Yesterdays inspection. In the garage was a forced air furnace and gas water heater mounted on the wall in the garage. They sat in individual steel welded holders. Angle iron on the back of them with drilled holes and bolts into the studs of the wall separating the attached garage and house. The base (bottom) was at appx 4 ft. Making the tops 10 plus ft. Water heater cold shut off valve appx 12 ft high. Bottom of forced air furnace not able to have return at that point (so no filter) Hole cut out on back of unit for return air from duct penetrating firewall (not sure of gauge of ducting) insulated. Permits,TPR discharge aside. Comments on this application please: ie weight being carried by studs, height for service replacement etc. Return air back of furnace. First time seeing this.