Making a one-sided fireplace two sided is possible. If you are considering this project, there are some important things to consider.
What to Consider When Making a Fireplace Two Sided
1. Is it the Right Kind?
You will generally want to make this conversion only if the fireplace is already a ventless gas fireplace or you intend to make it a ventless gas fireplace.
2. What if it’s Not?
When dealing with a vented fireplace, the flue will not be large enough to handle the double-sided fireplace. You can use a fireplace exhaust fan, but these are quite expensive.
3. Do you Have the Support You Need?
Before removing the rear of the fireplace it is important to determine if that portion of the wall is a load-bearing wall.
If the portion of the wall you will be cutting out is supporting a large portion of the chimney, then it may become structurally unsound if you remove it. This is often not a problem since many homes are not built with a true chimney.