Units in Residential Structures
American Community Survey (ACS), 5-year estimates, Table B25024
2011, 2012, 2013, 2014, 2015, 2016, 2017, 2018, 2019, 2020, 2021
*Note: Each year of available data shown above is a 5-year estimate, or an average of data collected over a five year period. 5-year estimates are used to increase the reliability of the data at small geographies like neighborhoods and census tracts. The years shown on the NDSC map represent the final year of the five year average (e.g. “2010” represents 2006-2010 data, “2011” represents 2007-2011 data, and so on). For the most impactful comparison of data over time, the ACS recommends comparing non-overlapping years (e.g. 2010-14 with 2015-19).
Why are these variables important to measure?
Homes with exactly one unit are known as single-family units. Fully detached, semi-detached, row houses, duplexes, quadruplexes, and townhouses are all examples of single-family buildings. In order to be considered “single-family,” structures must have a ground-to-roof wall separating them, a separate heating system, individual public utility meters, and no units above or below.
In contrast, multi-family units are units with more than one unit within the same structure. For example, multi-family residential structures often feature multiple stories, side-by-side construction without a wall from the ground up, or shared amenities/utilities.