Upcoming County Board decision on Accessory Dwellings could have major impact on our tree canopy (October 18, 2017)

Dear Members of the County Board,

I am writing to oppose the proposal to allow exterior Accessory Dwellings (I have no objection to changes to the current regulations for interior ADs). Has the County Board considered the environmental impact of this proposal and its effect on the County’s ability to meet its goals for stormwater retention, tree canopy restoration, energy use reduction, or public health? 

This change will create a huge incentive for overbuilding on single-family lots, with serious environmental (in addition to aesthetic) consequences. In many neighborhoods close in to metro there is already precious little pervious surface. Lot coverage rules already do not apply to patios, walkways, or any other pavement that is not used as a driveway. Adding more buildings, with probably walkways and/or patios, will mean more stormwater runoff and loss of trees. This in turn will exacerbate flooding of neighboring properties, decrease air quality, make neighborhoods hotter, and increase energy consumption.

Because these new ADs can be used for AirBnB type rentals, they will be most desirable in neighborhoods close to Metro. Many of these neighborhoods–Ashton Heights, Lyon Park, Aurora Highlands–have been identified in inventories by the Urban Forestry Commission as having lost significant tree canopy in just the three-year period from 2008 to 2011. These neighborhoods have continued to lose large numbers of trees and gain impervious surface since then. 

Under current zoning regs, homeowners can be given an extra 5% of lot coverage if they put up a detached garage. Does this additional allowance apply to ADs that function as a garage plus living quarters?

Finally, allowing what is essentially a small house to be built one foot from the property line makes a mockery of zoning setbacks in single-family neighborhoods. 

If the purpose was to craft these regulations so as to maintain the character of single-family neighborhoods, then the provision allowing detached accessory dwellings should be scrapped.


Natasha Atkins