In the Cambridge’s proposed Affordable Housing Overlay (AHO) the increased height and Floor Area Ratio (FAR) called for will impact neighborhoods in strikingly different ways. For example, up to 94% of buildings in zip code 02138 are two to five times smaller than the proposed 2.0 FAR and 1 to 3 stories shorter than the proposed height limit.[i] This will ultimately make such properties, previously considered as homes for working class and middle-income families, attractive development targets. The scale of buildings can be categorized into five different groups based on FAR and lot coverage. The below graphic succinctly illustrates the scale of each level of development intensity, as well as the potential negative impacts of unrestrained development “as of right” in every neighborhood, without normal rights of legal appeal
Map Below: Targeted sites in each zip code for 40 unit, 4 story tall AHO projects comprise very property over 10,000 SF. Properties between 5,000 SF and 9.99 K SF could be combined or used as is for 4 story projects with fewer units. FAR of 2.0 Impacts: Using Cambridge examples from the 02138zip code, the largest of Cambridge’s five zip codes with 3318 structures, reveals how changes to FAR limits can impact neighborhood density dramatically.
The map above shows the likely target area for larger Affordable Housing Projects (40 unit, 4 story structures). Here is a clickable map, you can see the buildings areas when you zoom in:
The light lavender background is the 02138 zip code where most of these large developments are slotted to occur also will be impacted far more because currently these properties have far LOWER FAR (density, Floor Area Ratio) then elsewhere in the city and a building with a 2.0 will represent a massive density and scale change here. See the graph below for the large differential impacts of a 2.0 FAR on the cities key zip codes. The lower the graph differential the more naturally a 2.0 FAR would fit in.
An FAR of 2.0 is universally reserved for large urban densities, not for other types of residential areas as the comparison below indicates.
Note that the planned Paris apartment community at the lower left has an FAR of 1.5 which is considered maximum for this kind of dwelling in most settings. AnFAR of 2.0 worldwide is intended for FAR MORE dense urban areas or structures – student dorms, large and tall apartment complexes, and office buildings. Key parts of residential Cambridge do not meet the criteria for 2.0 FAR found in other places like New York city, Mumbai, or outlying areas of Paris.
Group 1 (above): 0.20 to 0.49 FAR (410 structures) = 12% of buildings in 02138. These are primarily small 1 and 2 story structures on streets where the proposed 2.0 FAR for affordable housing up-zoning can be 4 to 10 times larger than the massing of current structures, with up to 40 new units replacing existing smaller homes.