Insulating the blocks The voids in concrete blocks can be filled with a variety of inert materials, such as vermiculite and polystyrene. However, research has shown that the majority of heat transfer is through the solid parts of the block, so there's little energy saving, according to the US Department of Energy. So there's a better return on your insulating buck by doing the interior insulation efficiently. Flash and batt Simply put, first comes sprayed foam, then, usually fibre glass. Done properly, it works well at a cost less than doing all foam, but more than using fg. See Martin Holladay's comments in the linked forum below. Here is a link that might be useful: Spray foam and batt insulation.

hire an energy rater to give you specific to your home info. what my years of this type of work have taught me is that the air sealing is the first line of defense. a blower door test will show you where your house leaks and a duct test will show where ducts leak. in new construction nationwide there is 25 to 30% duct leakage in new homes..in existing homes it can be higher..it can also be lower..but not often the case. caulk..not great stuff will provide a good flexible seal that will last (depending on years of caulk purchased) great stuff breaks down and does not expand and contract. if you can stop the air leakage into your house it will be affordable to heat and cool once the air barrier is complete then insulate. insulation slows air movement but doesn't stop it (except foam insulation which when properly applied lowers air infiltration..for a price) when air moves through insulation it lowers the performance of the insulation. when you put a power attic ventilator it pulls air from inside the house (at air leakage sites) and from ductwork located in attic (duct leakage sites). pav's can put the house under a negative pressure causing the house to pull in air via holes ..recessed cans..the oversized cut for the drain under the tub...many of these leakage sites allow voc's into the house which contribute to allergies ect. cellulose insulation has a fine powder that spreads through out the house..entering through leakage sites and spreading via hvac system. caulk caulk and caulk. your biggest payback is reducing the air infiltration. after that the duct/return air leakage then would come insulating attic..biggest savings crawlspace..open cell foam not batts. batts droop over time due to gravity..and condensation forms on the undersides of floors causing floors to rot. as wind sweeps the batts it robs the insulation of R-value (you should see a thermal scan of batt insulation in floors on a windy day!) then lastly walls. air seal walls prior to insulating caulk ceiling moldings to ceiling and wall floor moldings to wall & floor window and door frames to walls gaskets behind plates of switches and outlets. There is a national association of energy raters hire one to evaluate your home and give you real world proven information for your home. www.natresnet.org we are trained, nationally certified unbiased professionals. best of luck

I'm in the northeast with a house that has the same combination of cathedral ceiling and attic spaces. Our problems are probably yours times 100. I agonized for a year over how to re-roof and insulate, and ended up going with the smartest roofer I interviewed who said, basically, you are far better off spending money on circulating air with fans than in trying to improve the insulation in the roof. I don't know if this is at all relevant to your situation, but at least it should make you feel better. I mean, how bad can your temperature shifts be in Hawaii??

... you either have to insulate the ducts and the ceiling (if the basement or crawl space are not conditioned) or you would have to insulate the basement or crawlspace walls and floor and condition the whole space. I thought that's how it worked here, too. Is the contractor done? Have you mentioned this lack of insulation to the contractor? Yes, they are done working, BUT I WANT TO CONTACT THEM ABOUT THIS ASAP, since I just noticed the lack of insulation. I wanted to be sure I was understanding the "snap-lock" was the rigid duct stated in the contract, before I contact the HVAC company. I was also hoping someone would confirm that if the rigid duct were insulated, that it would be visible or printed somewhere on the product, as other insulated items are.