ADUs Now 28% Of Bay Area Permits
California's housing market is entering August on two very different tracks. Backyard housing has quietly become one of the state's most dependable sources of new supply, with accessory dwelling units now accounting for roughly a quarter of newly permitted homes statewide and nearly 28% of approvals in the Bay Area — a shift that hands homeowners and small investors a rental-income lever that doesn't require buying another property. On the transaction side, momentum has cooled. Thirty-year mortgage rates pushed to a one-year high in late July, pending sales slipped to their lowest level since spring, and the market is splitting between well-bid luxury listings and starter homes that sit.
In The News:
Planetizen — ADUs account for nearly 28% of Bay Area housing permits (July 27, 2026) — A San Francisco Chronicle analysis of permit data reported to the state found ADUs made up just 8% of newly permitted Bay Area homes in 2019 and 18% by 2025. When multifamily approvals slumped in 2024, ADUs took a record share of nearly 28%. The region has permitted a steady 1,100 to 1,400 ADUs a year since 2021 while larger projects swung sharply up and down.
Davis Vanguard — California's Housing Laws Are Beginning to Work — But the ADU Boom Reveals the Next Challenge (July 27, 2026) — Statewide, ADUs made up roughly 26% of all newly permitted homes last year, and in affluent enclaves they are nearly the entire pipeline — Hillsborough permitted 58 units, 56 of them ADUs. The catch for owners counting on yield is occupancy: an earlier UC Berkeley survey found only about half of ADU owners actually rent the unit to a tenant.
Freddie Mac — Mortgage Rates Average 6.66% (July 30, 2026) — The 30-year fixed averaged 6.66% for the week, up from 6.58% and the highest reading since August 2025, while the 15-year averaged 6.04%. Chief Economist Sam Khater pointed to more available inventory giving buyers additional options and supporting activity even as rates move around. A year ago the 30-year sat at 6.72%, so borrowing costs are roughly flat year over year.
Redfin — Redfin Reports Homebuying Demand Slows As Mortgage Rates Hit Highest Level in a Year (July 30, 2026) — Pending U.S. home sales fell to their lowest level since early April during the four weeks ending July 26, dropping 1.7% in the final week alone. Redfin tied the pullback to daily average mortgage rates reaching 6.85%, a one-year high. Buyers are hesitating rather than disappearing, and correctly priced listings are still going under contract.
Zillow — The housing market is splitting in two: Luxury homes are in high demand while starter homes sit (July 29, 2026) — Luxury sales rose 6.2% year over year in May while luxury inventory fell 5.2%, producing tighter supply and more bidding wars at the top of the market. Starter-home sales dropped 5.4% over the same stretch, with inventory up 4.5% year over year in June alongside longer days on market and more price cuts — leverage for investors shopping the entry-level tier.
