Historically, an annexe was an extension to the main house, often over the garage, where older relatives could live outside the family unit but remain within close proximity. The role of the annexe has changed in recent years, with buyers frequently requesting them, and other ancillary accommodation, for less traditional purposes, including:

Airbnb and short-term rentals

If you live in an area popular with tourists – for example, near a festival or race course or by the coast – short-term rentals can be a real moneymaker. The rise in popularity of Airbnb as a cheaper and more homely alternative to a hotel means if you have extra space you can create an income with relatively little effort.

Boomerang kids

With first-time buyers finding it trickier to get on the market due to the difficulties with raising a deposit, we have seen a rise in adult children returning home while they save. According to the Office for National Statistics, the number of 20-34-year-olds living with their parents has increased by 25 per cent over the last decade. Having an annexe means they can maintain their own space and independence – and so can their parents.

Business premises

Annexes are ideal for offices as they allow for the separation of work and home life, but these days they are being used more frequently for other types of business premises. This could be an artist’s studio, kitchen, bakery or even a beauty suite.

Leisure facilities

Once the preserve of the rich and famous, gyms and spas are increasingly finding their way into ordinary homes and if you don't have the space or resources for a whole leisure complex, an annexe is ideal as it keeps the noise made by equipment, music, and so on, away from the main living space.

Multi-generational living

An annexe is a practical way to host relatives of all ages, allowing everyone to maintain their privacy. And there is still space for granny: the traditional use will probably never completely disappear.