Floor Area Ratio has longed been used as a way regulate building density under zoning laws. The owner of the property can choose to build a short building on most of the property or a taller building on less of the property.
Although Floor Area Ratio has been used to regulate commercial properties, there was some uncertainty as to whether you could use it for single family residential property in Massachusetts. Floor Area Ratio restrictions is one way to limit McMansions.
In the case of 81 Spooner Road LLC v. Town of Brookline (SJC-10104), the Massachusetts Supreme Judicial Court ruled that towns and cities can use Floor Area Ratio to regulate the density of single-family residential properties.
The uncertainty comes from M.G.L. c.40A, §3 that provides in part:
“No zoning ordinance or by-law shall regulate or restrict the interior area of a single family residential building . . . provided, however, that such . . . structures may be subject to reasonable regulations concerning the bulk and height of structures and determining yard sizes, lot area, setbacks, open space, parking and building coverage requirements. . . .”
The Massachusetts Supreme Judicial Court ruled in part:
“that regulation of single-family residences pursuant to the authority in the proviso of G. L. c. 40A, § 3, second par., including bulk regulation by floor-to-area ratio, is a proper exercise of the zoning power, provided the effect of such regulation on the interior area of such structures is incidental. Although the town’s bylaw requires consideration of gross floor area of single-family residences for purposes of calculating floor-to-area ratio, this is not a prohibited direct regulation of interior area. Its effect is only incidental.”