The City Council approved the changes unanimously this week. The properties are spread across 16 of Madison’s 20 council districts, with most on the city’s far east and west sides. Most were assigned “low” or “low medium” residential zoning to reflect existing development patterns.

The change addresses problems with planned development districts, whose older, property-specific rules did not automatically update when the city revised its zoning code. Residents in those districts often faced extra review steps for projects such as decks, pergolas and egress windows that are allowed without additional approval in other residential zones.

The new zoning also extends city rules permitting accessory dwelling units and duplexes in many neighborhoods to the rezoned properties. Those projects remain subject to private homeowners association rules and other valid covenants, which the city does not enforce.

“What we’ve found over time with these districts is that their set-in-stone zoning text doesn’t change when Council changes our zoning code,” said Katie Bannon, the city’s zoning administrator, at a public meeting in June. She said outdated rules can make home improvements harder to review and approve.

Bannon described a case in which city staff spent nine months working with a homeowner seeking permission to build a shed. The homeowner had to track down people named in the district’s documents who could approve the project, but they did not act, she said. The city eventually had to change its zoning code to move the application forward.

The rezoning is not designed to substantially alter the uses or density allowed on the affected lots, according to a planning staff memo. Staff described the approach as a “horizontal rezoning,” rather than an upzoning or downzoning. In some areas where city plans envision denser development, the revised zoning still allows less intensive housing, with staff citing the existing low-density character of those neighborhoods.

That choice drew criticism from resident Nicholas Davies, who said keeping the zoning at lower density would limit opportunities for additional housing. He questioned why the city was not making more room for “missing middle” housing, such as small-scale apartment buildings.

Planned development zoning was widely used in Madison and elsewhere from the 1970s through the 2000s, giving developers flexibility to shape projects. The city conducted a major overhaul of its zoning code in 2013, and planners have used planned development districts less frequently since.

The city has posted a list of affected properties and maps organized by council district on its planned development rezoning webpage.