Mechanical Planning

Today’s modern bathrooms are becoming multifunctional spaces that include an increasingly complex array of electrically powered devices. These electrical and mechanical components include the wiring for various electrical devices: entertainment equipment; heating, air conditioning, and ventilating equipment; and lighting. Consider the location and electrical needs of these items early in the project in order to assure the basic infrastructure is in place before the installation of finishes, cabinetry, and fixtures.

Learning Objective 1: Explain the mechanical systems that should be considered in bath planning.

Learning Objective 2: Describe important considerations for planning ventilation and lighting systems for a bathroom.


Whether building or remodeling, a careful evaluation of the space and planned components is extremely important. Use the Needs Assessment Forms provided in chapter 5, "Assessing Needs," to determine the planned electrical needs of the client. Then consult current codes to see what measures must be implemented in order to meet code approval. You might also suggest additional ideas for improving the system that the client may not have considered, especially those related to future needs or features they may not be able to afford at the current time.


Подпись: I IПодпись: FIGURE 7.1 GFCIS are required in bathrooms by most local codes. NKBA The National Electric Code (NEC) and the Canadian Electric Code (CEC), which are almost identical, assure a safe electrical system which is a major consideration in the bathroom where water and electricity are in close proximity. To improve safety, these codes now require ground fault circuit interrupters (GFCI) (see Figure 7.1) in all bathroom receptacles. These devices reduce the hazards of electrical shock by cutting the electrical flow quickly when they detect that the flow going out to an appliance is different than the flow that returns. GFCI receptacles fit in the same space as the standard receptacles, but need to be appropriately wired.

Most local codes also require that at least one GFCI receptacle be installed within 36 inches (914 mm) of the outside edge of the lavatory (see Planning Guideline 24). These outlets shall be located on a wall or partition that is adjacent to the lavatory basin location, located on the coun­tertop (but not in a face-up position on the countertop), or installed on the side or face of the basin cabinet not more than 12 inches (305 mm) below the countertop.

Furthermore, no receptacles can be placed within the tub or shower space. No switches can be located within wet locations, or within reach of a person standing in the tub or shower, unless the switches are part of a listed tub or shower assembly (see Planning Guideline 24).


One component of older homes that is typically outdated is the wiring. Not only may the older wiring be in poor condition, it may also be made of unsafe materials like aluminum. In either case it should be replaced. Signs of inadequate or outdated wiring include:

• The home is over 30 years old and installed without a grounding system.

• A fuse box is present instead of a circuit breaker box.

• The wiring system has only two wires, and therefore is not grounded.

• Aluminum wire is present.

• No GFCIs are present.

• Fuses blow or circuit breakers trip often.

• Too few switches, receptacles, and lights are present.

• Extension cords are frequently used.

• The electrical supply at the entrance box or main entrance is 100 amps or less.

Aluminum wire, which has been found to develop fire hazards, was frequently used for new con­struction and remodeling from 1965 to 1973. Copper wire is now the wire of choice, so if alumi­num wire is present, the entire home must be rewired as part of the remodeling project. Updating the wiring will ensure that the electrical system is safe and meets current electrical codes.

Adequate wiring for today’s high-tech homes is as essential in the bathroom as in other rooms. Consumers are bringing more electrical devices into the bathroom, so plan ahead to ensure ade­quate wiring is available now and for future needs. Check to see if the room has an appropriate number of circuits. If not, can new circuits be added? Heaters for steam showers, saunas, and tubs will demand a large amount of electricity and may need 240-volt circuits, not commonly specified in older bathrooms. Be sure these new circuits are in place before the finishing work is completed.