Legal Question in Real Estate Law in California

Re: Zero Lot Line law Modesto, CA

I suspect this was done without permits, but maybe they weren't required. Some small garden and storage sheds don't require permits. That's one of the first things a lawyer would need to know.

The next question is whether zero-lot-line construction is common and permissible in your neighborhood.

In many communities where zero lot line construction is the norm, it is pretty well understood that the privilege of building right up to the neighbor's property carries with it a commensurate burden of allowing the neighbor to enter your property for maintenance of the exposed parts of his building (roof, gutters, upper portion of walls, etc.). The right is a kind of easement.

Here, your neighbor seems to have handed you a worse situation than the usual zero-lot-line party wall, in that you get neither protection from complete closure of the void spece between buildings, nor enough space to get in to paint, remove trash, check for rats and wasps, and so on.

I think you could approach this either as an un-permitted structure (if it is and they were required) or as a private nuisance, and demand its removal or moving so you can do maintenance. As usual between neighbors, I advise trying to negotiate a solution before filing suit or making a complaint to the permits department.