I might have mentioned that, early last month, we had insulation installed into the joist bays of the laundry room's exterior wall and on the crawlspace side of all the walls between the crawlspace and the laundry room & stairway, including under the stairs. At the same time, they filled all the through-holes between the crawlspace & laundry room and the crawlspace and main house using foam and some kind of caulk. The combination of all this stuff will not only provide insulation but also cut breezes.
I'm not sure of the R-value of all that insulation. The stuff in the exterior wall is made from recycled blue jeans and looks it; we used that because it's exposed and I don't want to cover it. The insulation on the wall to the crawlspace is pink fiberglass; I think it's R-13. They also used the blue jean insulation to seal the gap at the top of the crawlspace wall. For some reason, that wall gets up between the joists, but doesn't actually get to the sub-floor above. Don't know why, but it allows a huge amount of air in when there's a breeze outside.
We noticed a difference right away, mainly in Rachel's room, which is right above the laundry, but also in the basement in general. The real proof of it will come later in the winter when it's cold and windy, I suppose, but we got a real example of it while I was doing the basement renovation work. I left the basement window and door closed over night, and Rachel's room was essentially the same temperature as the hall outside it when we got up. When I went down and opened the door & window and turned the fan on to ventilate the laundry room, though, the temperature in her room dropped noticeably in less than an hour.
Today we had the same insulation guy come out and put R-19 fiberglass insulation under the floors of the main house except for Rachel's room. I don't want to cut the height in the laundry room, even between the joists, or I'd probably go ahead and put insulation in there. I'm also not sure that would really be worth so much, since we're doing so much insulation and we're closing off the breezes, I think the downstairs will be much warmer. Anyway, the laundry machines (when we run them - we're doing a lot fewer loads since we got them) and the water heater provide some heat in there. I'm also contemplating the notion of putting a small hole into the heating duct that goes through the laundry room so that it will actually be heated by the main house furnace. We'll see whether it seems necessary within the next couple of months.
So far, since we bought the house, we've increased the insulation (1) in the attic to R-30 with blown-in cellulose, (2) done the laundry room and crawl-space, and (3) under the floor. Still need to do the walls...