Shared Fuel in Duplex

[Erin Walt]

I have a property that I am considering converting to and getting rezoned as a duplex. The house has radiator heating, and this of course would not be split amongst the two units. The thermostat is firmly located in the living space of one unit, which means the second unit would not have control of or access to their heat source. I suspect this would be a problem - how have others handled it? I see many duplexes with shared fuel. Is there a thermostat that could have a main hub, but then a secondary sensor/control that is perhaps wireless and could be put in the second unit? I've tried searching for such a product with no luck. Thoughts? Recommendations?