Three inner-ring Twin Cities suburbs that opened the doors to higher-density housing in recent years have seen slower redevelopment than some residents feared.

Just a handful of proposals have come through city halls in Roseville, Richfield and Bloomington since those cities started allowing duplexes, and none have yet been built. Residents had worried about rapid change, and feared their neighborhoods would quickly be overrun with run-down rentals and too many cars.

The suburban changes were more incremental than the zoning St. Paul passed Wednesday, which will open up the possibility of developing up to four units on many residential lots. City planners there did not expect overnight change, but hoped for more affordable homes in the long term.

So far, progress toward developing duplexes in the suburbs has been slow-moving, and some have required city-owned land or other public intervention.

"This was unlikely to happen on its own, at least at first," said Julie Urban, Richfield's assistant community development director.

When Richfield sold two pieces of city property this summer, Urban said, the city noted a preference for buyers who would build duplexes.

Urban said both buyers intend to build duplexes and live in them with members of their extended families in the second unit.

Neighbors who attended city meetings about the duplexes were concerned about preserving trees, and worried about having a neglected rental house in their neighborhood.

"There's always some fear about, is it going to become a rental property?" Urban said. "I think they equate rental property with poorly maintained."

When zoning changes were proposed in Bloomington in late 2022, the idea of more density and rental homes made some residents nervous. Residents of a west Bloomington neighborhood mobilized to speak for hours at city meetings, and even hired a land-use attorney to draft an alternate proposal. But Bloomington's city council passed the changes, allowing for smaller minimum lot sizes and making it easier to get duplexes approved.

So far, two projects have started moving through the permitting process, Bloomington Planning Manager Glen Markegard said.

One project is on Overlook Drive, where some of the city's largest houses look out on the Minnesota River valley. Earlier this month, Bloomington agreed to sell what had been a city-owned, single-family house on Park Avenue in east Bloomington to a nonprofit developer.

The zoning changes mean the Park Avenue lot can be halved. The developer has proposed that each half get a single-family house, and an accessory dwelling unit or guesthouse.

Urban said the proposals so far have been promising, but she expects future duplex development to be more difficult without help from the city in the form of low-cost lots.

Cities used to more easily buy run-down houses to sell to developers, Urban said, but house flipping has sharpened competition for most inexpensive houses.

"Now anybody will buy a crappy home, put some lipstick on it and flip it," Urban said. "So it gets harder and harder to find those opportunities."

In Roseville, where zoning changes were approved in 2021, one major duplex development has stalled.

A year ago, Roseville approved a development that would have seen two single-family homes torn down to make way for three twin homes and a smaller single-family house — a total of seven homes on newly-subdivided lots.

Roseville's 2021 zoning changes opened the door for that proposal, and neighbors worried about what it would mean for the community they prized for big yards and relative quiet.

But the development has stalled, and the developer could not be reached for comment. Roseville has not so much as issued demolition permits for the two houses.