Bathroom Remodel Layout | Design Standards & Principles

bathroom remodel layout

In tackling a bathroom remodel layout, we figure out what is possible and then apply recognized design standards and principles. 

Here’s what we’ll cover.

1: Learn recommended bathroom remodel layout standards
2: Discover what is possible and what is affordable
3: Find the bathroom layout for your situation
4: Incorporate bathroom components in space planning
5: Apply 25 design hints from recognized design principles
6: Get a project planning binder and use it 

Recommended Bathroom Design Standards

Unlike a kitchen, which uses proven space planning approaches such as the work station and work triangle principles and the Illinois Rules, there are no such established dimensional rules for laying out a bathroom. 

However, there are certain minimum standards that are set by code. And there are also the better and recommended standards that we follow. 

State and local codes provide minimum requirements and other bodies have their own recommendations. For example, the International Residential Code (IRC) states that the center line of a toilet should be at least 15 inches from any other bath fixture, wall or other obstacles.

However, minimum standards are not the best standards. By contrast, the National Kitchen and Bath Association (NKBA) says the toilet should be at least 18 inches away from obstacles for better comfort.

As another example, when it comes to clear floor space, the IRC asks for at least 21 inches in front of a lavatory (washbasin), toilet, bidet and tub, and at least 24 inches of clear floor space in front of a shower. By contrast, NKBA guidelines call for at least 30 inches from the front edge of all fixtures to any opposite bath fixture, wall or obstacle.

Further below we address all the principal bathroom components and how they should fit into their surroundings. This is information based on long experience as a remodeling contractor collaborating with NKBA certified kitchen and bathroom designers.

Standards Meet Reality

However, the reality of a bathroom remodel may make these standards academic. The desire for a new and improved bathroom layout runs up against the constraints of what is already there with respect to the structure and the plumbing and electrical systems that are hidden in the walls and floor. These constraints may make changing the bathroom layout either very difficult or very expensive.

The existing plumbing system includes various pipes to bring fresh water into the room and routed to sink, tub and toilet fixtures; pipes to bring hot water from your hot-water heater to tub, sink and shower fixtures; pipes to carry away wastewater; pipes to carry away waste; and vent stacks and P traps to equalize pressure and to keep sewer gasses out of the living space.

The existing electrical wiring system brings power to lights, outlets, and exhaust fans. While rerouting electrical wiring is normally less expensive than making changes to plumbing, it is nonetheless a consideration.

The structure itself may or may not be conducive to change to accommodate a new bathroom layout. For example, it may be possible to annex space from a closet or another room to provide more area. Or it may be possible to increase or decrease the ceiling height. But these too come with a cost.

So the first bathroom remodel considerations are practicality and cost.

Bathroom Layouts

Almost all bathrooms use a layout that follows the plumbing. The plumbing may be in one, two or three walls, known as “plumbing walls.”

  • One-wall layout: where the toilet, sink, and combination shower/tub are aligned along one wall. This makes for a relatively long, narrow bathroom.
  • Two-wall layout: where the toilet and sink are on one wall and the shower and tub (separate or combo) are on the other. The two-wall layout provides a good sense of enclosure
  • Three-wall layout: where the toilet is on one wall, the sink on the second, and the shower and tub on the third. This is a space-saving layout typical of a master bathroom and may accommodate additional fixtures such as a bidet and a second sink, and a separate tub and shower. A bathroom with 3 plumbing walls lends itself best to a remodeling exercise.

Bathroom Remodel Planning

Bathroom remodel planning starts out with establishing its desired function by asking who will be using the bathroom and how.

One of the key questions, where Aging-in-Place is a consideration, is whether one should introduce elements of Universal Design. These emphasize roomier floor plans with wider doorways, taller toilets and curbless showers.

Once the function of the bathroom is settled, its elements will be formed in accordance with established design principles. 

Bathroom Space Utilization

Bathroom space planning mainly involves accommodating the various bathroom fixtures that are included to serve the comfort of the bathroom users. This includes allowing for the maneuvering room required to use them comfortably. Here are the basics for the purpose of developing a floor plan.

Bath Tubs

Clearances: Minimum 30-inch clear space be planned along the side of the tub. More space is preferred, especially if a caregiver and mobility/transfer aid or a wheelchair are involved. Allow a 42-inch to 48-inch dressing circle for someone to dry off and dress. Allow proper clearances for a free-standing tub.

Faucet controls: Accessible to a person before entering the tub. In a tub/shower combination, place the controls 33 inches above the finished floor. Off-setting the controls towards the room improves accessibility. Controls should be easy to grip and operate.  A central control is easier to use separate hot and cold faucets.

Showers

Clearance: Minimum 30 inches of clearance is recommended in front of the shower. A 42 ito 48 inch dressing circle for drying and dressing. 

If a wheelchair or mobility aid is involved, you need a minimum 36 to 48-inch clearance space.

A roll-in shower for someone in a bathing wheelchair should be a minimum 36 inches x 60 inches. To contain water within the shower, it should be minimum 36-inches x  42 inches.

Shower seat: Always include a shower seat. This is in line with the aging in place and Universal Design principles we espouse and recommend. The seat should be 17 inches to 19 inches high and minimum 15 inches deep. It should not obstruct the minimum recommended shower floor of 36 inches x 36 inches.

Shower controls:  A fixed showerhead should be 72 inches from the shower floor, or at another height if the individual user has a preference. However, for greater flexibility, we prefer a shower head on an adjustable bar plus a secondary hand spray. The lowest position for an adjustable height shower or hand spray 15 inches from the shower floor.

Toilets

Toilet placement: Minimum 18 inches from the nearest wall or obstacle (such as toilet paper holder). If you are putting the toilet in a separate compartment, the space should be minimum 36 inches x 66 inches.

Toilet clearance: Aim for a minimum of 30 inches in front of the toilet (even though codes allow for only 21 inches).

Wash Basins

Clearance: A person needs about 18 inches width of floor space for someone to stand for hand washing and about 20 inches depth to bend for face washing. However, 30 inches clearance in front of the washbasin is recommended.

For side by side washbasins and where two people are involved, there should be a minimum 48 inches in width of floor space.

Minimum distance from the center of the washbasin to a sidewall is 20 inches.

Height: The traditional washbasin height is 30 to 32 inches. However, the recommended washbasin height range is 32 to 43 inches. The planning standard is to have the washbasin rim 3 inches below the elbow of the user.

Vanities: These are designed mainly to support the function of the washbasins. However, they provide design statements of their own.

Applying Design Principles to a Bathroom

The nature of a bathroom requires special consideration in applying design principles and achieving an aesthetically pleasing result without sacrificing practicality. Here are some tips:

1: If the bathroom is small, select smaller fixtures, so as not to overwhelm the space.

2: Most bathroom surfaces should be smooth and polished for durability and easy cleaning. However, one should consider non-skid flooring, especially in showers, for safety.

3: Bathrooms tend to be small spaces. Light colors will prevent a closed-in feeling.

4: Do not position a basin underneath a window. People expect to see a mirror.

5: Do not position a toilet opposite the doorway.

6: Do not place the shower at the entrance. This hampers access and restricts vision as you enter.

7: Do not build partition walls, as it makes the room seem smaller. Use clear glass panels for showers, as they are see-through and make the room appear bigger.

8: Do not build uncomfortable and impractical steps in front of a tub.

9: Do not sink the tub into the floor because it will be difficult to clean.

10: The human eye views things in perspective and dimension. So put short things in the front, tall things in the rear, broad things on the floor and nothing bulky on the walls. This creates the illusion of space.

11: Squares and rectangles create sharp corners, which people bump into, and dead ends that restrict access.

12: Making use of rounds and curves helps accessibility and flow in the bathroom.

13: The entry door should open against a wall and not visually cut the bathroom in half.

14: The first visual point upon entering the doorway should be the vanity basin or bathtub.

15: The tallest item, the shower, should be in the furthest back corner.

16: The toilet should be placed as best out of sight as possible.

17: Include a bidet or toilet/bidet combo for function and value.

18: The bath is always a focal point and should generally be close to the vanity basin.

19: Lighting brightens up the room and the brighter the room the bigger it appears to be. The lighting plan should layer and blend four different types of light, task, ambient, accent and decorative.

20: Making use of mirrors creates the illusion of space.

21: Making use of large tiles reduces the amount of grout. This gives a smoother and softer effect. Over time grout becomes discolored and this can shrink the room.

22: Lighter colored tiles also make the room look larger.

23: Make provision for safety by including grab bars.

24: Pay attention to adjoining or complementary rooms. For example, you don’t want the master bathroom color clashing with the master bedroom.

25: Consider a floating vanity for design effect

Get Organized Reminder and Planner

We have offered quite a lot of theory here. But don’t forget the practice. A bathroom remodel may not seem like a very big deal. However, it crams a great deal of detail into a small space. And keeping track of detail requires writing things down. It avoids expensive mistakes. 

We highly recommend this Remodeling Planner. Click on the image link and check it out on Amazon:

remodel binder

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