Determining the Required Number of Women's Bathroom Stalls for Matched Throughput with a 4 Urinal, 3 Stall Men’s Bathroom

To determine how many stalls in a women's bathroom are required to match the throughput of a men's bathroom with 4 urinals and 3 stalls, we need to consider the average usage rates for each type of fixture. This article explores the estimation of throughput based on usage times and then presents the required number of stalls for the women's restroom to achieve parity.

Assumptions and Estimation of Throughput

Urinals in men's bathrooms typically have a much higher throughput than stalls due to their simultaneous usage and shorter average usage times. Conversely, women's stalls generally have longer average usage times compared to urinals.

Urinals

Following the assumption that each urinal can serve 1 person every 2 minutes, the throughput for one urinal is:

30 people per hour per urinal

For 4 urinals, the total throughput is:

4 urinals × 30 people/hour 120 people/hour

Stalls

Assuming each stall can serve 1 person every 5 minutes, the throughput for one stall is:

12 people per hour per stall

For 3 stalls, the total throughput is:

3 stalls × 12 people/hour 36 people/hour

Total Throughput for the Men's Bathroom

The total throughput for the men's bathroom is the sum of the throughput provided by the urinals and the stalls:

120 people/hour (urinals) 36 people/hour (stalls) 156 people/hour

Required Stalls in the Women’s Bathroom

To match this total throughput of 156 people per hour using only stalls in the women's bathroom, we need to determine the number of stalls required.

Let x be the number of stalls needed. Each stall can serve 12 people per hour, so the equation becomes:

12x 156

Solving for x:

x 156 / 12 13 stalls

Discussion and Architectural Considerations

It is important to note that the above calculation is a theoretical one, based on specific assumptions about usage times. In practice, municipal codes and guidelines may require a different fixture ratio.

Architectural considerations play a significant role in bathroom design. If the men's restroom has 4 urinals and 3 stalls, a practical solution might be to see 6-7 toilets in the women's restroom. This brings the total number to about 7 fixtures, aligning with a 2:1 ratio.

From experience in the architecture/design industry, a common approach is to design women's restrooms with 3 times the number of stalls as in the men's bathroom. While this is not based on empirical data, it has been observed by many commercial and entertainment facility clients to provide a sufficient number of stalls.

In conclusion, to match the throughput of a men's bathroom with 4 urinals and 3 stalls, a women's bathroom would require 13 stalls, based on the given assumptions. However, this number may vary depending on local regulations and practical considerations.