Law and tax guides

Plain-language guides to the state laws Peninsula and South Bay owners ask about most. Each one cites its sources and the date it was checked.

• SB 9 lot splits and duplexesHow California's SB 9 lets owners build two homes on a single-family lot or split it into two lots, who qualifies, and what limits it.
• ADU law updatesCalifornia accessory dwelling unit (ADU) and junior ADU rules as of 2026, including what changed on January 1, 2026, and when an ADU can be sold separately.
• Prop 19 property tax transfersHow California's Prop 19 lets homeowners 55 or older, severely disabled homeowners, and disaster victims keep their property tax base when they move, and how it changed inherited homes.
• Property tax when you buyHow Prop 13 sets property tax on a California home you buy, what the supplemental tax bill is, and how the homeowners' exemption works.
• Prop 13 and reassessment when you remodelWhat triggers a new property tax assessment in California, what does not, and how an addition or ADU adds only its own value.
• Taxes when you sellThe taxes and withholding that come up when you sell a California home: transfer tax, the federal capital gains exclusion, and California's 3 1/3% withholding.
• FIRPTA when a seller is not a US tax residentHow federal FIRPTA withholding takes up to 15% of the sale price when a foreign person sells US real estate, the exceptions, how to get money back, and California's own withholding.
• Seller disclosure updatesWhat California home sellers must disclose, including the 2026 rules on smoking and vaping history and on digitally altered listing photos.
• Buying a new or remodeled homeWhat to check before you buy a new, remodeled, or flipped home in California: permits, the certificate of occupancy, warranties, unpermitted space, and solar.

Checked October 21, 2026. General information, not legal or tax advice.