I am constructing an ADU in San Jose, CA, and the code says "If the accessory building or structure exceeds 120 sf and is less than 5 feet from the property line, walls parallel to the property line must be built with a 1-hour fire protection."
- Do both the ADU wall and the existing property wall be built with a 1-hour fire protection?
- How much will it cost and how long will it take to upgrade an existing wall (built in 1952) to provide it with 1-hour fire protection? The wall is about 20 feet long (single story).
- Can we provide fire protection to an existing structure from the outside of the house (without having to change anything inside)?
The other option is to move the ADU wall to provide a separation of 5 feet (I'll lose about 18" from the side wall), but that requires a new foundation and new plans to be submitted. Not sure if this is a route I should explore.