A modular fireplace surround assembly for a fireplace opening is formed from a plurality of surround components comprising a first set of components, having a foam core and a manufactured stone veneer shell, located at least 8 inches from the fireplace opening, and a second set of components formed of entirely noncombustible materials including manufactured stone veneer. The first set of components are adapted to receive fasteners that pass through the back member for either direct or indirect mounting to the wall. In one embodiment, the first set of components includes a mantel shelf formed of interconnected, main and top components. The second set of components also establishes a front facing formed of a plurality of modular, interchangeable blocks arranged about the top and sides of the fireplace opening.