Using Permitted Development Effectively

ABOVE: PD rights allow you to convert existing unused cellar space into habitable accommodation, but if you want to create a lightwell you’ll probably need to apply for planning permission. Basement extensions will also probably require planning — but the situation is evolving.

So what benefits can the existence of PD rights grant to a building plot, seeing as they only apply to an existing dwelling, once it is completed? Well, there’s no doubt that to simply demonstrate your knowledge of the existence of these rights can be a useful negotiating tool when dealing with planners. If the planners are pushing for a smaller dwelling and your PD rights are not impaired on the original Outline consent, you could ‘threaten’ to get the accommodation you need by extending at a later date or building outbuildings. And then you could offer the thought that perhaps it would be better to have a homogenous design rather than a hotchpotch of buildings.

If you are going for Full or Outline consent and the planners thought that your intention was to make things bigger by the use of PD rights, then they could insert a condition removing those rights. In that case it is better to keep your counsel.

One of the greatest benefits of PD is open to those engaged in building a replacement dwelling. In many cases, local authorities are concerned that any replacement dwelling either bears a size relationship to the existing dwelling or is no bigger than a certain percentage of the existing volume or footprint area. This figure will vary from council to council.

Let us take a case where the local authority has a policy prohibiting any new dwelling from being greater than 50% larger than the original. On the face of it, if you are buying a one-acre plot with a 100m² bungalow on it, you cannot build more than 150m². If you want more than that, by using PD rights you may get more — in one of three ways. You could argue that when the new bungalow is finished you would have the right to make it bigger, so why not do it at the beginning? But that could leave you open to a withdrawal of PD rights. You could extend the existing bungalow, occupy the roof space and build outbuildings. And then you could argue that it wasn’t after all a 100m² bungalow. But knocking down all those new works would be daft. So you carefully plan things and carry them out in a strict sequence:

Step One: You design a new bungalow that is 50% bigger than the original. This plan must swallow up the original bungalow and require its demolition.

Step Two: Having got planning permission, you put the plans aside.

Step Three: You then go back to the original bungalow and commence using up its PD rights by, for instance, building an extension, build ing a detached garage and building an out building as, say, a home office.

Step Four: Having built these, you then take out the planning permission for the new dwelling and demolish the existing bungalow, leaving the new structures.

Step Five: If you’ve designed things properly then, when you build the new bungalow, it will ‘fit onto’ the extensions and outbuildings and you’ll end up with an awful lot more than just the 50%.

Be very careful to do things in the right sequence. If you build the extension and outbuildings before you go for planning permission, then you will be rumbled and may be required to demolish them with the old bungalow.

To check whether your project needs approval under the new rules, visit the Government planning permission information website at planningportal.gov.uk.

Further reading:

• A Guide to the New Permitted Development Rules
• Planning Permission: Do I Have a Chance?
• Understanding Planning Permission