The report by the Massachusetts Audubon Society, New England's largest conservation organization, also finds that 40 acres of Massachusetts forest, farmland, and open space are being developed every day, about 90 percent of which is being used to build new homes.
Development of the open spaces that once defined New England's rustic image now threatens rare habitats from Cape Cod to the Berkshires, the study said, much like the pitch pine and scrub oak forests that once lined the Connecticut River Valley but are now lost forever.
The report, which is to be released today, paints a picture of increasing sprawl where Massachusetts residents live in large suburban houses and commute long distances to work, and a state where affordable housing remains in short supply.
"It's the `mansionization' of Massachusetts," said Jack Clarke, director of advocacy for Mass. Audubon, in an interview yesterday.
Home builders say they're being forced to build on larger lots by communities trying to slow development through zoning regulations. They say the lack of a statewide law for multiunit housing allows individual cities and towns to require costly improvements that encourage the construction of large, expensive homes to cover those costs.
The result, according to the report, is the construction of ever larger homes and lots. Between 1970 and 2001, the average living space for a new single-family home grew by 44 percent, from 1,572 to 2,260 square feet, according to the report. Over the same period, the average house lot grew by 47 percent.
That growth occurred despite the trend toward fewer people on average who actually live in those houses. In 1970, an average of just over three people lived in each Massachusetts household. By 2000, thanks in part to smaller families and higher divorce rates, that number had fallen to 2.5 people per home, the report found.
The Mass. Audubon report, titled "Losing Ground: At What Cost?," drew upon 30 years of tax assessor records and data on land use and open space, as well as aerial photographs by the University of Massachusetts at Amherst.
It found that between 1985 and 1999, much of the development of forested land took place in southeastern Massachusetts and on Cape Cod, home to some of the Northeast's largest remaining coastal forests. The Cape Cod town of Barnstable had the largest number of forested acres that were developed, the report found.
The loss of agricultural land was most noticeable along the Interstate-495 corridor and along the Connecticut River Valley, the report found. The town of Dartmouth, in southeastern Massachusetts, had the highest number of agricultural acres developed.
Statewide, more than 202,000 acres were developed between 1985 and 1999, the report found, an area roughly equal to the area around Boston within Route 128.
Kevin Breunig, the report's author, said the construction of new homes, businesses, and other buildings is not a problem in itself. The report points out that the state's infrastructure must accommodate its population, which grew from 6 million in 1990 to 6.4 million in 2002, according to the US Census.
The problem, Breunig said, is the type of development Massachusetts has undergone. Sixty-five percent of the land developed for new homes between 1985 and 1989 went to homes that are set far apart on large lots, the report found, which strains surrounding habitat more than smaller homes or multi-family units on smaller lots would.
"If you care about affordable housing, if you care about habitat, this is really bad news," Breunig said.
Despite the development trends, vast tracts of state land remain undeveloped. About 24 percent of the state's land was developed by 1999, compared with 17 percent in 1971, the report found.
Some home builders say they're responding to consumer demand for larger homes -- as evidenced by the persistence of high home prices -- and the rules set out for them by state and local officials.
The Home Builders Association of Massachusetts, which represents 1,600 builders, developers, and other residential construction professionals, has been pushing for a statewide law that would allow developers to build more houses or apartments in smaller "clusters," in return for the preservation of open space.
As it stands now, developers have to undergo arduous negotiations on a town-by-town basis to build smaller units, and many choose instead to avoid the negotiations and build larger homes that adhere to the town's minimum lot size, said Foxborough home builder Greg Spier.
Spier, president of Maystar Realty Corporation and vice president of the state Home Builders Association, said a subdivision he is now building in Foxborough demonstrates the problem. The 38-lot development on 100 acres of former farmland is in a watershed area where the town requires lots to be at least an acre and a half.
Because of the roads and other improvements required for a subdivision with such large lots, Spier said he had to build expensive homes to recover his costs. Homes in Spier's "Stonehurst" subdivision sell for $750,000 to more than $1 million.
"We call them McMansions," said Spier. "The only way for us to get our money back is to build large homes."
But in the long run, the state will ultimately have to pay for the loss of open space, said Breunig, the report's author. Water filtration plants will have to be built to replace the watershed lands that now act as filters, and dams and breakwaters will have to be built to replace the salt marshes and other wetlands that now serve as flood controls, he said.
In all, the study estimates, undeveloped land and recreational open space in Massachusetts provide services that otherwise would cost the state more than $6 billion per year.
"If we lose those lands that are providing those services, taxpayers would have to pick up the tab," Breunig said.
The report recommends that state and local officials act to protect critical habitat areas, preserve endangered species, and counteract sprawling development. It calls for more state money to buy forests, farmlands, and other open space, and it recommends a reform of state zoning regulations to remove loopholes that allow developers to bypass local review.
It also calls for state-level incentives to encourage denser development close to city centers and mass transit, and encourages cities and towns to enact zoning that allows developers to build denser housing while setting aside open space.
Clarke, of Mass. Audubon, said the goal is to recreate the density of the villages in which New Englanders traditionally lived. He said that would make Massachusetts a more attractive place to live and work.
"Businesses will pick a place like Massachusetts because of the quality of life," he said. "They're certainly not going to live here for the weather."
© Copyright 2003 Globe Newspaper Company.