my house is also pretty cold in the winter... i've put a blanket around the back and sides of the cage for some insulation. it helps some. i keep the screen top closed off a bit to keep in the humidity. glass tanks are kinda hard to keep warm as opposed to the plastic or acrylic tanks, but this is what i have so i work with it. if it's a really cold night, i have a space heater to raise the temps in the room.. my bp seems pretty happy with that setup