An inflammatory article by Eric Scigliano takes Seattle's recently adopted Housing Affordability and Livability Agenda (HALA) to task for its lack of attention to the urban forest. Scigliano is clearly speaking for the trees, but in doing so also sets up a polarizing exclusion: "HALA is still a density agenda," writes Scigliano. "And density, absent special protections, is the mortal enemy of trees."

Speaking to that parenthetical caveat, Scigliano adds that the mitigation measures allowed by the city to substitute for the open space necessary to grow trees (i.e., setbacks, balconies, and green roofs) are a poor substitute for the real thing. (via Planetizen)

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Even with its most controversial provision – the elimination of single-family zoning – deferred, HALA is still a density agenda. And density, absent special protections, is the mortal enemy of trees. The city, in its development standards, has tried to defy the laws of geometry by allowing other mitigating measures that take less space but are less effective – setbacks, balconies, bioswales, green roofs – to substitute for the open space where trees can grow.

But trees get in the way when soaring prices induce developers to max out their lots, and the city to allow more housing units in the hope (vain so far) that supply will outrun demand and hold prices down. “The problem is lot coverage and setbacks,” says one veteran Seattle arborist who has fought for years on behalf of stricter tree protection, but insists on anonymity for professional reasons. As the city grows, “there simply isn’t enough space for existing large trees.”

The HALA agenda will accelerate this process by loosening coverage and setback restrictions, and upzoning targeted single-family areas near transit and city-designated urban villages. But the process is already proceeding apace under current zoning, as developers raze smaller homes and what few unbuilt private plots remain. Surging development has already stalled, maybe reversed the much-hailed growth of Seattle’s canopy during the preceding three decades.1

• 1. http://crosscut.com/2015/10/saving-seattles-trees-may-mean-saving-their-yards/