In reality, the International Residential Code specifies a 30' by 30' footprint for a walk-in shower. The National Kitchen and Bath Association suggests a greater size, namely 36' by 36'. The most popular size for a rectangular walk-in shower is 36' by 48'. This allows you to bathe at least three people at once.
The overall volume of a walk-in shower is fairly large, so it's important to choose your materials carefully to avoid excessive weight or cost. The typical metal-frame walk-in shower weighs about 200 pounds, while fiberglass versions can weigh up to 800 pounds. A concrete floor with a waterproof membrane under it is required for any type of shower. The surface should be smooth and flat to reduce slipping when getting in and out of the tub.
A door with glass or clear plastic panels is required to provide access to the tub. There should be room for someone to stand inside the shower without touching the walls. If there are no windows, consider installing a mirror instead. Mirrors can also be used to create an illusion of larger spaces by making the user feel like they're walking into a giant wall of water.
There should be enough space behind the shower curtain to stand upright with our arms crossed. Most manufacturers recommend at least 32 inches, but we often see them made with 42 inches to allow for some flexibility in styling.
If you intend to use certain "universal design" ideas in your shower installation, the stall should be at least 36-by-36 inches, preferably 42-by-60 inches. This no-threshold walk-in shower was created for a person with limited mobility. The door can be opened from inside the tub for safety reasons or to get out easily.
For people who are not disabled, but still want a walk-in shower, there are mini-showers that can be installed outside their home. These showers are usually about 30 inches wide and 60 inches long. They need to be located away from houses so they do not attract vandalism. Mini-showers can also be purchased as part of a set with handrails and other accessories for use by multiple people at one time.
Doorless showers are the most common type of shower available in retail stores and home centers. These showers do not have any doors or walls between them and the exterior of the building. So if someone were to open the shower curtain or turn on the water while you're inside another person could see you! Doorknobs and handles are optional on doorless showers because anyone able to reach them could open them. But even if they cannot, they can still use the shower by standing behind the wall where the handle or knob would be if it were present.
A shower should, in general, be at least 36 inches square. If your bathroom is really small, 30 inches square is the absolute minimum size necessary for a shower. Step inside a couple showers at a plumbing showroom or home improvement store to establish the minimum shower size you'll require. Most people prefer showers that are 42 inches wide.
If your bathroom is larger than 30 inches square, there's no need for concern. However, if you ask most homeowners how they like their showers, they will tell you that they want it to be at least 42 inches long. Longer showers feel more spacious and allow for more room to bathe comfortably. They also allow you to use more efficient shower heads.
The overall length of your shower should be based on how you take your baths. If you usually just wash yourself quickly, a 45-minute bath is enough length for you. But if you like to soak for ages, then a 60-minute bath is required. No one else will judge you if you choose different lengths of showers periodically.
The maximum height of a shower is limited only by doorways and other structures within the bathroom. Generally, people don't go over 4 feet tall, so any higher than that and you're not going to be able to get all the way through the shower without assistance.