For those of you with a crawlspace, do you have insulation in your floor joists?

I’m currently having a home built and the builder asked if I wanted insulation in the crawlspace. Rather stunned, I replied with, “I thought every home got insulation.” He then explained to me that nowadays many people are skipping the crawlspace insulation because studies show that it really doesn’t help much/at all.

Apparently there are 2 sides to this. 1 being insulation helps keep the home cool in the summer and warm during the winter. 2 being the studies have found that insulation traps moisture and will begin to mildew and the insulation will start to fall down over the years anyway.

He also informed me that half the homes being built do not have insulation in the crawlspace. Just FYI, my home will have hardwood floors and will be well insulated in the walls and attic. Also, the home is in Kentucky so it’s not in a warm climate year around.