Mini splits are finicky and you could need multiple heads (equivalent to thermostats) to create separate cooling zones, plus many are not rated for very cold outside temps like you get in Ohio winters.

Major items in the renovation include:Level floors, Lay new peel and stick vinyl throughoutRemove wall heater from bedroomRe-sheetrock in living room to smooth out wall (tie control thermostat wires in wall to provide power on roof)Install new plumbing runs throughoutInstall new drain lines where applicableInstall water line and in-wall box for refrigerator ice makerInstall new tubInstall new tile shower surroundMove over all light switches away from door trimRun wire to two new living room lights, install three way switch outside of bedroom and exterior patio doorInstall new light and wall switch in bedroom closetMove bedroom door 6-7 inches to the south to allow construction of half wallDemo existing living room closet and construct half wall (replumb gas and electrical as required)Demo kitchen cabinets, pantry and counterInstall sheet-rock over water damaged hardboard in bathroom and bedroomsInterior Paint throughoutInstall new bathroom vanityInstall new bathroom lightInstall new kitchen lightInstall new cabinetsInstall new granite counter topsInstall new AC registers (bedroom and bathroom)Install new toiletInstall three (3) new six-panel doors (bedroom, closet, bathroom)Install new outlets and coversInstall new switches and coversAgain, my four estimates for this work range from $14,000 to 25,000 and would complete in 2-3 weeks.

Currently, I have 2, 22-year-old high-efficiency furnaces that are controlled by 1 thermostat (I pay for the heat) and window units for AC which the tenants pay. 

Smart thermostats and doorbells can give the place a higher end feel. 

Thermostat: install a wireless thermostat and move the sensor to the living room?

@Paul Mendel part of the problem is that we have one thermostat for the entire building.

Updated the shower, new toilets, new electrical outlets, garbage disposal, smart thermostat.

State of the art video monitoring alarm system w/ remote access garage, thermostat and lights.

When looking at everything from garage door openers to water heaters to thermostats, it all seems to come with a "smart" feature.

What is your thermostat setting in the summer and winter?