We have an “A-frame” gas fireplace in our family room. Thinking of updating and replacing with an electric fireplace. Space footprint would be less; would energy be more efficient?
The answer is, it depends. Electric fireplaces are usually less expensive to purchase but can be very expensive to run. However, if you have an old gas burner that is mounted inside a brick fireplace, then that can also be hugely wasteful.
In general, gas or wood fireplaces are not very energy efficient because they also use up heated air inside your home as combustion air which is drawn into the fireplace and sent up the chimney.
New gas fireplaces can be reasonably efficient though so the answer really depends of balancing all these factors. You might also look into condensing gas fireplaces which are costly but amazingly efficient.