I think that you should have public liability insurance if for no other reason than if the machine becomes faulty and injures someone you could be liable. Also what if a resident missuses or breaks it?. Either have the proper insurance or make sure the residents of each bungalow has adequate insurance themselves.
What about the old codger who thinks he or she is still fit enough to do a proper job but maifestly isn't capable? Whose fault is it if they cut their foot off or pulls a shoulder out of joint?
However if the local authority already cut it you may have to check with them as it may be againsts the dreaded H&S rules for you to do it.