Can built-in furniture be installed near sprinkler piping?
Since there are no sprinkler heads, valves, or such involved -- there's no need to maintain any set clearance from the pipe with nonstructural, non-fire-partitioning elements, such as furniture.  (NFPA 13 has no minimum clearance requirement for sprinkler piping that I can find, save for the 9.3 requirements on clearance through firewalls, and those are both a) driven by seismic concerns and b) on the order of an inch or so.)