We have taken our new house down to the studs and I'm working on designing the fireplace wall. The entire room wall is 12.5 feet wide, and we are looking at a linear fireplace that is 14" high and 50" long (we want the low fireplace so we can keep the TV relatively low above it). My question is, how wide should the fireplace surround be? We plan on taking the tile or stone all the way to the ceiling. There will be shelving/cabinets on each side. Are there any design rules for proportions for the fireplace wall, or how much surround material should be on the sides of the fireplace?