By the way, do you avoid two-pipe systems because the temperature has to be either hot or cold in the building?

My electricity use this week didn't drastically increase, even with hotter temperatures.

They come in Soft/Warm White, Bright/Cool White, Natural/Daylight color temperatures.

Many of them do allow a temperature adjustment on the hot side, you would need to remove the triim plate and there is most likely a mechanical stop of some kind behind that. 

I'm in Vegas, and I have to deal with tenants who don't understand that you have to inch down your temperature on the A/C or you are going to kill the unit.  

San Diego, 1.3mln people, 60-70 F average temperature, one of the biggest cities in USA. 

The most significant issue noted is a requirement that "...heating facilities capable of maintaining a room temperature of 70 degrees..." be provided.  

The baseboard can be programmed to take advantage of off-peak electrical rates:  it heats the thermal mass using off peak energy, this mass then gives off heat (with some small electrical intervention to maintain temperature) during the peak hours to maintain a consistent heat in the room.Finally, if the layout of the property is fairly open, you could consider a ductless heat pump - while maintaining the baseboards for auxiliary heat.

Ok, so any suggestions on how best to solve these issues:This property is a triplex (maybe quad with an efficiency), converted from a SFR, so it's got one hot water heater for the whole building, and one temperature control (hot water / steam radiant heating) for the whole building located in the second unit.I'm thinking the cheapest way to provide enough hot water to the whole building is to replace the hot water heater with a 200 first hour rating hot water heater so I don't have to mess with the plumbing too much.For the heat, I don't know if it's easy enough to separate the heat out to each unit, if not, my thought was to just leave the temp at say 62, and not give them access to the temp control, and let them get space heaters to make up the difference.

Does anyone have any creative ideas to control the temperature on my rental homes?