Non residential buildings such as shopping centres and hospitals must have photovoltaic panels, which produce electricity directly and are more expensive than solar panels, which simply heat water.

One interesting example of profitable green architecture is a development of houses in Guillena north-east of Seville, which has photovoltaic panels on its roof, to make electricity and sell it back to the network, with the proceeds going to the houses´ owners. The houses are heated using carbon-neutral biofuel (olive pits, a typical waste product), have lower consumption and lower emissions.