The state has granted final approval to the county’s plan for boosting the housing supply in West Marin and other unincorporated areas, where homes of all kinds are scarce, particularly affordable ones.

The state had already backed most of the Housing Element of Marin’s Countywide Plan, but in February requested more details about how it would advance fair housing laws that promote access to all people regardless of race, religion, national origin or disability.

Marin’s Community Development Agency then provided more details about its plans for investing in the lower-resourced neighborhoods of Santa Venetia and Marin City. The California Department of Housing and Community Development gave its final approval on June 19.

“We’re very pleased to have the state’s sign-off on our Housing Element so that we can focus on implementation,” said Sarah Jones, the director of the C.D.A.

The plan sets a goal of developing 3,596 housing units in unincorporated Marin. Of those, 1,734 must be affordably priced for lower-income households.

Facing an acute housing shortage, state officials have required cities and towns across California to find ways to increase their stock of housing, especially affordable housing. In the past, these targets have rarely been met, but county officials are hoping to come closer to reaching their goal this time.

The county has adopted policies encouraging the development of accessory dwelling units and townhomes outside the coastal zone. In coastal areas, development rules are more stringent and must be coordinated with the California Coastal Commission.

“One of the first things we need to do is get other key policies, practices and regulations in place,” Ms. Jones said. “A big part of that effort will be working with the coastal commission on amendments to our Local Coastal Program so that it aligns with our Housing Element.”

The acute shortage of workforce housing has prompted much debate and discussion in West Marin, where the county has imposed a moratorium on short-term rentals while it considers their impact on the year-round rental supply. It has also commissioned a study of the housing needs of lower-wage workers.