FOR MOST developers, density is the name of the game -- and often they can bargain for a little extra in exchange for certain amenities, such as landscaping or public artwork. But in Montgomery County, where such swaps have been routine, there's a new kind of deal being struck that could begin to help address a separate but not unrelated county issue: day care. The county's planning board has approved a $100 million retail and office mall in downtown Silver Spring under an arrangement that requires the developer to help plan, build and operate a day care center to serve employees in the redeveloping downtown area as well as those who live nearby. All sides seem to be pleased with the proposal.

The site in this instance is a 575,000-square-foot project planned where the Hecht Co. and adjoining buildings have stood. It's the first major retail proposal in more than 40 years for Silver Spring. County officials are hoping this project will revive this once-bustling commercial center. The child care arrangement calls for developers to support a 140-child facility to be built on county land near the downtown area. In exchange for this and other public improvements, the developers will be permitted to extend their project beyond standard limits.

It's important to note that the day care center idea came from the developers. It was they who first proposed building it in the retail/office complex. County planners favored a park in that space and suggested that the center be built on a county-owned lot at Spring Street and Second Avenue. The agreement includes a requirement that the developers operate the nonprofit center and pay a share of the program's costs. County officials hope to attract other developers who seek space in Silver Spring to pick up remaining costs.

Why not? When a useful facility can be created as a part of doing business -- with a specific site, with the agreement of developers and without adding burdensome costs or commitments -- the benefits can be attractive to the county and the developers as well as to the people they serve.