I have a room in my house that is above the garage, it's approximately 350sq ft, it's the only 2nd floor room, no door just stairs leading to it. I don't think the floor is insulated at all, it has it's own thermostat just for that room and I keep it at 74 degrees (same as rest of house), however most of the day it is at 76 or so and trying to cool down. I'm in Florida and once when the central air units stopped working, this room was up to 100 degrees in a matter of hours while the rest of the house was in the 80s.
I'm wondering if this room is the reason why my electric bill is at least twice what I think it should be compared to similar size homes I've lived in. It's a brand new house, everything is energy efficient. Could this room be sucking all the cool air from the rest of the house causing everything to work overtime?
I'm renting and was wondering what if anything I could bring to the landlords attention about this or perhaps do myself.