In the twenty-first century, with new materials and technology, we have a fantastic opportunity to design buildings which respond to our needs and to those of the environment. Building skins can respond to solar radiation and temperature changes outside. Photovoltaic surfaces can draw energy from the sun. Smart materials can reduce heat loss and redirect light. Passive ventilation systems can improve comfort and reduce energy requirements. Structures can adjust to and compensate for wind forces. Lessons can be learned from nature and parallel technologies.