A fireplace insert is one of the fastest ways to upgrade an existing wood-burning fireplace: instead of rebuilding, you slide a sealed, efficient firebox into your current opening and instantly gain better heat output, cleaner combustion and easier everyday operation.
Step 1: Pick your fuel type
Gas inserts are the most popular choice. They ignite at the push of a button, produce steady heat, and vent through your existing chimney with a liner. Browse our full range of gas fireplaces and inserts, including direct vent models that seal combustion air off from your living space.
Wood inserts keep the crackle and aroma of a real fire while burning far more efficiently than an open hearth. See our wood fireplaces and inserts.
Pellet inserts burn compressed wood pellets fed automatically, offering set-and-forget heat with low emissions. Explore pellet fireplaces and inserts.
Step 2: Measure your opening
Inserts are sized to fit inside your existing firebox. Measure the width, height and depth at the front, middle and back (fireboxes taper), then choose an insert with a face that fully overlaps the opening. When in doubt, send us your measurements and our team will match you to the right model.
Step 3: Match heat output to your space
As a rule of thumb, plan for roughly 20 BTUs per square foot of living space — a 30,000 BTU insert comfortably heats a 1,000–1,500 sq ft room or open floor plan. Also consider a fan-blown unit for better heat distribution versus radiant-only models.
Step 4: Don't forget venting and finishing
Gas and pellet inserts require a stainless chimney liner and termination cap; wood inserts need a listed chimney system. Trim, surrounds and hearth pads complete the finished look — and many manufacturers offer custom surrounds to match your existing stonework.
Ready to compare? Browse all fireplace inserts or reach out for expert help choosing the right model — every order ships free.