The brands that make the smallest wall ovens include KitchenAid, Bosch, Blomberg, Dacor and Frigidaire. The smallest available wall ovens usually measure 24 inches wide.
Other brands that sell 24-inch wall ovens as of 2015 include Summit, Whirlpool, Fagor, Verona and Fulgor. They are available at Lowe's, AJ Madison, Amazon and other home-supply stores.
Small ovens come in both gas and electric models. Some brands, including Wolf, make small steam ovens. Most models feature the same controls and functions as a full-size oven. The cooking space of a small oven varies based on height and depth, but usually ranges between 1.5 and 3 cubic feet.