Exterior accessory dwellings create strong incentives to increase impervious surfaces and destroy trees (October 18, 2017)

The actual regulations may be different based on whether it is an interior or exterior AD. The interior ones refer to the actual square footage in the main/existing dwelling that is used for the AD. This square footage will be increased to 1,000 square feet (about the size of my basement or half the size of my house). When it comes to the exterior units, I don’t know how large the accessory building can be because staff won’t answer Martha’s question about how a “garage” will be treated.

You could build a 1,500 sq ft garage (or even larger) on your property if you have room for it. Of that 1,500 sq ft, only 750 sq ft can be devoted/allocated to an accessory dwelling unit. These changes don’t necessarily restrict the size of the exterior accessory building you can build, it just restrict the amount of space in that building that can be used for housing. It works the same way with the main dwelling. These AD zoning regulations do NOT govern how large a house you can build, they only restrict the amount of space you can use to create an AD inside your house.

CivFed did not have sufficient time to fully study the issue and there were some external complications that limited data collection. So the organization as a whole has not voted on a particular recommendation.

Personally, I do not object to the interior AD zoning changes. I strongly OBJECT to the creation of exterior ADs because

1) This change introduces a new, potent economic incentive to increase impervious surfaces accompanied by the loss of green space and mature tree canopy. Arlington’s remaining and ever-shrinking mature tree canopy resides largely on single-family lots. This measure undermines the county’s Urban Forest Master Plan and similar stated goals to preserve Arlington’s tree canopy and green space.

2) External ADs are highly likely to be used a short-term Airbnb-type rentals rather than being added to the long-term rental housing stock. For example, see “How Airbnb Short-Term Rentals Exacerbate Los Angeles’s Affordable Housing Crisis: Analysis and Policy Recommendations” http://harvardlpr.com/wp-content/uploads/2016/02/10.1_10_Lee.pdf. Staff has provided NO hard data or evidence to support the notion that ADs — either internal or external — will increase the affordable housing stock for those earning 80% or less of the area median income. They are likely to be just as expensive to rent as comparable market-rate units and may be even more expensive when they are located in highly desirable neighborhoods (e.g., close to Metro, within a sought-after school attendance zone, etc.).

3) Building additional exterior housing units in close proximity to the main dwelling and other dwellings increases the risk of fires spreading from one dwelling to the next. It also increases the chance of noise and other unwanted disruption to neighbors, negatively affecting their ability to enjoy their own properties and possibly reducing the market value of neighbors’ properties. Arlington County’s code enforcement staff works M-F, 8 am–6 pm, and there is no meaningful enforcement of code violations (including the noise ordinance) outside of those time periods.

4) How the Zoning Administrator and staff will ultimately “interpret” the new regulations governing exterior ADs is unknown. Many questions remain, and unexpected issues/conflicts concerning exterior ADs continue to crop up.

Here are your options as I see them:

1) Do nothing and live with the consequences.

2) Oppose the changes to the AD regulations and keep the existing regulations.

3) Oppose exterior ADs but support the changes for interior ADs.

I would not recommend trying to support or oppose discrete aspects of the proposed zoning changes, like the permitted square footage. Zoning is a highly technical subject, and you are unlikely to prevail on trying to attack the zoning changes on a piecemeal basis.

Just my two cents,