Pueblo style architecture seeks to imitate the appearance of traditional adobe construction, though more modern materials such as brick or concrete are often substituted. If adobe is not used, rounded corners, irregular parapets, and thick, battered walls are used to simulate it. Walls are usually stuccoed and painted in earth tones. Multistory buildings usually employ stepped massing similar to that seen at Taos Pueblo. Roofs are always flat. A common feature is the use of projecting wooden roof beams (vigas), which often serve no structural purpose.