Understand planning permissions for your own grand design as well as important information on local planning departments.

self build guide planning your grand design

Image: Tony Holt Design (01202 208 331; tonyholt-design.co.uk)


There are two types of planning permission – outline and full. Outline means you can build on the plot in principle; full permission describes exactly what can be built. If you’re working on a listed building or in a conservation area, you’ll need to make an additional application to get consent.

It can take up to eight weeks for the planning department to consider your application, and it also has the right to request longer. If your new-build has been refused, you can alter the proposal and resubmit it within 12 months for no extra charge. For changes to existing homes, such as extensions or loft conversions, you have 12 weeks to submit an appeal and the target period for a decision is eight weeks. If plans are approved you must start building within three years, otherwise the permission becomes invalid. Be sure to keep neighbours informed regarding your plans, and hire a chartered surveyor for party wall issues.

The planning department in your local area is responsible for approving all submissions and will also be able to provide you with advice. Planning applications need to be accompanied by detailed drawings and information, plus a fee will need to be paid, which will vary depending on the complexity of the plan and where you live. Go to planningportal.co.uk for more information and a fee calculator.


Permitted Development

If you’re thinking about extending or developing your property, one of the most important things to know is that going through your local planning department will almost certainly delay your project and is rarely straightforward.

Explore other options first and you may be able to achieve your goal within permitted development (PD), which allows you to make changes to your home without a planning application. There is a fixed cap on increasing the volume of your house, but in most situations PD is the easiest way to extend or refurbish. There are still procedures to follow, Building Regulations you must adhere to and also exemptions, so ensure you familiarise yourself with the latest policies (gov.uk).

PD applies only to houses, extensions to the rear of the building and loft conversions in some circumstances.

Your extension should not take up more than 50 per cent of the land surrounding the original property; sheds and outbuildings count towards this percentage.

The allowance takes into consideration any additions made since 1948.

Conservation areas, Areas of Outstanding Natural Beauty, World Heritage Sites and Sites of Special Scientific Interest are usually exempt from PD and rules apply to England only. Check with your local planning authority for more information.

There are additional rules on side extensions, proximity to boundary, eaves and materials, so always check the full criteria at planningportal.co.uk.


Project Checklist:

  • Plan ahead - Good contractors get booked up quickly and you will want toavoid building in winter, so make sure you arrange a good time slot.
  • The contract - Have everything agreed in writing, and remember to cover the project cost and how long it will take.
  • Money - Set a payment schedule for instalments to be paid as parts of the project are completed. Never hand over large sums of money up front.
  • Ground rules - Agree working hours with your builder, as well as facilities in your home they can use.
  • Be prepared - Clear the site, and keep children and pets away while construction is in progress.
  • Check your insurance - Major work on your home will affect your insurance, so talk through your plans with your provider.
  • Good neighbours - Inform your neighbours about how long the work will last and whether your contractors will need access to their property.
  • Keep talking - Most problems occur when there is a breakdown in communication. If you change your mind about something, tell your builder quickly and ask for an amended quote.
  • Garden matters - Consider landscaping as part of the project from the start.
  • Final payments - Settle up with every party once you’re entirely happy that the contract has been completed in full, including making good and removing all waste.

Words: Amanda Cochrane; Jo Messenger

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