Thread by @salimfurth

#Upzoning versus #InclusionaryZoning: Who would win?

A lot of cities and states - like Florida (!) - pair permissive zoning with requirements that 10 or 20% of new units are set aside as deed-restricted affordable housing. Does it work? In New Rochelle, with a 10% mandate and upzoning to 48 stories, it did.
better-cities.org/wp-content/upl…

But in Somerville, Mass, with a modest upzoning and 20% requirement, it looks like the scale tilted the other way. Somerville boosted IZ in 2016 and again in 2019, taking it down to 3-unit buildings. It also upzoned in 2019.

Sadly, the city was negligent about replying to the Census Bureau's building permit survey prior to 2016, leaving zeros for several years. So we can't establish a baseline. But the trend is bad, except for IZ-exempt 1 and 2-unit buildings.

Placebo test: Does next door Cambridge show the same trend? Cambridge has a lot of issues, but there's no post-2016 decline in permits.

(There's one duplex and zero 3-4 unit buildings in the data. That might be a reporting problem; e.g. they're lumped into the 5+ group. The BPS is only as good as the cities make it.)

Lesson: If you *actually want* hundreds of deed-restricted affordable apartments, go Full New Rochelle and upzone to 48 stories with a 10% IZ requirement.

https://twitter.com/KarenHessel2/status/1643203734883778565

https://twitter.com/mattyglesias/status/1643263100907388929

For all the good stuff out of New Rochelle, follow @KarenHessel2

https://twitter.com/KarenHessel2/status/1642844209429331968

@KarenHessel2 P.S. h/t to @curcuas for putting Somerville on my mind and tipping me off to the extreme reach of its IZ ordinance.