Build a wall shield

Clearances for an uncertified stove are 36". These can be reduced by as much as 67% to 12" with proper wall shielding. 12" is the minimum clearance unless the stove manufacturer has tested and documented lower clearances with a wall shield in the manual. NFPA 211 allows the maximum clearance reduction if the shields are installed permanently and there is a 1" ventilated space behind the non-combustible shield. The shield material can be metal or other non-combustible like cement board. Drywall is not acceptable. If the cement board is to be tiled use latex-modified Thinset. The shield should have at least a 1" gap at the bottom and top so that air can freely convect behind the wall shield. It is attached to the studs in the wall with 1", non-combustible spacers. Ceramic spacer can be bought online or you can make them out of 3/8" copper pipe, or if working with cement board, you can snap off 3" wide x 36" strips of cement board, double them up and screw them to the studs to make vertical 1" furring strips to create the 1" air gap.

For more information go to this article:
https://www.hearth.com/talk/threads/wood-stove-wall-clearances-primer.147785/

Here are additional good tips for making it WETT certified if you are in Canada
http://www.wett-inspection.com/reducing-clearances/