Solar tower in Spain

A nice step forward – and, in a way, backwards towards Spain’s tradition of sustainable energy use in home design. Until recently, Spanish domestic architecture was inherently energy efficient. The walls were thick stone or brick, and the resulting thermal mass moderated the interior temperatures. Since a lot of Spain is at altitude, with hot summer days yet cool nights, it worked to keep houses comfortable day round. Added to that was the use of white shutters that were pulled down to block sun through the windows in the heat of the day during the warm months, helping to keep the interiors cool. Today, of course, walls are skimpy and AC is a given. I suspect that going back to the ancient vernacular methods of construction would save even more energy than solar water heaters, by making AC less important.