted development rights and in this case won’t need planning permission. There are exceptions however.

If your extension or conversion fits the following criteria then you probably won’t need planning permission:

  • The additional space won’t be larger than and area of 40m3 for terraced houses or 50m3 for semi-detached or detached houses. This also includes the space from any previous addition you have made.
  • The extension doesn’t reach further than the outermost end of the existing roof slope of the front of the house.
  • The extension doesn’t go higher than the highest part of the existing roof.
  • Roof extensions are set back at least 20cm from the original eaves and as far back as is practical (unless it is a hip-to-gable roof extension).
  • The roof enlargement doesn’t overhand the outside face of the original wall.
  • There are no verandas, balconies or raised platforms.
  • Side-facing windows are frosted or patterned to prevent anyone seeing inside and are at least 1.7m above the floor.
  • Your property isn’t on designation land, such as in a Conservation Area, an Area of Outstanding National Beauty, World Heritage site, etc.
  • Your house isn’t a listed building.

It’s best to confirm with your architect or builder or the local council whether you need planning permission or not, before proceeding with any works. It can take a while to get planning permission, so factor this into your timescale.

Building Regulations

Building Regulations set standards for building design and construction to safeguard people and their health whilst in or around buildings. They also cover the conserving of fuel and power and what facilities are provided for people (e.g. those with disabilities) to access and get around inside buildings.

Although the majority of loft conversions can be carried out without planning permission, they will still have to satisfy Building Regulations. This is to ensure that the building work is structurally sound (for instance new floor joists might be required to support the weight of the new loft conversion) and that sound is reasonably insulated between the loft and rooms underneath it. Building Regulations will also require that the new extension or conversion is fire safe, for example with fire-resistant doors and mains-powered smoke alarms as well as a suitable staircase for means of escape (ladders or retractable staircases won’t be sufficient).

Your architect and/or builder should be ensuring that these requirements are met and get Building Regulation approval for the works at the completion of the project.

Find out how Cox Format can help you with regard to getting the relevant permissions and approvals for your loft conversion or extension.

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