Appendix

Using population rates over the last decade, estimate housing need based on population growth rates projected out 10 years. Also, the estimate includes the units needed to achieve a 5% vacancy rate, which is considered a healthy housing market.

Data source: U.S. Census and American Community Survey

Some housing units will require replacement in the coming decade due to several factors. Three factors, tracked in Census data, provided perspective to this analysis: (1) Units without plumbing and kitchen facilities; (2) Units built before 1949; (3) Mobile home units. The analysis assumed that only a small portion of these units will need to be replaced.

Data source: U.S. Census and American Community Survey

In today’s market, there are housing units that have multiple households crowded into one housing unit. This creates unhealthy conditions for those households. Census data tracks the number of people per bedroom, which allows for an estimate of severely crowded housing units, defined by more than 1.5 people per bedroom on average. Data suggests that 0.6% of Boise housing units meet the definition of severely overcrowded. The analysis assumed that additional new housing units are needed to address the overcrowding that currently exists and provide adequate housing for the number of households in the market.

Data source: U.S. Census and American Community Survey

Some households in every jurisdiction do not have homes; the current housing market is not serving them. Also, the U.S. Census traditionally underreports people experiencing homelessness, due to the barriers in reaching this population. Accordingly, the analysis relied on estimates from the Homeless Management Information System to estimate the population without housing. And then, through interviews with the Corporation for Supportive Housing and Our Path Home providers, estimated that 30% of the homeless population was not counted in our Census estimates.

Data source: Homeless Management Information System and Key Informant Interviews

Households spending more than 30% of their total household income are “costburdened.” 22.7% of owner-occupied households and 44.7% of renter-occupied households in Boise meet the definition of cost burdened. Spending a larger portion of your household income on housing limits the amount of income available for other non-discretionary spending, such as food, clothing, and transportation. This updated analysis has a revised approach to capturing the need of cost burden households, and instead of increasing the total number of new housing units needed, the updated methodology takes a more granular approach by identifying the amount of new homes that will be needed at various price points to better meet the needs of households in Boise. This approach assumes that as more affordable housing units get added to the market, households that are currently cost-burned will move into units that are more financially sustainable, opening up their existing units for higher income households to live in.

Data source: U.S. Census and American Community Survey

The income that the median household makes, meaning that 50% of households of the same size earn less than the median household and 50% of households earn more than the median household. The median income changes based on household size.

A type of affordable housing that is primarily targeted to an extremely low income population and has a need for supportive services. This housing combines affordable housing with dedicated supportive services either delivered on-site or off-site of the property. Supportive housing primarily serves households exiting homelessness.

By housing unit: Any housing unit that has a rent or mortgage that is affordable to a household earning less than 80% of the area median income. Often the property will include a government subsidy, either for the capital costs or to assist with the rent. There could be a need for dedicating supportive services to the property, depending on the population housed.

By household: Housing is considered affordable to a household if they are paying 30% or less of their income to housing (either rent or mortgage).

A type of housing targeted for those earning between 80% and 120% of the area median income. This housing is meant for our “workforce” but can be a misleading term. With stagnant wages, “workforce housing” is better thought of as a type of market-rate housing, because it is largely unaffordable to much of the service-based workforce.

Any housing that has a rent or mortgage that is only affordable to those earning the median wage and above. There are no rent restrictions on the property and often no government subsidies.

The amount of financing needed to fully fund the development of a housing project after the primary sources have been identified and secured.

For the purposes of this analysis, missing middle housing represents any development of accessory dwelling units or small-scale multifamily units between 2-12 units in size.