Minnesota Department of Labor and Industry Orange bar
Minnesota Department of Labor and Industry

Requirements for plumbing fixtures - IBC Chapter 29

2003 Minnesota State Building Code
Requirements for Plumbing Fixtures - IBC Chapter 29

Based on the inquiries we receive, plumbing fixture provisions from IBC Chapter 29 seem to be generating a lot of confusion; specifically in regards to the number and type of required plumbing fixtures in a "unisex" restroom.  The intent of this commentary is to provide some direction and clarification on this and other provisions of IBC Chapter 29.

Design provisions for using a unisex restroom.  Generally, we start with the requirement that all buildings or tenant spaces require separate sex facilities.  That simply means we always start with two separate toilet rooms - a "men's" and a "women's" restroom - each having the minimum quantity of fixtures calculated from Table 2902.1.  In this example however, we'll assume we have a minimal occupant load that allows us the potential to install a single "unisex" restroom.  Initially, we need to be open to the idea of looking at the scenario from both the design and plan review standpoints.  From there we try to determine the perspective used to confirm the unisex code requirement.  We begin with making a determination on the occupancy or use of the condition being analyzed.  Is the building/space classified as a Group A-2 restaurant?  Is it a Group B insurance office?  Or is it a Group M retail coffee shop?  Once we determine the actual "use" condition, we compute the occupant load from IBC Table 1003.2.2.2 and then move back to IBC Chapter 29.  Note that these two conditions are essential in making final considerations on the unisex restroom.  Once we have determined the occupancy use and the total occupant load of the space under consideration, we look to determine if an exception of section 2902.2 applies. Under IBC Section 2902.2, with a Minnesota amendment, there are four conditions or exceptions that allow us to consider a unisex restroom.

Exception 1 can be ruled out right away because it only applies to a private restroom installed for an individual user.  An example of that condition might be a restroom within and serving an individual hotel room or dwelling unit.  In this example, the restrooms are considered "private" and exception 1 could be applied.  Under exception 1, the single unisex restroom requires just one water closet and one lav within the room.\

Exception 2 is qualified not only by the number of persons computed in the occupant load, but by "whom" the restroom use is intended for.  This exception can only be applied when we have 15 or fewer persons computed in our occupant load and those persons under consideration are employees only.  An example of this condition might be a small factory or warehouse where the space is occupied by building employees only.  If we are specifically dealing with 15 or fewer employees, a unisex restroom can be installed.  Under this exception, the single unisex restroom requires just one water closet and one lav within the room.

Exception 3 is similar to exception 2, but under this scenario the persons being considered can be both employees and patrons/customers.  The maximum occupant load is still limited to 15 persons, but it is both patrons and employees that we are talking about.  An example of this situation might be a small dental clinic or insurance agency office where we have both employees and customers occupying the space.  Under exception 3, the single unisex restroom requires just one water closet and one lav within the room.

Exception 4, a Minnesota Amendment to the 2000 IBC, is specific to Group B and Group M occupancies only.  It may not be used or applied to any other occupancy group classification.  It further requires that those Group B and M occupancies be limited to 2000 Gross Square Feet in area.  If the spaces under consideration are larger than 2000 GSF, this exception cannot be used.  Note that the provision does not reference a maximum occupant load.  That was intentional.  If the space meets all the prerequisites to use exception 4 - and the designer/owner chooses to use exception 4 - the individual unisex restroom can be installed.  This is a big change from exceptions one, two, and three.  Exception 4, and only exception 4, requires one water closet, one lav and one urinal all in the same unisex restroom.  There are no options to the required fixtures under this provision; three primary fixtures are required in the same unisex restroom.

Many people have contacted the Division regarding exception 4.  What we are finding is that most seem to believe that each of the three fixtures required by exception 4 are also required under exceptions one, two and three.  That is not the case; nor is it the intent.  The history of this issue stems back to the Building Codes and Standards Division IBC Advisory Committee and the many concerns the Division had received regarding the larger floor area separate sex restrooms require in smaller tenant spaces.  Exception 4 was specifically added to allow for a reduced floor area dedicated to restroom facilities to essentially "cut the owner a break" on the added construction cost.  It was also included to address complaints regarding sanitation and use of the restroom by both sexes.  The three fixtures were formulated as a compromise to meet all of the concerns in these small spaces.

Calculating occupant loads for plumbing fixture determination.  IBC Table 1003.2.2.2 should be used to determine the number of occupants within a building.

Restroom facility ratio's in places of public accommodation (MSBC 1303.1200): When considering assembly uses, IBC Table 2902.1 makes our work somewhat easy.  It has separated all assembly type uses in the table under the heading of "assembly."  For all uses in the assembly category, the ratio of 3:2 (female to male) as required by Minnesota Code, is already factored in.  To make the determination, we first compute the total occupant load and then divide the total occupant load by two - applying 50 percent of the load for men and 50 percent for women.  We then work in the required plumbing fixture ratio from the actual assembly use category under consideration.  The end result will give us the minimum number of plumbing fixtures and we will have the required 3:2 ratio automatically figured in.

For the non-assembly use conditions listed in Table 2902.1, the fixture computation is slightly different.  The occupant load for the space is computed and the ratio is worked in as usual, but once you've determined the total number of plumbing fixtures, you divide the resulting number of required plumbing fixtures by two.  You should generally assume a 50/50-fixture count (male and female), but if circumstances dictate that a different ratio is needed, an adjustment can be made if approved by the Building Official.  An example of where this scenario might apply could be an all-male or all-female gym or college situation.  In a case such as this, when you know there is a higher ratio of one sex to another, an adjustment could be considered.

Computing the number of urinals for men's restrooms.  IBC Table 2902.1 states that one should reference the International Plumbing Code (IPC) for determining the number of urinals in men's restroom facilities.  Under the global adoption provisions of the Minnesota State Building Code, we state that wherever there is a reference to the IPC, that means the Minnesota State Plumbing Code.  The current state plumbing code however, does not include provisions for making this determination.  Consequently we cannot "track" applicable code language for determining urinal substitutions.  As a result, the Division has taken the position that one should use the IPC code language until it can be corrected under the next code cycle.  The reference language in the IPC states that "urinals shall not be substituted for more than 67 percent of the required water closets." 

Drinking fountain requirements.  In other than the "residential" type use conditions found in IBC Table 2902.1, you'll find that at least one drinking fountain is required in every use condition.  IBC Table 2902.1 also states (under the table heading for drinking fountains) that one should refer to the International Plumbing Code (IPC) for additional information on drinking fountains.  Again, under the global adoption provisions of the Minnesota State Building Code, we state that wherever a reference to the IPC is found, that means refer to the Minnesota State Plumbing Code.  Again we find that the current state plumbing code does not include design provisions for drinking fountains; so once more we cannot "track" applicable code language for dealing with design alternatives.  If we look at the IPC however, we find that it allows us to rescind the general requirement for drinking fountains in restaurants.  Additionally, we find language that implies that a bottled water cooler is an acceptable substitution seemingly to any use condition.

The Division recognizes that there was a specific intent to allow for deviation in some instances from the drinking fountain design requirements found in IBC Table 2902.1.  Because of this, the Division is recommending that code officials use this reference as an acceptable alternative in use conditions where the installation of a drinking fountain just doesn't seem to make good sense.  Examples of this condition may be a restaurant or small store type use where water is freely available, a small office, factory or storage use where an employee break room exists and a water cooler is provided, or in the instance where a building is to be normally unoccupied.  Another example where this may be acceptable is where required drinking fountains or water coolers have been provided in another adjacent building on the same site, similar to the provisions of IBC section 2902.4.  If conditions seem to be appropriate, we believe this to be an acceptable alternative.  This tracking condition is just another of the issues the Division intends to correct in the next code cycle.

In conclusion, the Division would also like point out that the Minnesota Accessibility Code (MN Rule 1341) contains provisions that further regulate design, installation and use conditions of most restrooms and plumbing fixture conditions referenced in this article.  Factors such as minimum clear floor space at plumbing fixtures, fixture control locations, operation and reach ranges, grab bar provisions, etc., must all be included in both the design and the review of a required accessible restroom and drinking fountain/water cooler.

October 1, 2003
Paul Heimkes
Building Code Representative/Plan Review Section
Minnesota Building Codes and Standards Division

DLI home page | Directions and maps | News and media | Website disclaimer