The amount of floor area suitable for each room will depend heavily on your individual lifestyle and your reasons for creating a bespoke home. Architect Julian Owen takes a look at what different households are likely to need

Choosing the size and shape of individual rooms is an early challenge when designing a new dwelling. A helpful starting point is to measure up the house you currently live in and use these dimensions to decide which rooms need to be larger or where you can afford to lose space if downsizing.

The following pages will offer guidelines for minimum room sizes based on common living requirements for different households. However, the whole point of selfbuilding is to satisfy individual needs rather than accept a standard floor plan that you could find in any estate of newly built homes, so these won’t apply to everyone.

In Britain, house floor areas peaked in size in the 1970s but have since shrunk by 20% and are now very close to those seen in the 1930s, before there was a substantial programme to build council houses with decent floor areas. Some of you may find the minimum sizes stated restrictive, but these have come from reliable data issued by the government; in fact, many families live in smaller.

Bear in mind that the floor area doesn’t necessarily indicate the capacity of a room if you’re not considering its shape. It’s much harder to plan a successful furniture layout for a small L-shaped room than for the same area with four walls, for instance. The design of the circulation routes in the house is also important; a poor layout will have lots of corridors and invisible pathways through open-plan spaces that have to be kept clear and so cannot be used. Prevent this kind of problem by planning what furniture is likely to go in each space and working out a scaled plan including individual items’ positioning.