May 26, 2022.
The Missing Middle Housing Study: Phase 2 Analysis and Draft Framework discounts the impact of up-zoning on Arlington’s tree canopy.
Even worse, Daniel Kuhlmann reported greater price inflation in recently up-zoned moderate income Minneapolis neighborhoods than upscale neighborhoods. Thus even if more housing units are produced, it’s up and out for renters who can’t leverage the additional rent and homeowners who can’t pony up the additional property tax.
Among its key findings are: “Given adherence to single household lot coverage and setback standards, environmental management tradeoffs would be limited.
• Stormwater runoff would be comparable to current impacts from single detached redevelopment
• Tree canopy of 20% to 50% is achievable [even though] minimum canopy requirements set by state code would be 10% or 15%, compared to 20% minimum for single detached (p.23).”
This happy prognosis is belied by current practice. On redeveloped properties in residential neighborhoods throughout the county, the site is routinely clearcut before the building is demolished. Replacement trees are sometimes planted, but they are saplings with none of the many environmental benefits of mature trees.
The result will be more runoff and flooding, bigger heat islands, less carbon uptake, shade and wild life habitat and a diminished quality of life for everyone in the neighborhood.
Still the county argues that the impacts of up-zoning will be negligible, because only 20 lots a year will be redeveloped under the new zoning rules (p. 19). Even if that were true, it does not take into account the cumulative impacts of up-zoning, including the gradual erosion of mature tree canopy.
The County believes that the impacts of up-zoning are offset by the increase in affordable housing. But the prospect of more affordable housing is illusory, because densification will inflate land values in redeveloped neighborhoods, driving assessments up and moderate income earners out.
Evidence of this phenomenon was surfaced in 2018 by Andrew Dobbs, who used a hypothetical up-zoning in a typical Austin neighborhood to demonstrate that the income derived from a redeveloped residential property together with the market capitalization rate for that area dictated an increase in the property’s assessed value of 18 percent. Dobbs concluded that simple math “shows why an obsession with heedless rezoning residential neighborhoods for so-called “Missing Middle” housing poses a real risk of making a bad situation even worse.”
Bottom line. Densification of an already overheated housing market may produce more housing for some residents at the expense of low income residents and the overall quality of life.