Rabbit hutch or doll's house? What best describes the Japanese home? With little doubt, all mansions or age-old country homes are somewhat small in Japan today. The matter can be put in some perspective if one considers the problems attendant upon placing half of the population of the United States into the area known as California. The space available to each Japanese family is plainly restricted.

Despite the inconvenience and a wistful desire for more room, today the Japanese live very well. A chemist recently described the country as, like the United States, one with "almost a classless society." Most Japanese consider themselves members of the middle class. A new term, "unmarried aristocrat," describes bachelor men and women who spend to the hilt, living well, dressing well and traveling widely.

Equal pay for equal work is not the norm, despite the advances made by women. It generally is assumed that they will work only until they marry. Nevertheless, a woman graduate of an ordinary university enters the work force at about $400 a month -- plus transportation, plus a summer bonus of two months' salary, plus a year-end bonus of three months' salary as well as other, more familiar, fringe benefits.

Changing times have raised the average pay of all workers (excluding benefits for retirees and excluding the unemployed) to about $12,000 a year with the bonuses.

The problem they face is space -- the Japanese feel cramped. Considering the international scope of today's economy, it is easy to anticipate that all Japanese might eventually be one extensive megalopolis!"

The doll houses already sit eaves-together or are stacked tightly together in multistoried apartment buildings. Up the Japanese can go, but with a wary eye on the structural problems of an earthquake-prone area.

To have a larger place, at an affordable price, young people move out from town, enlarging the metropolitan areas to a frightening degree. For a Tokyoite, such a move now necessitates commuting up to two hours each way with from one to four changes per trip. Fortunately, Japanese trains are fast, efficient and clean. But spending four hours a day sitting or probably standing on a train is a big price to pay for a bit more room.

Several urban universities recently have been moved to or are currently relocating in rural areas. This has turned them into more expensive residential institutions, but it does remove thousands of daily commuters from the capital's heavily burdened transit system. Companies, too, have considered this change, but nowhere is a decision to relocate an easy one for the employes.

Yet in middle suburbia, Japanese houses are increasingly comfortable and well-equipped. A wall, entry gate and tiny entrance yard hint a welcome. A look outward shows that only 12 to 18 inches separate the house from its surrounding wall, and a window nuzzles a neighbor's closed shutters. Nevertheless, many of the new homes have stolen from the ground floor enough space for a car, usually in the form of a carport, its roof the floor of the room overhead.

Cars are everywhere; dealerships and used car lots are encountered at every turn. Parking is a problem, because residential streets usually are only a lane wide. The going rate for a space in the outskirts is $30 monthly, but parking areas in the heart of Tokyo command $100. Surprisingly, considering the clamor for housing, tiny six-car lots are sprinkled about the residential areas. New apartments are built with parking spaces at ground level or in adjacent courtyards, which double as playgrounds.

Where once mansion and hotel existed side by side in Japan, the newer neighborhoods exhibit more economic cohesiveness. Today a home with three tatami rooms, one Western room (hardwood flooring and overstuffed Western furniture), kitchen, bath and carport will run about $205,000. A four-room apartment with kitchen and bath will sell for $130,000.

Financing varies, with ordinary bank loans running very high. The better (bigger and more prestigous) companies underwrite home loans for their employe, in whole or part, as a fringe benefit. Interest rates can be as low as 4 percent for a 20- or 30-year mortgage.

Within the home, evidence of an affluent society is widespread. Automatic washers, most commonly with cycles that allow the reuse of water and soap, are increasingly common. In apartments, their connections sometimes are built onto the balconies for want of interior space. Dryers are less common and doubtless will remain so until the stacked combination units are better developed. Laundry still sprouts from windows and balconies almost daily, because the capacity of the washers remains small, befitting the space available.

Where 20 years ago two-burner propane stoves and even charcoal braziers were commonplace, today one finds homes with ranges featuring two burners and a grill on top and a small oven below. Refrigerators have grown from undercounter size to apartment size, with a good freezer area. To supply them, markets now provide not only frozen vegetables but imported goods such as Sara Lee pastries.

Electric griddles, toasters, coffee makers, blenders and the ubiquitous rice cookers are in many kitchens. Today's rice cooker has an added advantage over older models; it keeps the cooked rice warm overnight. The potato has become almost standard fare in some households.