Under the proposal, Stonefield Development Co. would give the city the first floor of the parking garage and $1,000 a year. In 50 years, the entire $7 million garage would transfer to city ownership. In exchange, Stonefield gets the rest of the garage to supply the required parking for an office building it wants to build on a portion of the site.

A more efficient use of space is not possible, says the city, because the water table is too high for underground parking in the area, and the nearby Renton Airport precludes offices over above-ground parking. The city's three-parcel lot is valued at $180,900, according to King County Assessor's records.

The current proposal includes a provision that the public could park for free in the entire garage outside of business hours, or 25 percent of the proceeds if fees are charged. The agreement will be subject to council review later this fall.