Sustainable Communities Index

Indicator HH.1.a Housing production and affordability

Why Is This An Indicator Of Health and Sustainability?

High housing costs relative to the income of an individual or household result in one or more outcomes with adverse health consequences: spending a high proportion of income on housing, living in overcrowded housing conditions, accepting lower cost substandard housing, moving to where housing costs are lower, or becoming homeless. Spending a high proportion of income on rent or a mortgage means fewer resources for food, heating, transportation, health care, and child care. Sharing housing in crowded conditions can increase risks for infectious disease, noise, and fires. Lower cost housing is often substandard with exposure to waste and sewage, physical hazards, mold spores, poorly maintained paint, cockroach antigens, old carpeting, inadequate heating and ventilation, exposed heating sources and wiring, and broken windows. Moving away can result in the loss of employment, difficult school transitions, increased transportation costs and the loss of health protective social networks.  For additional information on the connections between housing and health, visit: The Case for Housing Impacts Assessment by SFDPH, Program on Health Equity and Sustainability. Accessed online on October 19, 2006: http://www.SustainableSF.org/etc/004_HIAR-May2004.pdf

Homeownership positively impacts the social cohesion and civic participation of a neighborhood, which in turn can impact health. Homeowners are more likely to feel invested in their community. They are more likely to participate in nonprofessional associations and vote in local elections. Additionally, a higher rate of homeownership in a neighborhood has been associated with fewer years of life lost due to cardiovascular disease for residents.^a

Methods

In order to calculate the percentage of housing production to housing demand by income category, SFDPH staff extracted housing production values through 2010 from the Association of Bay Area Governments’ San Francisco Bay Area Housing Needs Plan (2007-2014). Percentage of demand met was calculated by dividing the current production values by the estimated demand values for each income levels and multiplying by 100. 

Limitations

The RHND estimates housing demand based on future economic and employment growth and do not take into account unmet current demand for housing at all income levels. ABAG uses county-level area median income from the 1990 Census in its estimates of housing demand while the San Francisco Planning Department uses area median income for the San Francisco PMSA (includes San Francisco, San Mateo, and Marin counties) to disaggregate housing production data.

According to 2000 Census and 2005 American Community Survey (ACS) estimates, San Mateo and Marin counties have higher median household and median family incomes than San Francisco county. Thus using the San Francisco PMSA may overestimate housing affordability for San Francisco residents and underestimate the demand in very low, low and moderate income levels.

While housing demand may vary year to year with demographic and economic changes, ABAG estimates a constant annual demand within each period.