I would like to add insulation to poorly vented attic in a 100 yr old house. This is in Boston, so it's cold winters and hot & humid summers. Currently the only insulation in that attic is some blown-in in the floor and who knows how old & compressed it is. The heating bills in the winter for this place are terrible - when the electricians did all their magic this summer I got to see inside the exterior walls and found that there is no insulation in the exterior walls at all! But I figure that since the attic is under-insulated and easily accessed, adding insulation to the attic would be a good, cheap, quick thing to do before winter & might provide the best bang for the buck. I would like to simply put in some batt between the rafters so I could still use the floor as storage space, though laying some unfaced batt insul on the floor would probably be more efficient. The issue is that the attic is not very well ventilated. There are no soffit vents, though a ridge vent was added about 10 yrs ago & there is one small gable-end vent.
What should I do?