The prefabricated, factorybuilt fireplace was born in the building boom of the 1970s as a solution to the high demand for fireplaces and the severe shortage of masons. These new "builders boxes" were inexpensive, quick to install, and could be handled by carpenters — no masons were needed. They did not, however, satisfy customers looking for the quality and durability of a masonry firebox. In response, manufacturers have developed new options that combine the quality of masonry with the low cost of a prefab installation. Some combine the masonry firebox with a metal chimney, making them a new breed of hybrid fireplace. Early Prefabs The original prefabricated chimneys were made of three interlocking pipes that circulated air to remove excess heat. The triple-wall chimney system
