Ran into a 19" wide Jack-n-Jill bathroom entry door way today on a new structure in Newport Beach. The listing agent and one of the buyers literally couldn’t go through the opening. The other entry door was a standard 30" with 29" net width between the jambs. Anyone have a code reference regarding minimum size doors for residential structures?
Thanks in advance…
Unfortunately, requirements for doors does not include closet or water-closet doors.
Doors are covered in the California Building Code, Sections 1003.3.1 thru 1005.3.3.3. If the door is part of an exit or exit “passageway,” it falls under these sections, otherwise, there are no clear requirements.
I can send you the chapters if you’d like. . .
Jeff, that is an interesting topic that I would like to persue.
Exit doors are usually 36" front and 32" at the rear of the dwelling, but at least one 36" door required.
Access to bedroom units, a standard size door would be 30" for bedrooms and bathrooms, but sometimes bath’s are 2’ 4".
Closets, usually from 18" to 36".
These are standard sizes and most likely be found somewhere. ?
IBC ?
There has to be, how else have these opening sizes been standard for so long.?
Good one Jeff.
Help. Where did it come from.?
Marcel 
To the best of my knowledge IRC is also moot on this issue (can’t check tonight) I believe IBC has a 28? inch minimum.
Gerry
I too, could only find verbiage on exit doors and or ADA minimum requirements. I’ve run into some very small closet doors over the years, but that was a first for a bathroom entry on a 2 million dollar home.
On another note;
It also had a lower level subterranean laundry room with wash basin and gas fired dryer equipment. No exhaust fan, window or louvered door present for ventilation. I couldn’t find anything in the UBC directly addressing laundry room minimum ventilation requirements as well. I don’t have a copy of the mechanical code. Do you have any thoughts on inadequate ventilation requirments relating to laundry rooms?
Thanks to all in advance…
Closet doors are generally sized in accordance with their use. I’ve seen them as small as 18"x18" (an access hatch basically) up to garage vehicle-door size. I don’t think there are any standards set other than minimums for when they give access to appliances or equipment.
In CA, bathroom (water-closet) doors have minimums only in commercial, multi-family and mixed-use occupancies (occupancy loads of 10 or more), or when installed in compliance with ADA requirements.
Will,
From the International Fuel Gas Code, 2000 (Old, someone may have newer)
“613.1 Installation. Clothes dryers shall be exhausted in accordance with the manufacturer’s instructions. Dryer exhaust systems shall be independent of all other systems and shall convey the moisture and any products of combustion to the outside of the building.”
“613.5 Makeup air. Installations exhausting more than 200 cfm (0.09m3/s) shall be provided with makeup air. Where a closet is designed for the installation of a clothes dryer, an opening having an area of not less than 100 square inches (645mm2) for makeup air shall be provided in the closet enclosure, or makeup air shall be provided by other approved means.”
If a gas dryer is present it should be treated as other gas appliances (furn. & WH). If in a common utility area it should be added to the BTU ratings to calculate the combustion air requirements. Total BTU’s x 50cf / 1000 BTU = volume needed to draw combustion air from (through appropriate grille work as needed). As indicated above, additional makeup air may be needed to compensate for models exhaust discharge rate. (check dryer data plate).
I often incorporate the follwing definitions from the “People’s Energy, Gas Appliance class” (Plug 
) to help explain to clients the danger of improperly enclosing gas appliances to get them out of sight during remodeling or, replacing the louvered door with a solid door to help deaden the noise from the furnace, both potentially deadly DIY projects that I have seen.
"Combustion Air: Adequate combustion air must be supplied for safe gas-appliance operation. Gas appliances operating with insufficient air for combustion and dilution may produce carbon monoxide (CO). CO is a colorless, odorless gas that is poisonous. When CO levels build up indoors, it can be dangerous and potentially deadly. All gas appliances require air for combustion and dilution. This air can be taken from inside or outside the building if specific standards are met."
"Confined Spaces: A confined space is a space in which the volume is less than 50 cubic feet per 1000 Btu per hour of total input for all appliances in that space. Most utility rooms or closets are confined spaces and require special openings to draw combustion air from other spaces. Confined spaces shall have two permanent openings. One opening located within 12 inches of the ceiling, while the second opening is located within 12 inches of the floor. Each opening shall have a minimum free area of one square inch per 1000 BTU per hour of the total input for all gas appliances in the confined space, but not less than 100 square inches of free area."
Not sure if I answered your question on the dryer but maybe these comments will be helpfull to some!! Have a Great Day!!
Thanks Everyone;
I found this on another message board looks like a UBC Code Section:
Sec. 1203.3. Ventilation. Habitable rooms within a dwelling unit shall be provided with natural ventilation by means of openable exterior openings with an area of not less than one twentieth of the floor area of such rooms with a minimum of 5 square feet (0.46 square meters).
In lieu of required exterior openings for natural ventilation, a mechanical ventilating system may be provided. Such system shall be capable of providing two air changes per hour in habitable rooms with a minimum of 15 cubic feet per minute (7 liters per second) of outside air per occupant during such time as the building is occupied.
Bathrooms, water closet compartments, laundry rooms and similar rooms shall be provided with natural ventilation by means of openable exterior openings with an area not less than one twentieth of the floor area of such rooms with a minimum of 1 1/2 square feet (0.14 square meters).
In lieu of required exterior openings for natural ventilation in bathrooms containing a bathtub or shower or combination thereof, laundry rooms, and similar rooms, a mechanical ventilation system connected directly to the outside capable of providing five air changes per hour shall be provided. Such systems shall be directly connected to the outside, and the point of discharge shall be at least 3 feet (914 mm) from any opening which allows air entry into occupied portions of the building. Bathrooms which contain only a water closet or lavatory or combination thereof, and similar rooms may be ventilated with an approved mechanical recirculating fan or similar device designed to remove odors from the air.
Will,
What’s UBC’s definition of “habitable space”? As recent as the 2000 IRC it states “A space in a building for living, sleeping, eating or cooking. Bathrooms, toilet rooms, closets, halls, storage or utility spaces and similar areas are not considered habitable spaces.” From this definition, I spend alot of time not “inhabiting” my home!! I also need to update some of my code books. Not trying to be argumentative, just trying to explain why we don’t see more mechanical fresh air ventilation and air exchangers. Tighter construction has forced contractors to recognize the importance of introducing fresh / makeup air into structures. These design practices have long been recognized by professional HVAC designers as a critical part of balancing a system. JM2cents Have a Great Day!!
The CBC (UBC) definition is the same;
HABITABLE SPACE (ROOM) is space in a structure for living, sleeping, eating or cooking. Bathrooms, toilet compartments, closets, halls, storage or utility space, and similar areas, are not considered habitable space.
That’s why “non”-habitable spaces are addressed separately;
Bathrooms, water closet compartments, laundry rooms and similar rooms shall be provided with natural ventilation by means of openable exterior openings with an area not less than one twentieth of the floor area of such rooms with a minimum of 1 1/2 square feet (0.14 square meters).
It sounds like the second bathroom door might have been an afterthought, and 19 inches was all that was possible for some reason. Bathroom doors can be and often are 24 inches in width. To the best of my knowledge there is no code on door widths other than for main entrance doors. Some stuff is still left to the architect’s judgement. Remember, the code is not a building construction textbook; it is merely a minimum standard. Ideally, there should be someone using their brains and experience in designing a building.
I usually suggest that they install a hanging barn type or pocket door to widen things up a bit. We got some big people here in western PA