Whether you choose a gas insert or wood insert, you’ll get a fireplace that performs just as efficiently as you do. Remodeling or renovating your current fireplace is a great way to breathe new life into a space while increasing your home’s heating efficiency. If you have an existing masonry fireplace opening - think stone, brick, wood, matches, etc. - then a remodel using a fireplace insert would be ideal. Gas and Wood-Heating Fireplace Inserts are completely sealed units that are inserted into an existing opening and vented out using the chimney.