NARRAGANSETT — Encouraging developers to build affordable houses alongside market-rate houses is a key goal for communities across Rhode Island as they try to comply with housing requirements set by the state.

Many towns are offering a sort of exchange, one that gives the developer more lots or “dwelling units” if some of the new houses, apartments or condominiums are subsidized and income-restricted, meeting the state definition of affordable.

The setup gives each side something it wants — the developer gets to build more units, and the town gets some housing units that are affordable.

In Narragansett, a different strategy is taking shape.

Rather than lure developers with more potential lots or units, the town would provide a mandate: If a developer is building six or more houses or “dwelling units,” at least one in five must be affordable.

The proposed ordinance, which received the first of two needed approvals from the Town Council on Monday, is something of a compromise.

For more than a year, the council went back and forth on a so-called “inclusionary zoning” ordinance that would have given developers a density bonus for building affordable housing. Town such as South Kingstown and Westerly have adopted that strategy, but council members and residents said increasing the density could change the character of Narragansett — already South County’s most densely developed town.

Last month, Councilman Christopher Wilkens offered a solution: Adopt an ordinance that requires developers to build affordable units but offers no density bonus. That way, the town would at least have an ordinance on the books, giving it some credibility with the state.

“I’m just looking for some way to break the logjam,” he said at the time. “We have to get something on board.”

Other council members quickly agreed, and several speakers have since praised the council for following through on Wilkens’ suggestion.

There is a nagging concern, however, and a speaker raised it at Monday’s council meeting.

Steven Glazer, a Planning Board member, said that without a density bonus the town, in effect, would be encouraging developers to submit fast-track “comprehensive permit” applications that seek greater density under the state’s Low and Moderate Income Housing Act. The law allows developers to seek waivers on a wide range of issues, including density, if one out of four units will be affordable.

“They will never go through the normal route if they’re just going to have to give up units,” Glazer told the council.

Council members acknowledged the concern but told Glazer they are looking for the Planning Board to be a line of defense for the town.

“That’s your job, to be difficult,” said Councilwoman Krista J. Garrett.

At least nine Rhode Island towns have adopted inclusionary zoning ordinances that require affordable units in at least some housing projects — Barrington, Burrillville, East Greenwich, Exeter, Lincoln, North Kingstown and Tiverton, in addition to South Kingstown and Westerly, according to the Statewide Planning office.

The list may grow — 26 of 29 towns that were required to prepare affordable housing plans listed inclusionary zoning as a strategy likely to be adopted.

Of the towns that have inclusionary ordinances, all include either a density bonus or some sort of financial incentive for developers to build affordable units, said Derry Riding, a state planner.

Housing is generally considered affordable when no more than 30 percent of a household’s income is spent on rent or on mortgage payments, as well as taxes and insurance. To be affordable in Rhode Island, a housing unit must also have income restrictions and it must rent or sell at a below-market price made possible through a subsidy.

State law calls for more than 10 percent of each community’s housing to be subsidized and income-restricted. Narragansett has 204 affordable units that meet the definition, which account for about 2.9 percent of its year-round housing.

The proposed Narragansett ordinance does allow the possibility of other “local subsidies” for developments that include affordable housing. The options include waivers on local sewer policies, waivers on local fees and tax abatements.

Whether that will be enough to entice developers or whether it will be too little, sending them down the wide-open path of the comprehensive permit, remains to be seen, Planning Board Chairman Terry Fleming said yesterday.

One route has a density bonus and one does not, “so I would expect that you would see, all being equal, developers use the comprehensive permit process,” he said. “Now if the other process is less of a burden, then maybe they would go that route. Hopefully they will.”

redgar@projo.com