1991 ADA Standards for Accessible Design

4.24.5 Clear Floor Space.

A clear floor space at least 30 in by 48 in (760 mm by 1220 mm) complying with 4.2.4 shall be provided in front of a sink to allow forward approach. The clear floor space shall be on an accessible route and shall extend a maximum of 19 in (485 mm) underneath the sink (see Fig. 32).

Fig. 32 Clear Floor Space at Lavatories