Insulation used when your 2x6 was built was no where as efficient as todays stuff.
Really? Has in-wall fiberglass insulation technology really gotten that much better in 15-16 years?
Oh, wait... no, it hasn't. The stuff I've bought for this house since I've owned it isn't as efficient as what's in the garage. Also, remember: R value is totally dependent on the thickness of the insulator, regardless of what type of insulation you use. Celotex has a great R value for its thickness, but I can tell you (since my house is covered in it) that you get some ice-fuckin'-cold walls where the thicker, between-stud insulation has settled (blown-in).
I have an old house. Wall construction, from outside air to inside, is: vinyl siding, Celotex, 3/4" cedar siding, 2x4 walls, and in one room drywall, two others plaster and lath, and in my bedroom I have the insulation I've bought after tearing down the paneling and losing the blown-in insulation. With two extreme air leaks to the roof vents, my bedroom is still the coziest room in the house. One outside wall of my living room is not only lath, but LDF stuck to the plaster while it was still wet. :doh: That's the
coldest room! The blown insulation has settled, and with an infrared temp gun I've seen differences of almost 20° on that wall from the base to the ceiling.
You simply cannot buy insulation with the R-value of what fits into a 2x6 wall to work in one 2" thinner, without spending more than the 2x6 walls would've cost in the first place. If you squeeze the thicker insulation down, you're right back to what would have cost you less, because air's a prett-good insulator, and most insulation depends on it for its effectiveness. Check out the R value for concrete... pretty crappy.
I'm not bashing on Dip; he did a damned-fine job on this whole project and it's obviously working well. For that, I'm happy because he obviously is... and if he took offense to my comment, I apologize. I would be honored to spend some time working in his shop, regardless of time of year.
Nor am I making the balls big: I bought my garage as-is; it was already done. If I'd had to build one, chances are it wouldn't be as nice as Dippy's. I'll bet his house is much larger and nicer than mine, too!