Community: Green building techniques

I am working with a local energy efficiency contractor. They are replacing my old roof (which badly needs replacing) with a new roof. They will be spraying five or so inches of closed cell foam directly against the decking. This will fully seal my attic. My question is, how does this work if you do not have air conditioning in the house, other than window units in the bedrooms and one in the living room.

I'm getting quotes from contractors right now to insulate a small cottage with an unvented cathedral ceiling using 2x10s. I'm in zone 3C.

One contractor has suggested spraying 5.5" of open-cell foam between the rafters and calling it a day. I asked if we could just fill the entire 9.5" cavity and he said, "You achieve maximum efficiency @5.5. Any more is overkill. It will expand a couple more inches as we will not cut it but leave the excess."

Code requires R-30 for ceilings around here.

I may be wrong but doesn't more insulation mean higher R-value?

We are building a new home soon and I really want to include a small cold cellar to age a few beers and keep some wine cool in lieu of a beverage refrigerator. I also want keep our chest freezer (we buy full animals to process) in here to lower its run time.

Part of my retrofit included a standing-seam metal roof, the type
with snap-together panels. I've read some of the folks' prior
experiences with metal roofs and snow, and spent some of my first
winter watching the big cornices slowly form over the edge and
then thud down -- in the back of the house, onto the basement
bulkhead and outer edge of the little matching rooflet over the
heat pump [and boy, am I glad I constructed *that* to be strong],
and shoveled most of what fell farther away from the house so it
wouldn't form a huge mound and then melt toward the basement wall