Building a Granny Annexe

Adding an extension on to your home is a great way to create more space and increase the value of your property, but with so many different ways to add extensions it’s difficult to decide the best option for your home. This article looks into the granny annexe and the benefits of building one on your property.

The Granny Annexe

A granny annexe is a single story accommodation built on your property that typically consists of an open plan lounge and kitchen, 1 or 2 bedrooms and a wet room. The granny annexe received it’s name based on its intended purpose: to provide a supported, yet still independent, living space for an elderly relative. In recent years, however, the granny annexe has been adapted to use as office space or a studio, extra space for expanding families, or as rented accommodation.


  • A granny annexe can be completely bespoke, unlike a garage conversion or a similar extension, so you have more freedom of design
  • Allows your elderly relatives to continue to live independently whilst also being in a safe, supervised environment
  • Visibly more attractive
  • Robust and well insulated
  • Building a granny annexe is cheaper than a residential home

Granny annexe or extension?

The main benefit of building a granny annexe over an extension, of course comes down to the privacy that having a separate living area creates. The user of the annexe – for whatever purpose – has the ability to retreat to their own space. However, it can be more difficult to gain planning permission for a granny annexe than a traditional extension.

Another consideration is the impact your extension will have on your house value. A typical extension can be considerably cheaper to build, but there is no guarantee that the money you’ve invested will be directly added on to the value of your home as the extra bedroom you’ve added could actually be decreasing the space and comfort levels of your home and property. A separate granny annexe, provided its size is proportionate to your land space, is a fully functional separate home that adds square footage to your property, this means it’s value is much more likely to be proportionate to your spending.