Kitchen work triangle

Work on optimizing kitchen layouts was begun in the 1920s by Lillian Moller Gilbreth, an industrial psychologist and engineer, in partnership with the Brooklyn Borough Gas Company. Gilbreth's Kitchen Practical was unveiled in 1929 at a Women's Exposition based on Gilbreth's research on motion savings. Gilbreth referred to the L-shaped layout as "circular routing" which later came to be called the kitchen work triangle.[1] A specific model was developed in the 1940s[2] to address the efficiency of the kitchen space between the major work centers: Cooking (range), Preparation (sink/dishwasher) and Food Storage (refrigerator). It was designed to maximize the efficiency of a one-cook kitchen that stemmed from Taylorist principles that had to do with time-motion studies from around the turn of the century. The University of Illinois School of Architecture developed the work triangle to emphasize cost reduction by standardizing construction. This resulted in a variety of configurations.

The kitchen work triangle principle is used by kitchen designers and architects when designing residential kitchens. Recommended dimensions and layouts will vary with different building codes around the world, but some examples are:[3][4]

• No leg of the triangle should be less than 1.2 m (4 ft) or more than 2.7 m (9 ft).
• The sum of all three sides of the triangle should be between 4–8 m (13–26 ft).
• Cabinets or other obstacles should not intersect any leg of the triangle by more than 30 cm (12 in).
• If possible, there should be no major traffic flow through the triangle.
• A full-height obstacle, such as a tall cabinet, should not come between any two points of the triangle.

Besides the work triangle itself, there are several rules of thumb to consider when planning a kitchen:[3][4]

• As measured between countertops and cabinets or appliances, work aisles should be no less than 110 cm (42 in) for one cook, or 120 cm (48 in) for multiple cooks.
• A sink should have a clear counter area of at least 60 cm (24 in) on one side, and at least 45 cm (18 in) on the other side.
• A refrigerator should have a clear counter area of at least 40 cm (15 in) on the handle side; or the same on either side of a side-by-side refrigerator; or the same area on a counter no more than 120 cm (48 in) across from the refrigerator.
• A stove or cooktop should have a clear 40 cm (15 in) area on one side, and at least 30 cm (12 in) on the other side.
• At least 91 cm (36 in) of food preparation area should be located next to the sink.
• In a seating area where no traffic passes behind the diner, allow 80 cm (32 in) from the wall to the edge of the table or counter; if traffic passes behind the diner, allow 110 cm (44 in).

Quite a few things have changed since the 1940s when the concept originated. After the Second World War, typically it was the housewife who cooked, cleaned, ironed, and served the family meals; kitchen sizes were generally smaller than today. The kitchen was considered a working area, and planning considered mostly utilitarian angles.

The original functions described with the kitchen triangle still exist within the modern-day kitchen. However, technologies (like microwaves and other appliances) and the way kitchens fit into the modern (Western) lifestyle have changed. Many kitchens have grown to accommodate more than one cook, so cooking zones were developed that are similar to the layout and zoning of commercial kitchens. With the housing boom and the expanding wealth of the Baby Boomers, the size of kitchens in the United States has expanded.

This allows for commercial style appliances, and zones for various functions that were outside of the traditional triangle, such as prep stations that might include another smaller sink, and bake centers that had areas specifically for rolling out dough and baking that were separate from the main cooking appliances and food prep areas. These additional zones might overlap in terms of sharing components and create secondary triangles.

In the early '90s, the National Kitchen & Bath Association introduced the multiple rectangle concept - the idea being where the microwave or separate ovens were considered a fourth or fifth element, taking into account families who didn't always eat together and the assumption that there might be multiple cooks. It never caught on - partly because of insufficient PR and partly due to too much flexibility in deciding what the four corners of the rectangle actually were.

A later concept is that of kitchen zones. In this layout, the proportions of the triangle are no more an ergonomic requirement. There are usually four zones present: food preparation, baking, cooking, and cleaning.

• "The Work Triangle: Design for Living". Kohler Company. Retrieved 2016-01-26.
• Gilbreth, Jr., Frank B., and Ernestine Gilbreth Carey. (1950) Belles on Their Toes, Chapter 10, "Efficiency Kitchen" - a lighthearted account of Lillian Gilbreth's kitchen design, by two of her twelve children.