Over time the design of fireplaces has changed from one of necessity to one of visual interest. Early ones were more fire pits than modern fireplaces. They were used for warmth on cold days and nights, as well as for cooking. They also served as a gathering place within the home. These fire pits were usually centered within a room, allowing more people to gather around it.

Many flaws were found in early fireplace designs. Along with the industrial revolution came large scale housing developments, obviating a standardization of fireplaces. The most renowned fireplace designers of this time were the Adam Brothers. They perfected a style of fireplace design that was used for generations. It was smaller, more brightly lit, with an emphasis on the quality of the materials used in their construction, instead of their size.

By the 1800s most new fireplaces were made up of two parts, the surround and the insert. The surround consisted of the mantlepiece and sides supports, usually in wood, marble or granite. The insert was where the fire burned, and was constructed of cast iron often backed with decorative tiles. As well as providing heat, the fireplaces of the Victorian era were thought to add a cozy ambiance to homes

Some fireplace units incorporate a blower which transfers more of the fireplace’s heat to the air via convection, resulting in a more evenly heated space and a lower heating load. Fireplace efficiency can also be increased with the use of a fireback, a piece of metal that sits behind the fire and reflects heat back into the room. Firebacks are traditionally made from cast iron, but are also made from stainless steel.

Most older fireplaces have an efficiency rating near zero of less (negative effect that actually cools indoor home temperature) . Standard , modern, wood-burning masonry fireplaces. have an efficiency rating of as high as 15% . To improve efficiency , fireplaces can be modified by inserting special heavy fireboxes designed to burn much cleaner and can reach efficiencies as high as 80 % . These modified fireplaces are often equipped with a large fire window, enabling an efficient heating process in two phases. During the first phase the initial heat is provided through a large glass window while the fire is burning. During this time the structure, built of refractory bricks, absorbs the heat. This heat is then evenly radiated for many hours during the second phase. Masonry fireplaces without a glass fire window only provide heat radiated from its surface. Depending on outside temperatures 1 to 2 daily firings are sufficient to ensure a constant room temperature.