Have you ever walked down an entire alley in Evanston? It often goes: garage, garage, garage, parking pad, garage, garage, then a house! These backyard houses are better known as “accessory dwelling units,” or ADUs. Per Evanston’s Guide to Accessory Dwelling Units, ADUs are “small independent housing units on the same lot as a standard sized residence with a kitchen, bathroom, and areas for living and sleeping.”

Accessory dwelling units, sometimes called coach houses or granny flats, could add affordable housing in Evanston. (City of Evanston photo)

In recent years, Evanston has increasingly become an ADU-friendly city. To advance Design Evanston’s focus on “good design” in our city, this two-part series explores ADUs from two angles – the macroscopic level of a neighborhood block and the microscopic level of one backyard. This first article, focused on city planning, examines the purpose of ADUs as a housing option in Evanston and how they relate to our city’s values of equity, sustainability and affordability. 

Under current regulations, ADUs are a relatively new housing type in Evanston. Prior to 2018, they were hardly legal in the city. While it was possible to build a detached “coach house” in one’s backyard, these units could only house family members and could only be built behind single-family homes. Then, in 2018, the city legalized the rental of existing ADUs to “non-family members.” 

This initial change in 2018 opened the door for broader reform. Evanston passed a preliminary ordinance in January 2020 that legalized the construction of ADUs behind any residential structure on a conforming property, among other policy changes. Next, the City Council passed a full-fledged ADU ordinance in September 2020 that relaxed off-street parking requirements, permitted different ADU types and adjusted height requirements. Though the city’s Plan Commission briefly discussed not requiring a fire sprinkler system in new detached ADUs, this discussion did not advance further and the regulation remained in place, which adds to the cost of ADU construction today. Despite this caveat, with the final ordinance intact from late 2020, The Washington Post highlighted Evanston as one American city which has successfully amended its zoning rules to better allow ADUs. 

When examining the question of “why ADUs” in Evanston, it is valuable to look at the mismatch between the sizes of “households” and “houses.” Per U.S. Census Bureau data, the mean, or average, household size in Evanston is 2.38 people. Further, 18,945 Evanston households are one- or two-person households, which equates to 66.4% of all households in the city. Contrary to these demographic trends, the size of America’s new single-family houses have gotten bigger since the mid-20th century. Approximately 40% of Evanston’s housing stock currently has three or more bedrooms. 

U.S. Census Bureau statistics are American Community Survey 2019 five-year estimates.
U.S. Census Bureau statistics are American Community Survey 2019 five-year estimates.

Further, Evanston has an aging population. According to Census Bureau data, 21.4% of Evanston residents are 60 or older, which is 4.8% higher than the city’s 60-plus population in 2010. Older people tend to live in smaller households in the United States, and 27% of adults aged 60 or older live alone. As a result, one of the biggest proponents of ADUs nationwide has been AARP (formerly known as the American Association of Retired Persons). Especially considering the housing size mismatch in Evanston, it seems sensible to allow for smaller units that better align with the housing needs and lifestyles of our residents, particularly those seeking to age in-place.

Further, ADUs are an affordability tool in high-cost cities like Evanston, especially in single-family residential districts. Per a 2020 report from Enterprise Community Partners, allowing ADUs in single-family zoned areas “can unlock underutilized land and potentially … could boost … opportunity for less-affluent, renter households, who have been excluded from those neighborhoods for years.” Given that land alone is prohibitively expensive in Evanston, building more homes per parcel is a step toward affordability

While ADUs are a step in the right direction, they are not the silver bullet that will single-handedly address the cost of housing in Evanston. Instead, perhaps our city should consider sensible zoning reform to permit various “missing middle” housing types, including (but not solely) ADUs.

By permitting townhomes, duplexes and triplexes in all residential neighborhoods, we could begin to alleviate growing housing pressures in a constrained local market, where the median home sale price went up by 14% in 2020. These reforms can be accomplished without permitting skyscrapers in every Evanston neighborhood, which is why people often refer to them as “middle” housing types – not single-family, but not out of scale with a surrounding residential neighborhood. 

Additionally, given the racist history of single-family zoning in the United States, housing reform to allow for ADUs and other “missing middle” housing types is an equity issue. As Richard Rothstein writes in “The Color of Law,” “to prevent lower-income African-Americans from living in neighborhoods where middle-class whites resided, local and federal officials began in the 1910s to reserve middle-class neighborhoods for single-family homes that lower-income families of all races could not afford.”

When considering Design Evanston’s commitment to “good design,” equitable neighborhoods that are accessible to people of all incomes, ethnicities, races and lived experiences should be a key component of this principle. ADU reform in 2020 was an initial step toward affordable housing in Evanston, though it cannot be the last if our city seeks to best act as a place of inclusion and welcoming. 

In summary, as we think about a few of the challenges facing the 21st century – wealth inequality and systemic racism – it is time to envision how to design neighborhoods that are resilient, diverse, democratic and collectively owned by the local community. Socially conscious design requires intentionality: proactive decisions about who is being included (or excluded) in Evanston based on the types of housing allowed. Permitting ADUs and “missing middle” housing types in our single-family neighborhoods can be one deliberate step in realizing a more-just city. 

For more information on ADUs, read part two: Designing an ADU.

Design Evanston’s “Eye on Evanston” articles focus on Evanston’s design history and advocates for good design. Visit designevanston.org to learn more about the organization.