2 story, 3200 sq ft detached house. Doing our job for the environment. Inspection showed insulation varied from about 8" to 0, especially low in the front of the house, front bedrooms were always cold. NDS topped us up to 20" (R60 current standard). The technicians were very polite and professional and we continued our activities while they were here. They showed us before and after video and pictures, it's easy to see why it already made such a difference in the house. Walking upstairs used to be noticeably cooler, not any more. We have noticed too that even in this cold the furnace is running much less, one of the best investments an owner of an older home could make.