I thought this is an interesting enough problem with enough universal appeal that I had a Taiwan lawyer colleague look up some more on this issue. Here's what he's come back with:
1. Authority in Charge: The name of the agency in charge of the issue varies in different city or county, such as the "Building Administration Office" in Taipei City and the "Public Works Bureau, House Use Management Section" in Taipei County, but all of them are related to building administration instead of fire department. Note that the fire department will do annual checks for certain buildings or community and will focus more on fire prevention related matters. For cases involving facilities safety, they will only transfer the case to one of the aforementioned building administration agencies, which will send its staff to check and give a notice or even a fine for people violating the laws.
2. The way to report the matter: the various government departments have combined their reporting system, so no matter where he or she is, just simply call 1999 to report the matter. The government will pass the report to the official in charge for action.
Now, one might dance a bit around the idea of one's relationships with the neighbors, but in the end the only way to get them to change their behavior will likely be the threat of a fine.









