Knowing where to put the bathroom when building or remodeling is just as important, if not more important, as bathroom space or layout planning. Where one leads, the other follows: bathroom location often dictates the bathroom layout. A wisely placed bathroom means the difference between an efficient, smooth, and economical build or remodel, as opposed to one fraught with annoying cost overruns and delays.
Of the utilities, water supply and drainage are the main concerns when deciding where to put the bathroom, followed closely by electrical and ducting issues.
- Water Supply: Incoming hot and cold water lines are needed for the sink and for the bathtub, shower, or tub/shower combination.
- Drain System: The sink and the bathing facilities both need to drain out to the house's main drainage system.
- Sewer Line: A large three- to four-inch pipe connects to the toilet flange, and this pipe must drain from the home to the sewer main located under the street.
- Electrical: Bathrooms are heavy users of electricity, with the electrical code specifying a minimum number, type, and placement of electrical outlets and lights.
- Ducting: When a bathroom exhaust fan is installed, it must vent to the exterior, either laterally or vertically through the roof. This duct runs through the plenum above the ceiling.
Adequate space must be allocated for the bathroom. A bathroom space that is five feet wide by 12 feet long is generally accepted as the minimum for installing a full bathroom. The five-foot width is wide enough to accommodate an alcove bathtub, and the 12 feet of length is just enough to fit a toilet, bathroom vanity cabinet, and sink.
Additionally, the space should not be unusually shaped due to the uniformity of the bathroom elements. With alcove bathtub bathrooms, the width must be exactly 60 inches, in order to accommodate the 59 1/2-inch bathtub.
Sturdy, Level Floor
Bathrooms are heavy rooms. Not only are the individual elements heavy—toilet, cabinet, sink, tile, flooring, and bathtub and shower—but when filled with water and items, their weights increase exponentially. An empty acrylic bathtub and surround combination can weigh about 200 pounds, while a bathtub full of water may weigh between 500 and 750 pounds. A ceramic or porcelain tile floor, combined with an underlayment, thinset, and grout, also can weigh hundreds of pounds.
A bathroom is not helpful if it is difficult to get to. An en suite bathroom (located within a large, primary bedroom) always is favored by homeowners for maximum convenience. Bathrooms located a short distance down a hallway from the bedrooms also are considered convenient. Try to keep bathrooms on the same level as the bedrooms.
About This Term: Primary Bedroom
Many real estate associations, including the National Association of Home Builders, have classified the term "Master Bedroom" as discriminatory. "Primary Bedroom" is the name now widely used among the real estate community and better reflects the purpose of the room.
Read more about our Diversity and Inclusion Pledge to make The Spruce a site where all feel welcome.
Proximity to Water Heater
When the water heater is located at the opposite end of a house from a bathroom, it can take a long time for the hot water from the heater to reach the hot tap in the bathroom. Fifty feet of standard 1/2-inch pipe contains 0.8 gallons of water. This means that nearly one gallon of cold water must be expelled—that is, wasted—before hot water reaches your bathroom sink, shower, or tub.
Rarely will a bathroom be located in a certain area solely due to its proximity to the water heater, but it is good to be aware of this potential complication. One way to circumvent this problem is to install a tankless, on-demand water heater located in or near the bathroom.
Adjacent to Another Bathroom
The classic placement for two bathrooms in a house is to have one bathroom next to the other, separated by a wall. The shared wall serves as a type of utilities core, with electrical lines, water supply, drainage, and sewer line running through that wall. The two bathrooms often are mirrored to save on money: sinks, toilets, and showers or bathtubs are repeated at the same place on each side of the wall.
Above or Below Another Bathroom
Another good place to put the bathroom is directly under or over another bathroom. As with placing bathrooms next to each other, services are easily shared between the two bathrooms.
Above, Below, or Near a Kitchen or a Laundry Room
A bathroom can be placed over, under, or near a kitchen or a laundry room. This arrangement allows the bathroom to take advantage of the water supply and drainage systems that are already in place, plus there will already be electrical wires that can be tapped into. The bathroom exhaust fan cannot share a duct with the laundry room; its duct must run independently to the exterior.