CA AB1537

Classifies counties in the San Francisco-Oakland-Fremont MSA with populations under 400,000 as suburban (rather than metropolitan) for housing density requirements through December 31, 2023, allowing lower density thresholds of 20 units per acre instead of 30.

Requires incorporated cities with populations under 100,000 within qualifying counties to also be classified as suburban for the same period.

Mandates affected counties utilize existing housing trust fund balances as of June 30, 2013, for development and preservation of low- and very low-income housing.

Requires affected jurisdictions to submit progress reports to the Legislature and Department of Housing and Community Development on two occasions: by December 31, 2019 (covering initial four years) and December 31, 2023 (covering remaining cycle).

Applies housing density requirements in effect on June 30, 2014, within one-half mile of Sonoma-Marin Area Rail Transit stations; all provisions expire December 31, 2023, unless extended by subsequent legislation.