THE REGIONAL HOUSING NEEDS ASSESSMENT: NOT WHETHER WE GROW, BUT HOW. Southern California is going to grow. The SCAG region, which includes Orange, Los Angeles, Riverside, San Bernadino, Ventura and Imperial counties has a population of approximately 16 million persons. Using even a modest assumption of a two percent annual population increase, demographers estimate that the SCAG region will grow by more than 6 million people between 1997 and 2020. Even if there was no migration to the area, because of births alone, we will add 5 million people. For better or for worse, there are going to be a lot more of us in the future.
The Regional Housing Needs Assessment (RHNA) is a key tool for SCAG and its member governments to plan for this growth. The RHNA, when complete, will quantify the need for housing within each jurisdiction between 1998 to 2005. Communities will then plan, consider, and decide how they will address this need through the process of completing the Housing Elements of their General Plans. The RHNA does not necessarily encourage or promote growth, but rather allows communities to anticipate growth, so that they can grow in ways that enhance quality of life, improve access to jobs, transportation, and housing, and not adversely impact the environment.
The RHNA is completed periodically by SCAG and its counterparts in other parts of the state, as mandated by State law. It consists of two measurements of housing need:
The future need for housing is determined primarily by the forecasted growth in households in a community. Each new household, created by a child moving out of a parent's home, by a family moving to a community for employment, and so forth, creates the need for a housing unit. The housing need for new households is then adjusted to account for an ideal level of vacancy needed to promote housing choice, moderate cost and acceptable levels of housing upkeep and repair. In the SCAG region, many communities currently have more than the ideal number of vacancies, and thereby the vacancy adjustment is, in those cases, subtracted from the total housing need. Finally, a second adjustment is made to account for units expected to be lost due to demolition, natural disaster, or conversion to non-housing uses. The sum of these factors, household growth, vacancy need (generally a negative number), and replacement need, form the construction need for a community. Take a look at the RHNA calculator to see how this calculation of future need works.
To project growth, demographers examine historical growth patterns, job creation, household formation rates, and other factors to estimate how many households will be added to each community between now and 2005.
Take a look at the RHNA calculator portion of this website to see how this calculation of future need works.
Finally, the RHNA considers how each jurisdiction might grow in ways that will decrease the concentration of low income households in certain communities. The need for new housing is distributed among income groups so that each community moves closer to the regional average income distribution. You can see this adjustment in the RHNA "fair share" calculator.
The goal of this website, and the SCAG's goal for this RHNA cycle, is to make the RHNA useful and understandable for communities. As such, there is a RHNA calculator, which takes you step by step through the process of determining need. There are also collections of case studies, housing best practices, and sample Housing Elements, so that local elected official and planners can put their RHNA numbers to use in a well-considered way. Our aim is that the RHNA helps to ensure that, as Southern California continues to evolve, it will change for the better.