The Building code Secion 4603 has some odd rules on even and odd numbers. Generally it expects even numbers on the right and odd numbers on the left from the point where the street begins.(Market, Mission, Larkin etc all work this way.) Then it says "except on all streets having a northerly and southerly course , and lying west of Central Avenue and Presidio Avenue but not including Central Avenue." These streets will have odd numbers on the right and even numbers on the left. For example the numbered Avenues in the Richmond and Sunset follow this convention. Anyone know why this numbering system was adopted?

-- kurt Iversen (iversenk@aol.com), March 02, 1999

Answers

Basically, all street numbers BEGIN at Market Street, or the waterfront. In most cases, the even numbers will be on the right side of the street, as you work your way up in numbers, except the Sunset, Richmond, and parts of the Haight, plus probably some other areas that I'm unaware of. As far as reasoning, I have to admit that I don't know, but I will do some research to see what I can find.

-- Robert Summers (summerstime@yahoo.com), March 29, 1999.