Domestic kitchen planning
Domestic kitchen design per se is a relatively recent discipline. The first ideas to optimize the work in the kitchen go back to Catherine Beecher's A Treatise on Domestic Economy (1843, revised and republished together with her sister Harriet Beecher Stowe as The American Woman's Home in 1869). Beecher's "model kitchen" propagated for the first time a systematic design based on early ergonomics. The design included regular shelves on the walls, ample work space, and dedicated storage areas for various food items. Beecher even separated the functions of preparing food and cooking it altogether by moving the stove into a compartment adjacent to the kitchen.
Christine Frederick published from 1913 a series of articles on "New Household Management" in which she analyzed the kitchen following Taylorist principles, presented detailed time-motion studies, and derived a kitchen design from them. Her ideas were taken up in the 1920s by architects in Germany and Austria, most notably Bruno Taut, Erna Meyer, and Margarete Schütte-Lihotzky. A social housing project in Frankfurt (the Römerstadt of architect Ernst May) realized in 1927/28 was the breakthrough for her Frankfurt kitchen, which embodied this new notion of efficiency in the kitchen.
While this "work kitchen" and variants derived from it were a great success for tenement buildings, home owners had different demands and didn't want to be constrained by a 6.4 m² kitchen. Nevertheless, kitchen design was mostly ad-hoc following the whims of the architect. In the U.S., the "Small Homes Council", since 1993 the "Building Research Council", of the School of Architecture of the University of Illinois at Urbana-Champaign was founded in 1944 with the goal to improve the state of the art in home building, originally with an emphasis on standardization for cost reduction. It was there that the notion of the "kitchen work triangle" was formalized: the three main functions in a kitchen are storage, preparation, and cooking (which Catherine Beecher had already recognized), and the places for these functions should be arranged in the kitchen in such a way that work at one place does not interfere with work at another place, the distance between these places is not unnecessarily large, and no obstacles are in the way. A natural arrangement is a triangle, with the refrigerator, the sink, and the stove at a vertex each.
This observation led to a few common kitchen forms, commonly characterized by the arrangement of the kitchen cabinets and sink, stove, and refrigerator:
A single file kitchen has all of these along one wall; the work triangle degenerates to a line. This is not optimal, but often the only solution if space is restricted.
The double file kitchen (also known as galley or corridor) has two rows of cabinets at opposite walls, one containing the stove and the sink, the other the refrigerator. This is the classical work kitchen.
In the L-kitchen, the cabinets occupy two adjacent walls. Again, the work triangle is preserved, and there may even be space for an additional table at a third wall, provided it doesn't intersect the triangle.
A U-kitchen has cabinets along three walls, typically with the sink at the base of the "U". This is a typical work kitchen, too, unless the two other cabinet rows are short enough to place a table at the fourth wall.
The block kitchen is a more recent development, typically found in open kitchens. Here, the stove or both the stove and the sink are placed where an L or U kitchen would have a table, in a freestanding "island", separated from the other cabinets. In a closed room, this doesn't make much sense, but in an open kitchen, it makes the stove accessible from all sides such that two persons can cook together, and allows for contact with guests or the rest of the family, since the cook doesn't face the wall anymore.
Modern kitchens often have enough informal space to allow for people to eat in it without having to use the formal dining room. Such areas are called "breakfast areas", "breakfast nooks" or "breakfast bars" if the space is integrated into a kitchen counter. Kitchens with enough space to eat in are sometimes called "eat-in kitchens".