A toilet must be placed at a specific distance from the walls surrounding it to create both a comfortable and a legally compliant setting. These distances should be planned for before you install the fixture. When you're planning and designing the bathroom, you can adjust the specific distance from the toilet to the walls as a function of your personal likes and needs.
Rear wall distance
The standard distance from the wall behind the toilet's location to the centre of the drain underneath the toilet is 30 cm (12 inches). This distance is called the "rough in," and most toilets are designed to fit this measurement. Some toilets can be obtained with a different rough-in measurement, which may measure either 25 cm or 35 cm (10 or 14 inches). Matching this measurement, whether 25, 30 or 35 cm (10, 12, or 14 inches), with the toilet's rough in allows the toilet tank to fit properly against the wall.
Front and side wall distance
Toilets should be placed with 37/5 cm (15 inches) of distance between the side walls and the centre line of the toilet. Popular building advice also recommends 52.5 cm (21 inches) of clear space from the front edge of the toilet to the front wall, allowing leg room for individuals seated on the toilet. Local building departments may enforce different codes in different areas.
Measuring a toilet rough in
To measure and determine your present toilet's rough in, extend a ruler from the wall behind the toilet to one of the bolt caps, which are located in the toilet base. Measure from the finished wall, not from the wall baseboard, to obtain a proper measurement. Do this before you obtain a new toilet, in instances when you are replacing the fixture. Measure from the finished wall to the centre of the drainpipe where the waste exits the toilet if no toilet has yet been installed.
The Building Regulations Approved Document M 2004 (Access to and use of buildings) provides guidelines for buildings and facilities to provide accessibility to the disabled. Those guidelines call for at least 40 cm (16 inches) of space from the toilet centre line to one side wall. The other side of the toilet should have a similar gap to a wall if the toilet has 1.1 m space in front of it. The space in front of the toilet should be at least 80 cm. In cases where less then 1.1 m is available in front of the toilet, one side of the toilet should have a space of 1 m from the wall to the centre of the toilet.