FAQs

The Alliance for Housing and Climate Solutions (AHCS) created the Common Ground Learning Series to foster dialogue, expand knowledge, and build trust among environmentalists and housing advocates. 

Each session in the series delves into critical issues at the intersection of housing, climate resilience, and environmental preservation, bringing together diverse perspectives to inspire collaboration and shared solutions.

This FAQ compiles questions raised during the learning sessions, along with others received by the Alliance from members and stakeholders. Our goal is to provide clear, thoughtful answers that deepen understanding and encourage ongoing conversation about these vital topics.

Housing Abundance and Affordability

  • As of 2024, California has nearly 15 million existing homes.  Of that number, less than 5% are subsidized, deed restricted affordable homes.  

  • California is currently building approximately 120,000 to 130,000 new homes per year. This falls significantly short of the 180,000 new homes annually needed to keep pace with population growth and household formation, as identified by the California Department of Housing and Community Development (HCD). Furthermore, to address the backlog from decades of underproduction, California would need to build 2.5 million to 3.5 million units by 2025—an average of 300,000–350,000 units annually.

  • Given current housing need and increasing construction costs across the state, it would likely cost more than $30,000,000 annually to produce enough affordable housing to meet demand.  

  • The majority of new housing in California is concentrated in suburban and exurban areas and tends to consist of market rate single-family homes. However, urban areas like San Diego that have embraced measures to make it easier to build infill housing have seen an increase in multi-family developments. Infill development is growing, but remains limited due to regulatory barriers.

  • Unfortunately, regulatory barriers in California are a persistent problem preventing housing abundance.  These include, but are not limited to:

    1. Zoning rules and land use regulations: the vast majority of residentially zoned land in California allows only single-family housing, limiting higher-density developments like apartments and townhomes.  Restrictions on density, parking requirements, and other regulations significantly drive up the cost of development.

    2. Permitting and approval timelines: Lengthy and complex approval processes increase costs and create delays.

    3. Community opposition (NIMBYism): Local opposition to higher-density projects often leads to downscaling or canceling of projects.

    4. High construction costs: Labor, materials, and regulatory compliance costs in California are among the highest in the nation.

    5. Fees: excessive impact fees on everything from parks to sewers often add tens of thousands of dollars in costs to projects per unit

    6. Environmental review: while important for sustainability, the California Environmental Quality Act (CEQA) review process is sometimes used as a tool to delay or block projects.

Development Patterns and Habitat Impacts

  • From 2001 to 2011, California has lost over 800 square miles of land due to urban sprawl, the highest amount of land lost compared to any other state over this time period. Some of the worst affected counties include San Mateo, Contra Costa, Alameda, Solano, Sacramento, and many others.

  • Urban sprawl causes habitat fragmentation, which is the leading cause of biodiversity loss as it limits wildlife movement between areas to find food, habitat, and mates. A diverse and contiguous ecosystem is more resilient and productive, ensuring healthy functioning.

  • California’s lands and waters provide essential services for human health and well-being, economic vitality, climate mitigation, and resilience. Namely, natural lands store and sequester carbon, sequester air pollution, reduce flood risk, and maintain water quality.

  • According to a pilot study conducted by the Nature Conservancy in Merced County, an integrated approach which protects natural and working lands and incentivizes development in existing urbanized areas resulted in the following relative to other approaches:

    • Less total natural lands converted

    • Less groundwater recharge lost

    • Less conversion in floodplains  

    • Less household income was needed to afford a home

    • Less vehicle miles travelled per household

    • Less passenger vehicle costs per households

    • Greatest diversity in housing types

  • An umbrella species, like many predators (with large habitat ranges and relatively small populations), help indicate to us the capacity for many other species to exist in a place. If our large carnivores in a habitat are doing well, it is a fairly decent proxy to know that the rest of the ecosystem is doing well too.

  • The Nature Conservancy developed user-friendly tools to integrate critical conservation data for advocates, policymakers, and city planners. By incorporating conservation indicators into the UrbanFootprint and UrbanSim tools, they enabled a comprehensive evaluation of development growth scenarios. These tools were utilized in Plan Bay Area, where they assessed the impacts of various growth scenarios on habitat, water resources, carbon mitigation, and agriculture. Greenbelt Alliance played a key role in rallying support, securing endorsements from 17 organizations and agencies for the scenario results. This collective effort advanced the preferred growth scenario, promoting the protection of natural and working lands.