Wenner creates art and architectural details for the exteriors of homes using a variety of permanent materials that can withstand the elements. For sculptural elements he employs cast stone in resin and cement as well as terra cotta. Very large elements may be hollow- cast to reduce their weight. For exterior murals and painted decorations, he uses ceramic tiles fired in Italy.

Commissions for exterior art and decoration begin with a drawing. Upon approval the design is sculpted in clay, and a mold is made. For repeating architectural details, multiple are cast from the same mold. Depending on the clients taste, the pieces may be created with aged and rusticated surfaces. The textural effect of the ageing is in the mold itself, and does not compromise the strength of the piece.