A series of recently-completed housing plans show a year-round population straining under the weight of rents and mortgages amid prohibitive building costs and the pressures of a seasonal real estate market.

Draft housing production plans — one for each town and one for the Island as a whole — represent the first major effort since 2013 to document the Island’s longstanding shortage of year-round housing and identify solutions.

The plans outline a number of strategies for expanding affordable year-round housing. They also include updates to a housing needs assessment issued by the Martha’s Vineyard Commission in 2013, which documented demographic and economic patterns.

On the mainland, housing production plans typically aim to give communities more control over state comprehensive permits under Chapter 40B, the state law designed to enable affordable housing projects. But on the Vineyard, where controls are already in place for comprehensive permits through the Martha’s Vineyard Commission, the main interest has been in improving long-term planning.

Consultants at JM Goldson of Roslindale drafted the plans, drawing largely from the five-year American Community Survey, which supplements the U.S. Census, the 2013 housing needs assessment and various town, state and federal sources. Planners also purchased a large amount of data from the Warren Group, a Boston marketing and research firm which compiles real estate and financial information for New England, including Dukes County.

Renters and owners alike on Martha's Vineyard are severely cost-burdened when it comes what they spend on housing. — Alison L. Mead

Updates to the housing needs assessment again highlight the struggle among renters with low and moderate incomes to find affordable housing (defined as costing no more than 30 per cent of an annual household income). The study finds that about a quarter of all Island households, both renters and owners, are severely cost-burdened, paying more than half their annual incomes on housing. Households with very low incomes are even more strained.

Small households were the most burdened, especially those earning the median income for Dukes County, about $64,200.

The plans also note a growing Islandwide population, with fewer rental and ownership opportunities. A projected 12 per cent growth in the overall year-round population by 2035 is expected to occur mostly down-Island, especially in Oak Bluffs. Chilmark and Aquinnah show an opposite trend. Projections for every town show more elders and fewer working-age residents. By 2035, the reports said, residents over the age of 65 may account for almost a third of the Island population, an increase of 148 per cent from 2010.

Between 2010 and 2014, the average household size on the Island increased from 1.95 to 2.86 people, while the total number of households fell from about 6,400 to 5,800. That suggests more people are living together, possibly as a result of higher housing costs, more multi-generational families, shifting cultural norms, or some combination of factors, according the Islandwide report.

Just under a quarter of all year-round households occupy rental homes, compared with more than a third in the state. And the number of people in nearly every age group with year-round rentals has declined in every town since 2010, often dramatically. In West Tisbury, for example, the number of renters aged 45 to 54 plummeted from about 70 in 2010 to zero in 2014. In every town, renters over 65 declined more slowly or showed an increase.

Judi Barrett of RKG Associates, who helped develop the plans along with JM Goldson, attributed the decline in renter households simply to a lack of opportunity. She noted that many properties that once contained rental units have likely been swept up in the seasonal real estate market and no longer serve the purpose.

“The big issue that makes all those towns different [compared to the mainland] is just the pressure of the seasonal housing market,” she said of the Island. And while each town could facilitate more year-round housing through amendments to bylaws, she said regulatory change alone will not solve the problem. “They need money,” she said. “The pressure of the seasonal market is too intense.”

Among year-rounders who own their homes, more than two thirds moved in prior to 1989. And the report states that houses passed from one generation to another often don’t stay in a family, given their high market value. In that case, they may end up as seasonal homes, which mostly remain vacant in the winter.

The median home value on the Island was about $660,000 — nearly twice the median value in the state. Overall, homeowners on the Island are slightly less affordably housed than renters, although renters are known to have the highest need in light of the shortage of rental housing.

Meanwhile, the cost of new construction has increased about 32 per cent since 2005, to about $734,300 for a single-family home. New residential construction has slowed in the same period. The report attributes the rising costs at least partly to a desire for larger and more seasonal homes.

As in 2013, the plans touch on the issue of homelessness, counting 47 individuals and eight families without stable housing in the first half of 2016, not including those displaced in the summer shuffle. People without stable housing face a tough challenge, the report notes, as they often lack the income, assets and rental history needed to sign a lease. The report adds that people without a home often have a history of addiction or other health issues. Compared to the state as a whole, Vineyard residents are slightly less likely to have a disability, according to the American Community Survey, although the report says that may simply indicate a lack of appropriate housing on the Island.

The housing assessment updates were delivered to town officials last fall. As part of the larger housing production plans issued two weeks ago, the assessments will now be subject to town review, with a public comment period open through Feb. 24. Final plans are set to be issued to Island towns in mid-March.