Boise Population Growth: The Housing Analysis relied on Census data to determine population growth from 2010 to 2019, which includes the annual American Community Survey updates of the decennial census count. During that decade, Boise City saw an average 1% growth per year, including a 0.8% growth from 2018 to 2019. Ada County saw an average 2% growth, including a 2.36% growth from 2018 to 2019.
Accordingly, the Boise Housing Analysis assumed that a 1% population growth in the City of Boise would continue for the next decade.
The analysis only looked at Ada County and did not consider migration patterns with other counties. It is well-understood that housing is a regional issue and that households will make decisions based on affordability, even if that means traveling across county lines.
The Work of Others: We conducted a literature review of available data for Ada County and City of Boise as it related to housing, demographics, and special populations like people experiencing homelessness, students, refugees, and seniors. COMPASS provided a demographics report (Demographics Quick Guide – July 2019) that acted as quality assurance for projections using Census data. A separate study on the Boise Area of Impact estimated that the housing need for additional housing units by 2025 would be 2,366 units per year. Data points like these offered a test of the assumptions in this study.
To understand the current market’s delivery of housing units, the analysis used COMPASS’ open-sourced data on building permits to estimate the number of units coming online in the last few years. This allowed a comparison of the housing need compared to the current delivery of newly constructed units.
Methods: When considering how to estimate housing demand, we considered past approaches (including Agnew::Beck’s own study in 2014 for the Boise Housing Needs Analysis). Our conclusion was that housing studies did well in considering how population growth (or retraction) impacts housing need over time. These studies also understood churn – housing units being taken off the market through disrepair or other methods. It was concluded that a majority of housing studies were missing other important characteristics that impact need for housing units and information for policy makers.
Specifically, the analysis looked at the following characteristics to influence housing demand: