There is a provision in the B365 part of the code for reducing clearances on wood stoves. This provision is called shielding. To comply, a wood stove must meet certain clearances from the closest walls. If the label says the stove needs 15” of open space behind it and distance  is only 10”, this means the stove is not compliant and should not be used. You can however shield the wall to reduce the required distance up to 66%. Here are the basic rules of shielding. A shield must be made of a material that is non–combustible such as 26 gauge or heavier steel plate or tile or stone to name only a few. Depending on the material the reduction % will change. The shield must; be supported on non-combustible spacers at least 7/8” long (away from the wall), be placed 1 – 3” off the floor, 22” above the appliance and 18” past the sides of the stove. The shield will reduce the 15” requirement to 7 ½” or 5” depending upon the shield material.