Independent (UK): For many architects, a rugged rock face might not seem like the perfect location for an energy-efficient, stylish house. Yet the architects of Villa Astrid, near Gothenburg in Sweden, have managed to create a striking two-storey family house which not only interacts dramatically with its surroundings but which also has impeccable eco-credentials. It was a challenge that the architects Wingardhs relished. They had to squeeze the house between two existing buildings at the same time as …