Space

Think carefully about the space you already have, before cutting into it. A large area with good light and sight lines is a very precious thing, but not when it’s at the expense of utility. An architect will be able to attend to every potential pitfall, so it’s good to get one on board early. ‘Available light, access and the shape of the existing room will all affect what can and can’t be done,’ says a spokesperson from architects Robert Dye.

If you have high ceilings, the practice suggests a minimum ceiling height of 3.1m is necessary to install a mezzanine; this will allow you to sit up in bed, but not stand. ‘The overall proportions and height needed are governed by the new addition’s function,’ adds the Robert Dye spokesperson. Although sleeping areas don’t have to be full-height, the incorporation of a kitchenette or bathroom will require a total room height of 4m or more.

Also, think about how you will access your new area. Even if you have sufficient height for another level, the space required for stairs or a ladder may compromise the larger area too much, or cut in front of an existing window or door. Similar considerations apply if you’re thinking of a room within a room. ‘If it takes up too large a proportion of the existing room, it will begin to dominate,’ says Block Architecture’s Zoe Smith, who advises that any bedroom ‘pod’ be scaled to the existing room, so that it takes up no more than 25 per cent of the room in which it’s placed.