I purchased an old house (built in 1945) that had very little insulation in the attic and none in the basement. I was fortunate to qualify for the energy audit under the full program so a year after I moved in I had arranged for Great Northern Insulation to come out for an estimate.
I had estimates from 3 other companies but the representative from GNI was the most knowledgeable and helpful plus their price was very competitive.
They arrived on time and I was pleased with how quickly the job went. They increased the insulation in the attic from its original R20 value to R50 and did a great job of cleaning up the mess. At the same time, another crew was in the basement putting spray foam insulation in the headers and on the walls. Again they did a great job of cleaning up afterwards.
I would not hesitate to recommend them to anyone looking to add some warmth to their home. It has made a huge difference in my heating costs and it is so much cooler in the house in the summer.