What Are The Planning Rules For A Granny Annexe In The UK?

Whether you have an elderly relative who you would like to provide more support for or you have adult children who would benefit from their own space while saving up to get on the property ladder, you may have considered a granny annexe.

These are an increasingly popular solution to the challenges modern families face when it comes to staying connected and providing the right level of support. 

It’s easy to see why a garden granny annexe might be appealing. For a start, it gives whoever will be living in it their own independence and freedom, while having family close by if needed. 

If you are considering this an option for an elderly relative, the cost of building a garden granny annexe will often be lower than the annual expense of care home fees, which is another reason why these are popular solutions.

This is especially true given that the average cost of care homes in the UK is over £1,200 week, sometimes exceeding £1,500 per week for those with more complex needs. 

But one question we often get asked is: “Do you need planning permission for a granny annexe in the UK?” 

The short answer is, “It depends.” But we’ll run through the main points to be aware of when deciding not only whether to build a granny annexe, but what type of annexe might suit you and your family. 

Do you need planning permission for a granny annexe in the UK?

The answer to this question depends largely on what kind of annexe you plan to build and where it will be constructed. 

In some cases, such as if you are converting a garage or another outbuilding that already exists on your property, you may be covered by permitted development rights. However, this will depend on where in the country you live. 

If you’re unsure, it’s always best to speak to a planning officer to find out whether your proposed annexe will be classed as a permitted development. 

Meanwhile, the granny annexes we construct do not require planning permission because legally they are considered to be mobile homes under the Caravan Act. 

This doesn’t mean they look like caravans – far from it. Simply that due to the way in which they are constructed and secured in place, it is possible to move them from one location to another on a trailer. 

The other way in which our annexes qualify under the Caravan Act is that they are in two parts, which are assembled onsite. 

How are two-part garden annexes assembled?

As part of our process, we will ensure your annexe is securely fitted in your garden using ground screws, which are quicker to install than traditional footings while remaining compliant with building control standards. 

Once the ground screws are in place, the steel frames will be delivered and assembled, providing a strong and durable frame around which the rest of the annexe is constructed according to your specifications. 

In addition to building the annexe itself, our team will also take care of connecting all the supply and waste connections for your garden annexe. This means you’ll have running water and electricity, as well as be hooked up to the sewage system. 

What are the planning rules for a granny annexe if you live in a designated area?

It is important to note that planning rules around the UK vary from region to region and in what are known as “designated areas” the rules may be different – particularly in relation to permitted developments. 

The locations that fall under this broad description include national parks, conservation areas, areas of outstanding natural beauty and World Heritage sites. In addition, the Norfolk and Suffolk Broads are also included in this designation.

You also need to be mindful that if you live in a listed building, the rules about what changes you can make in and around your property may also be different and could restrict what is possible. 

The best advice we can give you is to speak to a planning specialist before going ahead with any plans to build a granny annexe to ensure that this addition to your home is both legal and suited to your needs. 

What happens if I need planning permission for a granny annexe at my property?

If it turns out that you need to apply for planning permission to add a granny annexe at your home, our team can support you through this process to ensure it all moves smoothly. 

Planning permission may be required if you choose to design a bespoke annexe that puts it outside of the scope of what’s covered under the Caravan Act.