Bathroom Codes and Design Best Practices

A modern-style bathroom

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Building code and good design practices are critical in the bathroom. The bathroom is a dense conglomeration of water supply and drain pipes, electricity, and slippery surfaces—all crammed within a tiny space often no more than 150 square feet in size. Next to the kitchen, it is important to pay attention to spacing and code issues in the bathroom.

Bathroom code and best design practices are not onerous restrictions designed to squeeze your wallet dry and hamper your creativity. Some parts of the bathroom building code and practices may seem trivial, but in many ways, it can be a useful guide as to what goes where and how to space the elements during your bathroom remodel.

Sink Spacing and Design

  • Sinks should be spaced at least 4 inches from sidewalls. Why? One reason is that sinks produce water, and water should be kept away from moisture-sensitive drywall.
  • Sinks should also have a minimum of 21 inches of clearance in front.
  • If you want to place two sinks side by side, make certain that they are at least 4 inches apart from one another.
  • Bathroom code typically mandates that sinks should be at least 4 inches away from bathtubs.

Toilet Spacing and Design

  • Bathroom building code typically says that toilets need at least 21 inches of clearance in front of the toilet. While it is not required, opting for 30 inches of room provides a more comfortable space.
  • Side-to-side clearance: a minimum of 15 inches from the center-line of the toilet to the nearest obstruction. However, 18 inches provides better clearance in most cases.
  • Many communities require water-saving devices on the toilet. New toilets often have these devices pre-installed.

Shower and Bathtub Code and Spacing Practices

  • Shower maximum sizes are not mandated, but minimum sizes are regulated. Shower floor minimum size is usually mandated to be at least 30 inches square; that is, 30 inches by 30 inches.
  • Because shower doors are usually glass and can break and because of other access issues, bathroom code states that shower doors need to have at least 24 inches of opening clearance. This is also a safety issue because users who are forced to slip around narrow door openings are more prone to slipping on the floor.
  • Both showers and bathtubs must have anti-scald devices. Older shower and bath fixtures may not have this feature. All current fixtures will have this.
  • Some communities require water-saving showerheads that limit flow. Inexpensive inserts can be installed between the showerhead and the water pipe to limit the flow of water.

Ventilation and Electrical Code and Design

Bathroom code as it relates to electricity is very important due to the possibility of shocks and fire.

  • All lights over bathtubs and showers are required to be vapor- and waterproof. These are identified by a clear or opaque cover over the bottom of the light: the bulb will not be exposed.
  • All outlets must be GFCI (ground fault current interrupter) outlets.
  • Bathroom code doesn't want you standing in tubs or showers while turning switches on or off, so switches must be 60 inches minimum from these places.
  • Bathrooms do not need to have fans, but they are required to have ventilation. This ventilation can be either in the form of a window at least three square feet in area or a bathroom fan capable of pulling out at least 50 cubic feet of air per minute.

About Bathroom Code and Design Practices

Though based on the framework of model codes, the bathroom code is not the same everywhere. Codes in Maine may not necessarily be the same as codes in Florida. Not only that, but municipalities can add their twists to the code to adapt to local needs.

Bathroom codes in this guide can point you in a general direction. Check with your permitting department to make sure that this code information is applicable to your home and situation. This is not an exhaustive guide; these are only the most popular elements that most homeowners tend to be interested in.

Good bathroom design practices are not building code. Rather, these are helpful guidelines issued by the National Kitchen and Bath Association, a "non-profit trade group that promotes professionalism in the kitchen and bath industry," according to its mission statement. The NKBA has been a leading voice in the kitchen and bath design industry since 1963.