The fireplace ready for bricking. The chimney to the right is for the (future) basement fireplace. Immediately above the two chimnies, in the attic area, is a box surrounding the chimnies to separate them from the cellulose insulation to be blown into the attic. Most people leave the box around these flues empty because combustible material is not allowed within 1" of them by code, but I chose to fill them with vermiculite (a fully oxidized mineral product) because it has insulating value. The R value around the pipes is about R-60 minimum.