Selgas
Heck – ya could hook up a main wet system with bypasses at each apartment and control the heat on/off at each apartment with electric solenoid valves – ya could even have them wired through some kind of coin operated metering system to ensure each tennant paid for what they used.
Gas Tankless water heaters fitted to the exterior walls of multirise buildings are the common place things in vogue today – they are high output units that provide adequate hot water for two or more oulets at the same time and can be temeperature controlled for convenience. 
Selgas Services Ltd
Craftsman Gasfitters, Plumbers, Electrical Service Technicians
