Where will our children live?

''It's still a dream to have your own piece of property, your own house, and a sense of privacy,'' says Carl Jullie, city manager of Eden Prairie, Minn. ''But we have to learn to be more careful with our land use. We need to conserve the amenities we have and get along with smaller lot sizes, smaller houses, and more energy-efficient facilities.''

Single-family homes, once the definitive form of suburban housing, now account for only about 60 percent of all new residential construction in the US. Multiple units offer an increasingly attractive alternative to many people who cannot afford - or do not need - a single-family home.

Yet opposition to new housing styles still runs high. Suburban residents everywhere are digging in their heels, voting down proposed zoning changes that would allow a mix of housing.

Ironically, by preserving the single-family character of their communities, residents often exclude their own children. Nationwide, the average cost of a new house is nearly $90,000, well beyond the budgets of many first-time home buyers.

''We're at the stage in our suburban development where people who have grown up in the suburbs are now entering the job market and the housing market,'' says Nancy Reeves, housing director of the Metropolitan Council in St. Paul. ''They're finding they can't afford to live in their home communities.''

In a new public education program, ''Where Will Our Children Live?,'' the council underscores the critical need for more affordable housing. Among their suggested alternatives to single-family homes, they list:

* Town houses, or row houses: units constructed in a row, sharing common walls.

* Twin homes, also called duplexes and double bungalows: two homes sharing one common wall.

* Quadraminiums, sometimes called fourplexes or quadplexes: four-unit town houses that resemble a large home, giving each owner a corner unit.

* Manufactured housing: dwelling units assembled in a factory, then transported to their site.

* Patio homes: single-family detached units, often clustered so remaining land can be used as open space.

* Condominiums: any form of attached housing that allows each occupant to own a separate interior space but share ownership of the structure, common property, and land.

The council also urges communities to modify zoning regulations to make detached single-family housing more affordable. Recommendations include allowing development on 6,000- to 8,000-square-foot lots, removing minimum floor-area requirements, and not requiring garages.

But new construction can meet only part of suburban housing needs in the '80 s. Many older suburbs with little available land must look for creative ways to increase housing stock by using existing buildings. For them the ''three Rs'' have become: recycling, rehabilitation, renovation.

One of the most inventive forms of recycling - still illegal in many communities - is accessory housing: adding small rental units to single-family homes without making structural changes.

''It's so logical, and so unoffensive,'' says C. Richard McCullough, an architect in Medfield, Mass. ''Yet we're getting dramatic resistance to this. People think it means every house is going to be turned into an apartment. That's not true.''

He cites the advantages: ''The in-law apartment offers an independent life style for the elderly while providing the opportunity to live closer to one's children. It can also be a temporary residence for your own family, until they can afford their own home.''

A third group - divorced women - can also benefit, becoming either the owner or the tenant.

''When women become divorced, typically, they get the house in the settlement ,'' says Ruth Price, a planner with the Connecticut Department of Housing. ''Their incomes drop rapidly. They're going out into a job market where they often don't have skills. They're stuck with a life style that has radically changed, and they're under pressure to stay where their children are in school. Yet it's more and more difficult to stay in their communities.''

''It's not only a sociological imperative,'' Mr. McCullough says, ''it will probably be an economic necessity. Even a young family can probably afford to buy one of those older homes with an accessory-use apartment to help reduce the monthly payments.''

Not all the advantages are economic, of course. What planners call ''life-cycle housing'' - providing a variety of housing types within a neighborhood - enables residents to stay in the community as their housing needs change. Young people can rent an apartment until they can afford a single-family home. Older people, frequently ''overhoused'' after their children leave home, can move to smaller quarters within the same community, maintaining friendships and roots.

''If there's any lesson I see the suburbs learning,'' Nancy Reeves says, ''it's the importance of life-cycle housing. It allows housing to turn over, continually revitalizing communities. That's going to be better for all of us.''