Drafts were a major problem in this house when the fireplace was front and center in the living room. It let in warm and humidity in the summer and kept the room very chilly in winter. Last summer I bought a large (est. 4' x 10') pink styrofoam-type plank of insulation and measured and I cut pieces to build a box that fits into the cavity - it doesn't just cover the front, it is literally a box I slid into the fireplace cavity, starting with lining the sides, the back, (two pieces because it slopes), the bottom, and then a facing piece on the front that is flush with the stonework on the fireplace wall. I caulked it with low-pressure window sealant foam. I put a plank on the rock hearth (not level) and with shims made the 3/4" plywood piece level, and the large television sits on that, blocking the pink portion of the rock wall. It feels so much better in here. If I get insulating curtains for the sliding glass door and the double windows on the back of the house (same wall as fireplace) I'll have an even better insulation system. My electric bill went way down.

I finished a couple of deadlines over the break, but more of them loom. Must trot!

SRS