It's chilly in there

Been noticing the family room has been chilly of late (since the temperatures outside started to drop). For a while, I thought it was just the door, window, and lack of insulation on the walls. But last night, as I was sanding and patching some of the drywall, I discovered it's not so much what's coming in, but what's coming up.

Below the family room is only a crawlspace. And the floorboards don't seal up to the walls/sills completely, and we've got those holes from the old plumbing that came up out of the floor when it was a kitchen. And there's plenty of cold coming from there. Fortunately, we'll have the walls finished, new floor in, and some baseboards in place to block the air. And come summer, I'll crawl in there and put some fiberglass batting between the joists to tighten things up some more. In addition to the expanding foam I've been trying to put into that gap on the far edge.

It probably won't make a large difference as far as heating costs, but should hopefully deaden the sound some as we're walking around, and keep the floor feeling slightly warmer.