I assume the 5 apartments share one HVAC system? If they are separate, aren't they separately billed? If so, then the occupant is the one paying for their excessive temperatures.

While I live in my our house, if I lived in a shared dwelling, I think I'd be uneasy if the landlord effectively said, "You have your thermostat set at XX; I think it should be at YY".

While I understand why you think it's better to not waste energy, unless you have other restrictions on your units (ie. can only run a shower for 10 minutes), you might just have to accept that with freedom comes the potential for abuse.

Jeff

Jeff, this is not a hvac it is only heat, no they are not separately billed. They have thermostats that run off one furnace and I pay the bill and yes I do have a right to tell the tenant they cannot waste heat. If you look at any standard lease it is right in the lease. I also have the right to set the temperature for the apartments.
"During the heating season the landlord must supply heat and rooms must be heated to between 68ÃÂF and not more than 76ÃÂF between 7:00 a.m. to 11:00 p.m., and at least 64ÃÂF at all other hours". I don't need to worry how long they take a shower b/c they do pay for their own hot water which makes the tenant conserve naturally.
I'm looking for someone that understands the new "smart building technology"

I am just a homeowner but something comes to mind that may help.

There are thermostats that can be controlled via the www - either from a computer or, I believe, a Smart Phone.

You could set up the thermostats such that you alone have access to the thermostat remotely.

Again, I am not in the trade nor do I have such a thermostat.

Thanks Saltidawg, I will definitely look into that.