ADA bathroom requirements affect every small business with a brick-and-mortar retail space. Since passage of the Americans with Disabilities Act (ADA) in 1990, business owners are mandated to modify their physical structures in order to meet the needs of millions of Americans with disabilities. Broadly speaking, the federal legislation applies to a building’s approach and entrance, access to goods and services, and ability of disabled individuals to use water fountains and other public amenities. It also applies — with very specific guidelines — to the accessibility and use of a building’s public restroom.

Of course, bathrooms in every commercial setting should be designed to impress customers, rather than drive them away. But it’s also every business’s responsibility to follow ADA bathroom requirements, or risk facing severe penalties. Consider the following guidelines when designing your bathroom:

Per ADA guidelines, a bathroom or handicapped toilet stall should have ample space so that a single wheelchair is able to freely rotate within it (a minimum of 60 inches in diameter for a complete 180-degree turn). This space must be designed for a forward or parallel approach to the equipment, and can be located beneath current fixtures as long as there is enough space to allow legs to move freely when a person is seated in a wheelchair.

According to Buildings Magazine, an ADA-compliant toilet should have a 60-inch width, at minimum, with enough space to accommodate a wheelchair on the sides of the toilet or directly in front of it. Following installation, the toilet seat is required to be between 17 and 19 inches from the toilet base to the top of the seat.

According to the ADA, you should anchor the horizontal grab-bar handrail and make sure it has a smooth, easy-to-grasp surface. It should be installed on the closest wall or partition.

An ADA-compliant bathroom should contain a sink or countertop no more than 34 inches high, with enough open space beneath for acceptable knee clearance, according to Buildings Magazine. Plumbing located beneath a countertop or sink must be insulated or protected in such a way that it doesn’t interfere with the disabled customer’s movement.

Any mechanism requiring a patron’s use (faucets, knobs, valves, etc.) must be workable with just one hand. Buildings Magazine also recommends that faucets “be lever-operated, push, touch or electronically controlled” and never require having to “tightly grasp, pinch or twist the wrist.”