The microscopic distance of the attic vent, insulation spacing, the smoke detectors not being in sync when 1 rings etc. 

The heating units themselves are new high efficiency modern units and are working as as they should but the home just doesnt have enough insulation. 

The pros is it's got a great exterior with steel siding and a new roof. also has a 1200 sqft shop that is insulated.

A secure building will appeal more to potential tenants and provide peace of mind.Energy Efficiency:Ensure the property is energy-efficient with proper insulation, energy-efficient windows, and appliances.

Logs are excellent insulators, and emit a wonderful fragrance that will never go away.

Is there a better way to improve insulation.

Once I closed on the property I started to tear down the walls and notice that had no insulation, at that point I decided I going to tear  everything up. when I took the sheetrock from the ceiling, I was in shock to see that some electric work was done with duct tape. 

Insulate, add electrical, mini-split ac, and possibly plumbing, as desired, drywall, tape and paint, put built-in cab's on one side if you want, hang the tv, speakers, etc, install bi-fold/multi-fold doors on the side leading to a patio, and replace the garage door with an insulated one keeping the track and removing the motor, or install a carriage type garage door into the existing garage opening.

Follow the same guidelines and consider letting an outside company manage your property to give you a layer of insulation. 

To make a long, expensive story short, we discovered that builder failed to insulate an entire 3rd attic space and didn't seal wall cavities up in the main attic or insulate chases properly (Inspector failed too).