If you're working in limited space you have only two layout choices: the single wall and the corridor. The single-wall, sometimes referred to as galley, layout has all appliances on one wall. The corridor, or two-wall kitchen, places them on two parallel walls. The single- wall kitchen is the least efficient plan because you can't draw a work triangle in it. But this layout might be the only solution in a small apartment. Place the sink between the range and refrigerator. The refrigerator hinges should be on the side away from the sink so that the open door isn't an obstacle in the work area.
If you have a bit more space, a corridor kitchen is better than a single wall. Put two points of the triangle on one wall, and the third on the other. Place the refrigerator at the end near the main entrance to minimize traffic through the work triangle. (A work triangle comprised of the path between your sink, range, and refrigerator.)
If space is tight, but not too tight, the L-shape kitchen is the best choice. With the sink, appliances, and cabinets on two adjoining walls, this layout is far more efficient than the corridor kitchen. The triangle is compact, and you can keep traffic out of the way. The L shape is a perfect layout in a kitchen with a dining area. It allows for long stretches of counter space -- a plus for serious cooks or a two-cook team -- not interrupted by doorways or tall storage units.
Add an island to an L-shaped kitchen to get more counter and storage space. An island promotes socializing with people in adjacent areas. It becomes a bridge, connecting the cook and visitors.
In an L, one leg of the triangle is usually longer. Adding an appliance or fixture to an island can shorten it. But if the island takes up too much room, it can also be an obstacle. A cooktop or sink on the island can create a second triangle in a two-cook kitchen. If you're not planning to add an appliance, an island on wheels might be a useful alternative.
Of all kitchen layouts, the U shape is the most efficient. It puts a point of the triangle on each wall, making it more compact. A U offers more counter space per square foot than other layouts, with little risk of through traffic. This layout can accommodate a second cook if one of the legs of the U is long enough to contain a secondary sink or cooking center.
Of course, nothing is perfect. One disadvantage of the U-shape plan is the two corners, which are notorious for wasting storage space. You can avoid this problem, however, by choosing cabinets that make efficient use of corners. Another problem is the temptation to place work centers too far apart, since U-shape kitchens tend to be larger than most.