Two and Sometimes 3 Houses on a Lot, Back to Back! (LA County)

[Account Closed]

few hours ago i did some drive-bys for some buyers to scope out if these properties might work for them.

back in nyc, rarely ever come across a residential lot with more than 1 freestanding dwelling on it. heck, in brooklyn, and manhattan, most are rowhouses anyways.

but here (long beach, lakewood, san pedro, and sometimes signal hill at least) it seems almost normal for properties to have a 'front house' and a 'back house' and sometimes 3. when i first moved here several months ago, alot of times when i had food delivery the courier would call to tell me they are minutes away and ask if its the front house or back house, as if customary.

how customary is it? how legal is it? ie, a lot in R-2 zoning with 3 single family dwellings on it, how did that happen; is it grandfathered or something? and how/where do i check to see how many dwellings it is ie SFH or duplex or triplex?