Where the water goes is the regulated part
Gutters themselves are rarely regulated; discharge can be, through city stormwater expectations. On the dense lots typical here, the practical constraint is often the neighbor rather than the code — concentrated runoff crossing a property line causes problems no gutter specification solves. Coastal wind also means hanger spacing and fastening matter more than trough gauge.
Official sources
Settle the discharge point before installation
Citywide guidance will not tell you where your runoff currently goes, how much roof drains to each outlet, or whether the fascia will hold new hangers. Settle routing before anything is ordered.
Research date
Sources reviewed June 22, 2026. External requirements and maps can change.