Whether you call it a guest toilet, half bathroom, guest bath, or a restroom, having a small bathroom in a public area of the house is always a good idea. It allows your guests to feel comfortable in your home without having to wander through your private space. But what if your house doesn’t have a toilet?
Can you set up a guest toilet with a toilet next to your kitchen? You can install a toilet next to the kitchen, but there are several factors to consider. Space requirements, building codes, and sanitation requirements all play a role. You are allowed to have a toilet next to your kitchen, but it won’t be easy.
Next, we will look at the necessary requirements you must meet to install a toilet in a kitchen so you can decide if this is something you want to pursue.
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Building Code Requirements
Previously, building codes required that there be two doors between the kitchen and toilet. Many people still believe that it is not allowed to place a toilet next to a kitchen. However, building codes have relaxed over time. The rules allow for the arrangement of a bathroom next to a kitchen if the construction meets the following requirements.
- There must be a door between the bathroom and kitchen. This is self-explanatory. The space where you cook and serve food should have a physical barrier between it and the bathroom.
- The bathroom must have a sink for handwashing. This is as common sense as it is a building code requirement. You need a sink next to the toilet because everyone needs to be able to wash their hands after using the toilet.
- The new installation must meet all other requirements for plumbing installation, including rules for installation clearances, ventilation, drainage, and venting.
While the first two requirements are easy to meet, most people are unfamiliar with the details of the installation guidelines. Let’s dive a little deeper into the installation requirements that apply to a new bathroom.
Clearances
Building codes require a specific clearance for plumbing fixtures in a bathroom. The center of the toilet must be at least 15 inches away from walls or cabinets. You also need 21 inches of clearance in front of the toilet. The distance between the sink and the toilet should be at least 30 inches from center to center. Many experts recommend a few extra inches, but these are the legally required minimums.
If you want your new bathroom to comply with the Americans with Disabilities Act (ADA), you need 56 inches in front of the toilet and a rectangle of 30 inches x 48 inches in front of the sink. ADA compliance is not required for home renovations, but it is something to be aware of. ADA bathrooms require a lot of floor space, which can make using your kitchen more difficult.
If you are considering adding a toilet near your kitchen to create a half bathroom, you need to consider the clearance requirements when planning. It is not just the toilet that you need to take into account. You need space for the sink and space for the door to swing. You also need to ensure that you leave enough space around the new plumbing lines and that the door can open properly.
Venting
Bathrooms need to use two different types of ventilation. The first is fresh, dry air in the bathroom. You can meet this requirement by installing an exhaust fan in the bathroom or by installing a window that can be opened. Some local codes require both; you will need to check with your local government to be sure.
The second form of ventilation is required for the plumbing pipes themselves. Drain lines must have a stack vent. The stack vent allows outside air to enter your drain pipes. Most people are unaware of this requirement, as the vent pipes are hidden in your walls and attics. If you go up to your attic, you will find pipes leading up from each of your plumbing fixtures.
The drain lines that lead away from both the sink and the toilet must have vent openings that allow outside air into the drain pipes. Some building codes allow for each drain to be connected to a single main vent for the house, while others require separate external vents located within five feet of the plumbing fixture. This is another point that you will need to confirm with your local government.
Installation
Complying with building codes is only half the challenge when installing new plumbing fixtures. The other part is adding incoming water lines and outgoing drain lines. The drain lines must be laid out properly. The drain line must have the proper slope, or it will not drain properly. This is not a place to be approximate. The slope must work.
The critical feature to the proper functioning of a toilet drain is the slope of the drain line leading away from it. You need a 1/4-inch slope for every foot of pipe run. If the slope is too steep, the toilet won’t create the right suction when flushed. If the slope is not steep enough, the drain line won’t drain at all.
If you have a slab floor, it is often easiest to achieve this slope by raising the toilet’s base a few inches and then running the drain line through the walls. You can run the line to the next exterior wall and then drop it steeper to connect to the main sewer line in front of your house. Running pipes through walls is significantly easier than running them through slabs.
If you can’t go through the wall, the other option is to run the line through the slab. You can either dig through the slab and create a tunnel from the new drain line to the existing sewer line, or you can break a channel in the slab and embed the pipe in concrete. Neither option is particularly easy.
If your house is on a pier and beam foundation or has a basement, you have a much easier path. You simply run the pipe under the floor in the crawl space or basement. Make sure you have the proper slope, and you’re good to go.
You also need a drain line for the sink to connect to. This can be tied into the toilet line; you don’t need to bore two holes in the wall or the foundation for the sink to drain properly.
Running Water
Of course, all of this drain line needs water. Bringing water into the bathroom is much easier. Since the water is under pressure, the slope of the pipes doesn’t matter. You can tap into the kitchen’s water supply for the incoming water lines. You will need both hot and cold lines for the sink, while the toilet only needs to be connected to the cold line.
The lines can be run through the existing walls to bring the pipes into the new bathroom. PEX piping is an excellent choice for this. It is somewhat flexible, making it easier to work through holes in wall studs than PVC or other rigid pipes. You will need to get the proper fitting to connect the PEX to your existing plumbing, but that is not overly difficult. PEX is very forgiving and easy to work with.
Putting it All Together
Building codes allow you to create a new half bathroom next to a kitchen, but it’s not a small project. Drain lines and concrete foundations are both unforgiving. It’s easy to damage one or both when adding a new bathroom. Unless you are an experienced plumber or have the utmost confidence in your construction skills, this is a job for a professional.