One of the basic features of live/work is its open, so-called "common atmosphere" between living and working portions. This of course flies in the face of the basic building code requirement for occupancy separations -- usually fire rated -- between residential and commercial space. Many cities have chosen to mitigate this omission through requirements that the building be equipped with an automatic fire extinguishing (i.e. sprinkler) system.

Berkeley, for example, requires that all live/work buildings over two units be sprinklered. There are different types of sprinkler system installations. While fire protection engineers devote their entire careers to these different types, suffice it to say that that most common type, NFPA-13 is the most expensive to install, and that some jurisdictions will permit residential, or 13-R systems to be installed in live/work, lower hazard work activity projects, sometimes in combination with strict limitations on work activities.

Oakland’s attitude is simpler. Levels of hazardous materials and processes are limited in all live/work spaces, and residential requirements for sprinklers are imposed. These simply require that any building which contains over 16 live/work units or is three stories (remembering that a mezzanine or loft is not a story) or more must be equipped with an automatic fire extinguishing system. Additionally, these same requirements apply to automatic fire alarm system, i.e. over 15 units or two stories triggers their installation.