I completely understand about getting them out of the house. But send them out for a couple of hours, and a little longer the next day, then leave them out. Mine are started in the garage, and outside by 3 weeks.
I have mine without electricity, but they are in a heavily bedded box with an insulated top, maybe 3 inch gap in between. Go down there at dark, and stick them in there, and they will be back there the next night. If you put a thermometer in there it will be WARM.
This allows chicks to move in deeper to warm up, and move out if getting too warm. Like being under a broody. What a broody really does, is not so much add heat to chicks, but catches their heat and holds it around them.
Mrs K