Posted on January 30, 2006
New single-family home construction in the greater Boston metropolitan area is consuming about twice as much land as existing single-family housing, and half of the region’s 30,387 recent new single-family homes were built on lots of nearly an acre or larger, according to a new study by the Massachusetts Housing Partnership (MHP) and the MIT Center for Real Estate (MIT).
Although the image of quaint New England towns calls to mind homes on small lots, the region’s median lot size for new construction is now three times the national median. In addition, the metropolitan area’s median new single-family lot size of nine-tenths of an acre is twice the median size of houses built in the area during the 1970s and 1980s.
Using data supplied by The Warren Group, along with data from county registers of deeds and city and town assessors, MHP and MIT examined all new single family and multi-family housing built in the 154 cities and towns within or close to I-495 from 1998 to 2002, and then compared the density of new construction to existing housing density in each city and town.
The study found that the phenomenon of increasing suburban land use per dwelling is almost universal. One hundred and eighteen out of 123 communities outside of Route 128 with new construction produced housing on lots averaging larger than they had prior to 1998. Sixty-two communities outside of Route 128 had average lot sizes more than double those places’ historic densities.
The MHP-MIT analysis, which will be updated annually, fills a crucial gap by providing information not previously available. “Given the widespread discussion of land use, affordability, and commuting costs, we were surprised that no one was keeping score on what was actually occurring,” said Henry Pollakowski, Director of the Housing Affordability Initiative at the MIT Center for Real Estate and Editor of the Journal of Housing Economics. And the results added additional surprise. “We knew that many towns had adopted large-lot zoning regulations, but we did not expect to see lot sizes this large and the practice so widespread. We were also quite amazed by the recent growth in lot sizes. We’re not saying we expected towns along I-495 to start to look like Cambridge, but we were surprised to find the extent to which these towns today haven’t even held to their (very low) housing densities of a decade ago.”
MHP and MIT found that the 30,387 single-family lots developed from 1998 to 2002 used 39,890 acres (62 square miles) of land, resulting in an average of 1.3 acres per lot. This is an amount of land equivalent to the size of Boston, Brookline, and Arlington combined. While the MHP-MIT study does not proscribe “optimal” new housing densities, the study emphasizes that these patterns are out of line with even recent experience, and far out of line with national patterns. In the Western US, often considered the home of “sprawl,” the typical new house is built on about one-quarter of an acre of land. In the South, where land prices are lower, the typical lot is one-third of an acre.
“It is well known that we are producing far less housing in Massachusetts than needed to sustain our state's economic growth," said Clark Ziegler, MHP’s executive director. "This new data shows that we are squandering land on large house lots and missing opportunities every day to provide more housing while preserving open space and respecting our New England character.”
The MHP-MIT analysis follows a November 2005 MHP-commissioned study by economist Edward Moscovitch that estimated that Massachusetts could reduce its land consumption and cut home prices by $100,000 if it adopted tighter smart growth zoning patterns.
Moscovitch, president of Cape Ann Economics, found that if development in the Rt. 128-495 corridor followed the national smart growth pattern of .25 acres per unit, it would be possible to cut vacant land consumption almost in half and drive down average home prices in 2003 dollars from $400,000 per unit to $293,000. For more on that study, click here.
The MHP-MIT analysis also examined all recent multi-family condominium and rental units. The amount of land each multi-family dwelling consumed was considerably less than for single-family housing, with the median multifamily unit consuming an eighth of an acre as opposed to nine-tenths of an acre per unit for single-family detached housing. This number partially reflects the higher-density multi-family dwellings built in the more urban and historical dense communities inside of Route 128. Outside Route 128, the median amount of land used for multifamily construction was one-fifth of an acre per unit .
The study notes only one out of four communities outside Route 128 had any multi-family developments of five or more units during the period 1998-2002. The study also finds that condo developments account for considerably more land use per unit than rental apartments. This is particularly striking outside of Route 128, where the new median condo consumed one-third of an acre, compared to one-tenth of an acre for the median apartment..
To view maps that illustrate Greater Boston’s increased land consumption for housing, and related studies on land consumption and housing affordability, go to www.mhp.net or web.mit.edu/cre. Also available soon on MIT’s website are maps of recent development for each town in the metropolitan area. These maps show, for each town, the location, size, and type (single-family, condo, rental) of all individual housing units recently built. These maps and the statistics drawn from then will be updated annually, and are available free of charge to the public.
For more information, contact MHP's Ruston F. Lodi at (617)330-9944 x227 or Henry O. Pollakowski of MIT's Center for Real Estate at (617) 253-3703.