THERE IS GROWING evidence that child-care centers located in office buildings, factories and other places of work are good for the children -- and substantially improve the attendance and efficiency of the parent/employee. During the past few years, HEW, the Equal Employment Opportunity Commission and the Labor Department have been trying to encourage establishment of workplace day-care centers by private industry. As an incentive, the federal government offers tax breaks to businesses that establish such centers. Federal laws also allow Cabinet members to establish child-care centers for their employees. But the federal budget people now want to charge rent for the space the government provides for child-care centers, welfare and recreation associations, credit unions and the like -- and their effort may result in the closing of these child-care centers altogether.

In the Washington metropolitan area there are seven child-care centers in federal office buildings, serving about 350 youngsters; at least a dozen more are being planned. All of the activities are run by parents, who pay from $25 to $40 a week for each child --the going rate for nonprofit private child-care centers throughout the country. Tuition covers the cost of teachers, supplies, equipment, meals and, in some instances, maintenance -- but not rent. Space not otherwise needed is provided by the agency, as it is in many private businesses.

The federal rent proposal would require that agency directors determine that a child-care center is "essential for efficient agency operations" to qualify for space -- whatever that means. Yet these same agencies need only decide that cafeterias "maintain the welfare and the morale of the employees" before they are given space. Each center would then have to pay the going rate for office space and utilities -- as much as $9.25 a square foot in some instances. That means that the Labor Department's center, with 6,000 square feet of space, would have to raise its tuition to an unrealistic level just to pay the rent.

This proposal is too harsh. Perhaps the centers should pay a modest fee for space. But when extra rooms can be used for such an important purpose --and for programs otherwise paid for by those who use them -- the benefits clearly outweight the costs.