After World War II, millions of garden apartments were built on millions of acres of suburban land in America.

Here was a type of housing that yielded urban densities, 20 to 40 dwelling units per acre -- in suburban settings. Garden apartments seemed to be the ideal compromise between more expensive, land-consuming detached houses or town houses, and high density, high-rise apartment blocks.

From the 1940s to the 1970s, garden apartment development was given additional impetus by the dramatic increase in population mobility and by increased highway building in, around and between cities. Long-term financing and FHA mortgage insurance for multifamily housing also were readily available. With low per-unit land and construction costs, plus low or subsidized interest rates, it was possible for landlords to offer apartments at competitive rents, affordable by a large segment of the American population.

Garden apartments, built in a variety of shapes and sizes, are often the first place of independent residence for singles entering the labor force. Many young married couples start out in a garden apartment. With limited incomes, families with small children may find garden apartments to be their most economical housing choice.

As developers increased project sizes, sometimes building hundreds of units on a single parcel, it became feasible, and from a marketing point of view, desirable, to provide collective, centralized recreational facilities. Such community amenities, intended to attract and serve tenants, could include swimming pools, tennis and other game courts, tot lots, playgrounds and recreational buildings containing meeting and party rooms.

"Rec" centers in apartment complexes could be like community town halls, the unique visual, architectural focal point in what might otherwise be an undifferentiated ensemble of buildings, lawns and parking lots.

For architects, designing garden apartments can be extremely easy or extremely challenging. If cost effectiveness alone is the primary goal, designers will use compact, efficient buildings of simple geometry, built of simple materials, and placed on their sites to maximize density and minimize sitework costs. Indeed, some architects do little more than repeat well-tested precedents that are easily adapted to varying site conditions.

Conversely, given a generous budget, a talented and imaginative architect might have little trouble devising an innovative housing scheme that is aesthetically rich and complex, one replete with various types of units, elegant materials, exciting spatial events and an elaborate facade.

But to design garden apartments that are cost effective and architecturally potent, that combine affordability with habitability, is one of the most difficult tasks an architect can face.

It requires thoughtful site planning and the development of well-formed and useful exterior spaces, which are the result of apartment buildings being composed in some orderly way to shape pleasant, garden-like landscapes or plazas. It requires struggling to make good facades with economy of means, choosing and combining materials carefully, and designing both workable and attractive construction details.

Of course, one of the thorniest design challenges is coping with the automobile. The easiest, cheapest and perhaps most convenient tactic is to park rows and rows of cars in front of rows and rows of apartment buildings. This allows residents to reach their building entrances after a few steps, something much appreciated during severe weather or after a trip to the grocery store.

But there are other approaches, which, while sacrificing some convenience, may produce better environments. Cars can be parked in smaller, more dispersed parking lots that are punctuated and surrounded by landscape elements. Apartment buildings can be configured to form car-free courtyards and gardens for entrance and passive recreation purposes. Structural elements -- trellises, screen walls, fences -- attached to or detached from the apartment buildings themselves can reach into the landscape to shape and contain parking areas or other exterior spaces.

Budget permitting, architects can employ carports to house cars and to act as pergolas. Stretching across portions of the site, they can act as strong visual links or edges. For more expensive apartments, garages might be in order. They can be treated as separate buildings or building wings that play a role in overall site composition. More often, however, they are under buildings, sometimes providing direct interior access to apartment units above.

In Sun Belt states, and especially California, you see the greatest variety of apartment configurations, mostly because of more liberal zoning laws and less severe climates. Complexes filled with intimate courtyards, often containing swimming pools or lushly planted gardens, are commonplace. Often, apartment buildings are geometrically complicated volumes of intricately assembled units, collages of diverse facade elements, roof heights and wall planes.

And there is no limit on style. Garden apartments can be colonial, neoclassical, Bauhausian, rustic or high-tech. They can be like Mediterranean villages or military academies. They can be formal or picturesque, domestic or institutional. Roofs can be flat or sloping, windows big or little, decoration minimal or profuse. Apartment buildings are, after all, big houses.

Yet despite both the difficulties and possibilities inherent in fashioning architecturally interesting garden complexes, tenants still might be concerned about the quality of their own apartment above all else. While perhaps creating a photogenic environment in which cars are under control, buildings are exciting to look at and garden settings are realized, the architect still must design a dwelling unit with architectural merits that are equally laudable . . . and marketable.

NEXT: The apartment unit.