Enclosure of pipes and surfaces must comply with knee and toe space clearance. Recommendation: Where multiple lavatories are provided, insulate pipes at each lavatory since it may not be apparent which fixture is compliant. Lavatory Clearances.
The minimum knee clearance must be free of equipment or obstructions for a minimum of 8 inches (205 mm) extending from the front edge of the lavatory back toward the wall. Figure 31. Lavatory Clearances.
Sinks — ADA Accessibility Articles — reThink Access - Registered ...
The minimum knee clearance must be free of equipment or obstructions for a minimum of 8 inches (205 mm) extending from the front edge of the lavatory back toward the wall. This knee clearance must be 29 inches (735 mm) high at the front of the lavatory and no less than 27 inches (685 mm) high at a point 8 inches (205 mm) back. In addition, a minimum 9 inches.
You would need to provide 22" depth of knee/toe clearance below so that would be 13" deep at 27" AFF + 3" taper + 6" for toe clearance at a minimum. This would be true in California as well as under ADA, but in California you could not use this extra clear depth for reach to the lavatory controls, just the tub. Lavatory ADA knee Clearances For a lavatory, the least form of knee clearance is to reduce the pieces of equipment or remove obstructions for a minimum of 8 inches (205 mm) extending from the front side of the lavatory back toward the wall.
Chapter 6: Lavatories and Sinks
The lavatory requires a 30" (760 mm) x 48" (1220 mm) clear floor space positioned for a forward approach with knee and toe clearance. Refer to Figure G and Figure H. (306 Knee and Toe Clearance, 606.2 Clear Floor Space).
This general clearance at the ADA sink, combined with knee and toe clearance make up the clearance under ADA compliant sinks and lavatories. If you are interested bringing your bathroom up to ADA compliance. talk to a CASp or ADA inspector today.
Lavatories and Mirrors - ADA Compliance - ADA Compliance
This article discusses ADA requirements for turning space, clear floor space, toe and knee clearance, and door swing. A lavatory in a toilet room or bathing facility for a single occupant accessed only through a private office and not for common use or public use shall not be required to provide knee and toe clearance complying with 306.