Bathroom Space Planning: Guidelines and Recommended Practices

  • 01 of 04

    Bathroom Spacing: Code vs. Guidelines

    Modern Bathroom
    Modern Bathroom. Getty / 3D Image Design

    You might be surprised to learn that building code is relatively silent on matters of spacing toilets, sinks, bathtubs, and showers.  Instead, industry groups such as the National Kitchen and Bath Association (NKBA) issue recommendations that most bathroom and kitchen designers use when laying out the rooms.

    Bare Minimum:  Good Enough?

    However, these are absolute bare minimum spacing guidelines.  If you have any extra room, you should bump up the NKBA number by several inches.

    One clearance issue...MORE that always comes up:  how much space should you leave in front of a toilet?  

    In a powder or guest bathroom, this is rarely a problem because the front-of-the-toilet obstruction is usually a shower or tub--absent in powder rooms.

    NKBA's minimum clearance is 21 inches (see next slide for details), but as this allows less than two feet in front of the toilet, it is critical to increase that measurement whenever possible.

    Center Line and Sizing

    Spacing designations often use a term called "center line."  This means drawing an imaginary line down the center of the fixture, with the line crossing over the drain hole.  Center line is meant to take into account the width of standard-sized items.  If you have items that differ from standard size, adjust accordingly.

    Continue to 2 of 4 below.
  • 02 of 04

    Toilet Space Clearance, Front: 21" Minimum

    beautifully tiled bathroom
    Peter Mukherjee / Getty Images

    Front toilet space clearance not only ensures that the toilet-user has enough room to take care of needs, but that other services (namely shower, sink, tub, and door) remain unobstructed.

    • Minimum: 21" (National Kitchen and Bath Association Guidelines)
    • Recommended: 30" +

    You cannot have too much toilet front space. Consider the NKBA-recommended 21" minimum to be the absolute bare minimum.  .

    Note, too, that with the advent of longer-bowl residential toilets, you will want to make sure...MORE that the toilet flange has extra space.


    This bathroom has 30"+ toilet front clearance space.  This is due to the placement of the toilet between the sink and bathroom, not facing them.

    Continue to 3 of 4 below.
  • 03 of 04

    Toilet Side Clearance: 15" Minimum

    Small Half-Bathroom or Powder Room
    Small Half-Bathroom or Powder Room. Getty / slobo

    When measuring toilet side clearances, always measure from the toilet's (imaginary) center line to the nearest side obstruction.

    If mounted on the wall, the toilet roll holder will need several inches of extra space, as well.

    • Minimum: 15"
    • Recommended: 18" +

    If you have a wider-sized toilet, you will want to add more side space.


    In the bathroom shown here, the distance from the toilet's center line to the wall on the right and the pedestal sink on the left is about 15",...MORE each.  This is a good example of how spacing guidelines only provide for the absolute bare minimum, as this is powder room (or guest bathroom) with very tight confines.  The recommended spacing of 18" would likely be preferred by both the homeowners and by users of the bathroom.

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  • 04 of 04

    Bathroom Sink and Counter Spacing and Placement Guidelines

    Double Basin Cut Out Bathroom Vanity Top
    Double Basin Cut Out Bathroom Vanity Top. via Amazon

    Placement guidelines differ between single and double basin sink configurations.  

    Double Basin Placement From Each Other

    36" away from each other, measuring from center line to center line.

    This is the recommended minimum distance. At a bare minimum, ensure that the basins are at least 4" apart, measuring from the edge of one basin to the adjacent edge of the next basin.

    Sink Distance From Wall

    20" recommended; 15" bare minimum. Measure from center line of sink.

    Counter Placement From...MORE Front Obstruction

    30" recommended; 21" bare minimum. Measure from edge of countertop.


    These spacing guidelines apply only to countertops where you are making the sink cutouts.  If you purchase a bathroom vanity top, you will not have any choice as to sink cutout placement; they come pre-cut.  However, you can expect that they will be correctly placed and spaced.