Thanks bungeeii. I actually made contact with a spray company that had a certified Energystar auditor working with them. They did an energy audit today and took measurements to estimate the job. They estimated the following rebates, and will put these terms in the contract as stipulations before any work is done: 1. audit costs $400 with $125 rebated if the work is done. 2. $1000 govt rebate off the top for a thin barrier spray in the attic floor. I don't have the exact terminology in front of me, but it is basically a skim coat of foam onto which is blown cellulose or other for attic insulation. 3. up to 50% rebate ($5000 max) depending on the results of the energy audit. Because I have high efficiency furnaces and on-demand hot water, she says that I will rate at a 25%+ energy savings, which will put me at the 50% rebate from the govt. The rebate takes about 10 weeks. So, in their example, if the job costs $11,000, I pay $10,000 plus the $400 for the audit ($1000 "instant" rebate for the attic thing), then get $5000 + $125 back in 10 weeks. After my contractor subtracts out what he was charging me for fiberglass, I should net out at a very reasonable number. The people today were my third estimate, and I believe they were the most knowledgeable about the right thing to do. I'm just waiting till next week for their estimate. Thanks again, I think I'm finally getting the right game plan together!

Mongcot Thanks for replying. I don't think you screwed up the math but the main difference is that I decided not to go so thick. The contractor said he would spray in r-38 in the ceiling. ?From what I understand that would be overkill. I had no option if I went with him other than to go with that much spray foam, He didnt want to do the job unless it was $6k+. No other contractors in my area . The contractor also would not take doors and windows out of the EQ. I have 6ft sliding glass doors and large windows. I spent $3k will do approx. 3" on the underside of the ceiling, 2" in walls and under floor. That cost also included the fast kick gun. I have 2 large emglo air compressors already sitting in tandem. I read that 4" of lycene foam was used in making freezers , If that's true I figure I should be ok. Am I right in thinking that I don't need "R-38"(6" or so)? So my options were $8k for what sounds like overkill(wish I could have used half as much for $4k ad had someone else do it but he wouldn't budge. or batt insulation for half that much . The pallet arrived late with the gun missing . A new gun was supposed to be here last friday. its tuesday no idea when the gun will arrive so I am sitting here ready with a pallet of foam. This looks like a lot of work and want to get the drywall up . but hopefully it'll be done with no major setbacks in teh next couple weeks

I'm glad to come across this thread because I'm also trying to figure out whether/how to add blown-in insulation to our attic, and possibly radiant foil. I hope I'm not derailing the thread by tacking on. Our home is a roughly 120 year old Victorian, and it also has a sprinkling of old insulation in the (sealed) attic, but nothing more. And when I say attic, I should clarify--we actually have a finished attic/third floor but the very peak of the attic, above the ceiling of the finished area, is unfinished. It's like a capital A, where the lower half is the finished portion and the upper half is unfinished. I'm sure there's proper terminology for that but I don't know what it's correctly called. We use the finished portion regularly, or at least we would if it didn't get very hot up there in both the winter and the summer. In the winter, we can counteract this by closing the HVAC vents so the attic is only heated by the hot air rising through the house, and that works well enough. But in the summer, we add two window units in addition to the house AC (to cool a space that's probably 400 sqft)--the window units are kind of a mixed bag because with the way they're installed, they let in a good portion of hot outside air around them through the window. We're contemplating replacing the window units with a minisplit system in the attic alone, but I feel like it's worth exploring all the various possible ideas to try to keep summer heat out of the finished portion of the attic before installing a whole new additional system. Any thoughts or ideas for me?

Nothing about your home should keep you up at night. If concerns about using a particular construction material or method will do that, then don't use it. However, if we never applied any new materials, systems, and construction methods in residential construction, our homes would be no more comfortable and perform no better than homes built in the 1700's. We wouldn't have, for example, air conditioning, which makes living here in coastal Virginia much more pleasant in summer and which keeps certain contractors in the Houston area employed. The energy crisis in the 1970s gave rise to the use of house wraps and vapor barriers which caused plenty of unintended consequences. That doesn't make polyethylene or house wrap bad materials, it's simply that the building science wasn't established at the time. We continue to rely on the researchers to thoroughly test new ideas (and real world testing is better than computer simulations) to minimize, if not preclude, unintended consequences. When considering the use of the latest and greatest materials homeowners would be well advised to remember the old adage: The early bird gets the worm, but the second mouse gets the cheese!