San Francisco requires most new developments to include below-market-rate units — and if you know how the lottery system works, it could open doors most buyers don't even know exist. Here's what every SF buyer needs to understand before entering the market.

SF is expensive — but the city quietly puts on some genuinely great free events every single month. A block party with the biggest disco ball west of the Mississippi, free admission at the de Young, adults-only nights at the Academy of Sciences, and free zoo days for residents. Here's the cheat sheet.