:-new metal roof that will last a lifetime-new gutters-new covered porch-new side deck entrance made of Trex material-new large capacity water heater -new Bluetooth thermostat.

Love that you can imbed videos on stuff like how to use the lock, thermostat, tv, and anything else that may be confusing. 

I'm a part-time investor from Iowa who's made my way to Tokyo as a programmer.

. - Install two new high efficiency condensing boilers, and update windows and insulation for better heat loss performance.PROS - a) minimally invasive; b) can provide 15-30% reduction in heating costs (we are told).CONS - a)total gas expense is still paid by the landlord; b) individual units won't have individual control (except for a thermostat controlled shutoff valve for heat/water in each unit); c) AC would be available on with in wall/window units. 2) Try to individually meter each units' gas and provide each with a traditional forced air heating/cooling system.PROS: a)gas expense could be completely removed for landlord (huge)- even tankless hot water could be installed in each unit; b) each unit would have their own climate control.CONS: a) constructions costs of running new gas lines and soffiting sheet metal duct work. b) highly invasive with collateral construction costs; c) future costs of maintenance on multiple systems vs a single building-wide system. 3) An electric based heating system- This is tricky in my mind because of the high cost of electric heat.

IG: @MattPriestJr I have properties that I rent by the room in King/Pierce/Snohomish Counties.Many pro tips.For heating, I use Nest Thermostat and "lock" the temperature on 68 degrees. 

I do it all the time to houses that have never had central HVAC and don't have any duct work.You can control the temp in the house from one location and even add a programmable Wi-Fi thermostat for remote monitoring and control.You won't be cutting holes in the side of the house and making it look like a hotel instead of a nice house.This will increase your resale value over the other options.Mini splits and window AC units look ghetto to me, so I spend the money to do it correctly.

Ended up being the blower motor & thermostat.  

You should probably replace your thermostat with landlord thermostat (https://www.landlordthermostats.com/).

I'm also a programmer and techie so I'm always building some software or service to make real estate investors, landlords, tenants have a better experience and a more profitable one.Thanks everyone for making this awesome community, hope to be able to contribute!

The other risk I see is if there are layoffs of the middle-management ranks or high tech programmer/analyst type jobs move offshore.As you move down the price ranges and even on the higher end price ranges, if they are priced right, they get sold, get sold pretty quickly, and still getting multiple offers.