Abstract: A method and system for conversion of a fireplace to an updated or different model or configuration is provided. For example, such conversion can apply to any fireplace configuration, indoor and outdoor, commercial and residential, to provide a different fireplace appearance. A converted fireplace comprises an existing firebox, an existing exhaust system, a shell and replacement firebox, and an exhaust adapter. The firebox and exhaust system typically comprise the existing structure within a residential or commercial fireplace installation. The firebox can he of various heights, widths and depths, and yet still be converted, while the exhaust system can comprise various configurations, such as B-vent, direct vent and the like, and yet coupled to the replacement fireplace unit.