Housing Elements Explained
Every eight years, the California Department of Housing and Community Development (HCD) requires state regions to assess housing needs for the following eight years. In the Bay Area, the Association of Bay Area Governments (ABAG) is the one that does the assessing.
Based on this assessment, ABAG assigns almost every town and county in the region – 109 governments in all – a quota of housing units they must accommodate, though not construct. This quota is split up into affordability brackets for various income levels, from Very Low Income to Above Median Income. (Corte Madera is the lone exception. It gets its quota directly from HCD, as the town has withdrawn from ABAG due to disgruntlement over the fact that ABAG assigned it affordable housing.)
To accommodate this quota, these local governments revise the housing element of their general plan. They list the sites that might accommodate affordable housing, send them to HCD for review and approval, and then amend their general plan if they receive approval.
The whole process is called the Regional Housing Needs Assessment (RHNA, pronounced “REEna”). If you hear someone talking about RHNA numbers, that’s the number of units assigned to a given area. If you hear someone talking about the RHNA cycle, that’s the regular cycle of assigning RHNA numbers, developing a housing element, and submitting it for approval.