Question: We're about to start building a stackwall home in Eastern Ontario (just north of New York state). While the home will be well insulated- with an efficient woodstove for heat- we really want a stone fireplace. My question(s) are: - is there any way to keep the fireplace from allowing tons of heat to escape when it's not being used? Answer: Glass Doors- and outside air inlet help greatly- so does building the Fireplace structure inside the home. - is that what fireplace inserts are about- and how effective are they? They are very effective. If you are building from scratch, check out some of the high efficiency built-in wood burning models currently on the market.