Thinking of extending your home - what are the planning rules?

18th July 2015

Thinking of extending your home - what are the planning rules?

By Kate Faulkner, Property Expert

If you can't decided whether to move or extend it's worth remembering the following planning conditions that could make it easier to extend you home. 

Should you do a loft extention or move house?

Are you consdiering a single story rear extention? 

A simple Check list below can help you determine what factors affect extensions to your home? 


  • National rules and regulations which apply to property extensions
  • Whether your property has been extended before
  • How big your garden area is
  • Whether your property is Listed
  • If your property is in a Conservation Area

National planning rules
Well, prior to 2013, this was fairly simple! However, since 30th May 2013 and until 30th May 2016 the rules have changed. The rationale behind the rule changes is to help encourage homeowners to spend more money on tradesmen and materials to help boost economic growth.

Be aware though, this rule change applies to England only. In the UK, housing laws are different for Wales, Scotland and Northern Ireland, sometimes they take on the schemes – such as Help to Buy, other times they don’t.

What is the rule change in England? 
Prior to May 30th 2013, the rules to extend your home were:-

Semi-detached and terrace properties, you could extend up to three metres

Detached homes, you could extend up to four metres

Now, in some cases, you can extend your property by:-

Up to six metres for a semi-detached and terrace property

Up to eight metres for a detached home

And you may be able to do this without having to go to the expense and time of securing planning permission. But the local authority will still have to secure permission via a ‘neighbourhood consultation scheme’.

Remember though, if you don’t need planning permission, even works as small as fitting a door with glazing, changing the electrics or drainage, may need sign off by the building regulations officer.

How can you tell if your property has been extended before? 
The reason you have to do this is because every home comes with something called ‘permitted development’ ie an amount the property can be extended by. Once this is eaten up by previous owners or yourself, you have to apply for planning if you want to make the home any bigger.

To check if a property has been extended is pretty simple. Most property types have a ‘similar’ footprint. 

Sometimes you can tell a property has been extended as the brickwork is plainly different or it has a flat roof rather than a pitched one.

If you really aren’t sure, then you can check with your local planning office and they will go through their files or even pop out to see you to clarify if your permitted development rights have been used.

How big your garden is
You might wonder why on earth the size of your garden is important. But it is. The reason being, whatever else the rules say, you can only extend your property to 50% of the size of the garden – typically the original size.

Is your property Listed? 
Whether you are buying or own a Listed property already, the rules are very different to any other type of property, in any area.

The key rule to know and understand for Listed properties is talk to your planners before you do anything at all. Different local authorities have different views on changing properties, and some are more strict than others, so you can only do what they allow you to