MADISON, Wis. — Madison is developing zoning rules that would allow some data centers while restricting where they can be built and how large they can grow. The preliminary framework from the city’s Department of Planning and Economic Development divides data centers into small, medium and large categories and caps buildings at 100,000 square feet. Large facilities would be confined to industrial areas. The proposal is designed to exclude the enormous hyperscale centers and multi-building campuses that have become a focus of national debate. Dominic Parker, a professor of applied economics, said the facilities contemplated under the city’s approach would be much smaller than the projects often discussed in news coverage. Limiting their scale could also reduce potential economic gains, including jobs, property tax revenue and sales of vacant land, he said. The rules could help limit some of the impacts associated with larger operations. Parker said research has found that homes near data centers can lose value after construction, with noise and other effects on neighborhood quality of life among the concerns. In a statement, the city said the draft followed months of research. It would require noise mitigation and keep large facilities in industrial areas. Medium and large data centers would also have to be separated by at least 1,000 feet. City officials planned to seek feedback from residents and local business committees through the end of October. The zoning ordinance was expected to be formally introduced to the Common Council in November, with a final vote anticipated in January.