Planning permission is often required if you are looking to extend the overall footprint of your house; however, there are some exceptions. These such projects fall under the classification of Permitted Development (PD).

PD is implied consent for the work that is to be carried out. If you are looking to add a little extra space without going for a massive extension or applying for planning permission, then take a look at our list of PD information and its legal requirements and restrictions.

However, if you live in a conservation area or a listed building, there may be higher limitations to what works you can do under PD.

For all types of property development, it’s worth checking with your local authority or a planning expert beforehand. Get in touch today for help with planning applications in Cornwall.

Can I Build An Extension Without Planning Permission?

You can add a single or double-storey extension providing you adhere to specific requirements; this type of extension is a good way to add space onto existing rooms.

For example, a two-storey extension could add kitchen/dining room space downstairs while extending the master bedroom upstairs.

The restrictions for a single-storey extension are:

  • The extension must not sit forward of the principal elevation (the front of the house).
  • The materials used must be similar to that of the existing house.
  • If it is within two meters of a boundary, the eaves (overhanging edges of the roof) must not be higher than three meters.
  • Rear extensions must be no more than four meters in-depth for a detached house and three meters for a semi-detached or terrace house.
  • Side extensions must not be bigger than half the width of the original building.

If you were wanting to build a two-storey extension without planning permission then the above restrictions apply as well as:

  • The extension must be built at the rear of the property. This includes adding a second storey onto an already existing single storey.
  • The extension much be no closer than seven meters to the rear boundary (if it is closer than seven metres to the rear boundary then you will need planning permission)
  • The extension must not exceed three meters beyond the rear wall of the original house.

A man designing a building plan

Can I Convert My Loft Without Planning Permission?

Loft conversions can be useful for adding a decent amount of floor space to an existing house. Under PD, you cannot raise the height of the roof, so an existing decent sized loft will be needed.

Generally, under PD, a space of up to 40m² is allowed. To provide extra headspace, you can add dormer windows, providing they do not reach higher than the existing roof.

a loft converted into a sitting room

Can I Build an Outbuilding Without Planning Permission?

Outbuildings are separate structures to the main dwelling. These include:

  • Garages.
  • Garden sheds.
  • Greenhouses.
  • Summer houses.
  • Saunas.
  • Kennels.

You can build an entirely new outbuilding providing it will not be used as self-contained living accommodation or have an antenna. Other criteria for outbuildings include:

  • Outbuildings must only be a single storey.
  • Outbuildings must not cover an area of more than 50% of the total land of the house. This includes any existing outbuildings but does not include the area covered by the main house.
  • Depending on the type of roof, there are height limitations.
  • The highest allowed is a four-meter dual pitch roof.
  • If the building is within two meters of the boundary, the height restriction is two and a half meters.

Existing outbuildings may also be eligible for conversion under PD. If the outbuilding is attached to the house, for example, a garage with a connecting door can be converted as long as you do not extend the footprint of the house.

Please be aware that a standalone outbuilding will need permission of a different type.

Can I Build a Porch Without Planning Permission?

Porches are usually small and do not require planning permission, however, you must remember that:

  • The porch cannot be taller than three meters.
  • If the boundary is adjacent to a highway, it must not be within two meters of the porch.
  • The external ground area must be three m2 or less.

A proch with a black front door

This guide is a useful start to planning any works for your home without having to apply for planning permission.

If you would like to read more about types of planning permission, check out our article.

When do I need planning permission?

Martin Perry Associates offers structural design for a range of house works including loft conversions and extensions. For more information on structural engineers in Exeter and the West Country, please don’t hesitate to get in touch.

Contact us today