BOSTON -- Kate Crosby, a married registered nurse, wants a safe place where her 2-year-old son can grow up.

Nancy Wight, a software engineer who is married and planning a family, wants to be able to see her friends without getting out a datebook for an appointment two weeks in advance, hiring a babysitter and driving across town.

The two families are working to create a community in Acton, Mass., where they -- along with 20 other households -- will share evening meals, tools and toys.

This is cohousing, a burgeoning movement that began in Denmark and is slowly spreading in the United States. It is a type of cluster housing where homeowners preselect their neighbors and design their houses together.

There are two such communities on the West Coast and about 75 in the planning phase nationwide. In Massachusetts, a handful of groups are on their way to establishing model cohousing communities here, including one in Acton and another in Amherst.

Unlike the communes of the 1960s, cohousing participants are not drawn together because of a common ideological cause. Instead, these are people who have simply grown tired of isolated urban living.

And while cohousing may seem a "new" concept in American living, it is, in fact, a very old one. What attracts cohousing participants is a yearning for small-town life, a sense of community where neighbors know your name and your dog's name, too. Proponents say they want to build a place where people care about each other.

Although most of the cohousing groups are dominated by couples -- in their thirties with children -- who believe their lives will be easier and their children safer with the help of neighbors, it also appeals to older singles and child-free couples.

Take, for example, Audrey Child, 56, who is starting her own business designing knitwear. She likes living alone, but she misses the sense of community she knew growing up in a small farm town in Illinois. Child found the perfect compromise in the Pioneer Valley Cohousing Group in Amherst, where she will join up to 35 households in a planned community.

"I can have my own space and live alone and still have people around me who care about me and are good companions ... . I don't want to get into a relationship to have someone to live with," Child said.

The Pioneer Valley Group has its eye on a 23-acre site in Amherst owned by the town and designated for affordable housing. The group's preliminary site plan calls for 35 houses and, to date, 38 adults with a total of 17 children are interested in becoming part of the experiment.

The group wants to build all of the houses on six acres of land, leaving the remaining 17 acres open for recreation and gardening, said John Ryan, a real estate consultant who is a member of the Pioneer Valley group. It hopes to break ground next spring, if the proposal is approved at the November town meeting.

The New View Neighborhood Development Co., looked at 30 sites in 20 towns before finding an 18-acre location in Acton, which it is actively negotiating to buy. So far, 22 households have become members, and the group is hoping to bring the number up to 25 or 30.

The Amherst group's adult participants range in age from 30 to 67 years. Professions include an architect, real estate developer, engineer and attorney. In Acton, the group is also diverse with a chiropractor, software engineers and stay-at-home parents. Both groups said they want their cohousing to be ethnically mixed, but so far the Acton group has just one child of color and the Amherst consortium has one Latino member.

Many of the members found out about these cohousing groups from newspaper advertisements or through word of mouth.

Cohousing can be anything the group wants it to be. But certain elements are common. Houses are smaller than average and usually are attached to one another to save money and foster social interaction.

In Acton, architects will design nine single-family houses in addition to the cluster housing. Streets between houses are made for pedestrians only; cars are driven on the outside of the housing cluster and parked in a designated area.

A common house with a large dining room and kitchen for optional nightly meals is the central feature. Although individual houses will include kitchens, members will be able to skip cooking for themselves and join the group meals.

The common house often includes shared laundry facilities. In Acton, developers envision a common house with a children's play area, office space, storage for bulk food and a recycling center. Still on the wish list are a library, guest rooms, workshop, soundproof room for practicing musicians and a swimming pool.

Architect Peter Kitchell of Kitchell & Austin in Amherst, said working with a cohousing group is time-consuming because so many clients are involved in one project. But he said he prefers this to designing homes for the abstract "typical family" whose feedback is nonexistent.

"The people who want to do this ... are looking for a very rich life," Kitchell said. "They are singles and pairs and all kinds of sexual preferences and ages. It leads to some original and very valid new expressions of living together that we have to translate into buildings."

Kitchell said the houses in the Pioneer Valley group in Amherst will be 1,200 square feet, 5 percent to 10 percent smaller than the median house in Amherst. Each house will have a kitchen, dining room, bedrooms, bathrooms, porch -- but no garage.

Fences, low hedges and walks, sand boxes and ball courts will create a balance of public and private spaces.

The biggest obstacle to cohousing is simply finding the perfect site. Fewer than 10 percent of Massachusetts's 351 towns and cities have zoning laws that allow cohousing to be built without a variance, said Bob Engler, a Cambridge development consultant who works with cohousing groups.

"People want to put their houses closer together than the normal law allows, they want a community building and a child-safe area. And that's breaking a lot of local zoning laws," Engler said. "Most zoning laws don't allow that flexibility."

Once built, the Amherst homes will be individually owned -- either as a cooperative in which members own a share or as a condominium where members own the building but not the land under it, said Ryan.

Forming a cohousing group is a glacial-like process where members must learn to make decisions by consensus. That means every member must be able to live with each decision.

Is it worth it? "I don't know yet," said Wight, the software engineer, who devotes 10 hours a week to meetings. "I've made a lot of friends, and I've learned a lot ... . We spent a lot of time learning how to listen, learning to respect people's differences."

Yet the process itself is what knits strangers into a community. "It involves a great deal of commitment on the part of a lot of people. It is the process of defining the common vision of what you want ... which makes you feel you are part of people's lives," Ryan said. "We have created our community. We just need a place to put it now.