Separating Heat in Walden NY 4 unit

[Louis Aller]

I have a four unit in "upstate" NY with one oil boiler paid for by me. What is the best way to separate the heating system and pass that utility onto the tenants? (The utility company will run natural gas lines to the building for free provided I hook them up to something within 60 days. 1.)Should I just throw in electric wall heat into every unit and reduce the rent to account for higher heating cost to tenants? This is the cheapest upfront option to me 2.) Should I just throw in four natural gas boilers since the radiator systems are intact? This is being quoted at 5-10k per unit. 3.) Should I just install mini ductless heat pumps that do both AC and heat? The advantage there is that I would get cooling without having to install duct work, however this is being quoted at nearly 6k per unit. 4) Or should I just keep paying the oil heating bill?