In addition to proximity to the soil stack, where you choose to install a loo is limited by the requirement that a room containing a WC must not open directly on to a living room or kitchen and, for obvious reasons, there must be a ventilated lobby in between. As a hallway can act as a ventilated lobby (providing the doors to the adjoining rooms are left in place), a toilet can be created in the space below the stairs. But first consider its size: while it may conform to length and width to the minimum already mentioned, is it high enough?
If the door is to open outwards into the hall, will it clash with other doors close by? Good ventilation is also necessary. lf there is no external wall, it is possible to install a ceiling – mounted extractor fan, provided it can extract into a loft space above or ducts can connect it to the outside.
Incorporating an outhouse
An existing outside toilet at the rear can be incorporated into the structure of the house, providing the ventilated lobby requirement can be met. In older houses which have a toilet beyond the kitchen, there is often a redundant coal shed which can act as the lobby.
A utility room
lf a utility room adjoins the kitchen, it is sometimes possible to poach a small space to create a downstairs cloakroom. Depending on its size and the appliances housed within it, some judicious doubling up could free the required extra space. Try stacking the tumble dryer on top of the washing machine or investing in a combined washer/dryer; sacrificing a chest freezer for a more space-saving upright one; or replacing a large sink with a smaller inset model, smart enough to act as a handbasin, and so on. Position the \/\/C at the far end of the room, separated by a partition wall and door, and the reduced-size utility room now acts as the required lobby.