There is a lack of affordable housing in southern Maine. But it’s also a problem in the midcoast and Down East regions, as well as in central Maine and even up north in Aroostook County.

We tend to think that housing affordability is a challenge only in the overheated real estate markets near the state’s population centers, but research commissioned by the Maine State Housing Authority confirms that it’s not just a problem there. More than half the Mainers surveyed said they were less than satisfied  with the affordability of their current home, and almost a quarter said they have had to take on extra work to cover housing costs.

Half the people surveyed said that it has become more difficult for them to find affordable housing over the last three years – and these reports are spread out nearly evenly over all 16 counties.

Since all kinds of prices are driven by supply and demand, you wouldn’t think that Maine should have a problem when it comes to housing. Our population is the same, year after year, and what population growth we are experiencing is concentrated in a few metro regions. If there aren’t more people, why do we need more places for people to live?

The answer is that the number of people isn’t the only change that matters. As the population ages, household sizes shrink. Houses that were once home to big families are now left to older couples or individuals, who struggle to heat and maintain them. Almost 40 percent of Mainers surveyed said they would like to move, and the most popular reasons were to be closer to services and to have a smaller and more affordable home.

But that option is not available for everyone. Demand for in-town housing drives up prices, putting them out of reach of Mainers of modest means. That means more people are stuck in houses they can’t afford, isolated from community.

There is high demand for new affordable-housing projects, like the 64-unit West End Apartments complex in South Portland, which is currently under construction but has already received funding for a 52-unit expansion. Thirty-two thousand households are waiting for affordable housing, said Greg Payne, director of the Maine Affordable Housing Coalition. Yet, on average, only 214 new units of affordable housing have been built here annually in the last six years.

But it’s not just a matter of big projects. Respondents to the survey said they wanted to see zoning and regulatory changes on a local level that would allow smaller houses and accessory apartments as well as multi-unit developments in their towns. A number of people said they would be open to kinds of shared housing arrangements, which would not be allowed under current zoning in many areas.

The MaineHousing report should be a valuable resource for state and local planners as well as housing organizations that are designing communities that meet people’s needs. The lack of affordable housing is a statewide problem that won’t be solved without a statewide effort.