Perhaps the most dramatic feature of the Equinox House near Kavarna, Bulgaria is the sloping glass façade. Ignatov Architects designed it to be perfectly parallel to the angle of the sun at noon on the summer solstice, when the sun is at its highest point in the sky. It's the visible symbol of what is a very clever Passive House.
Andrew Michler writes at Evolo, calling it:
... a novel approach to achieving passive house energy performance. The home’s celestial name sake is well deserved for the careful consideration of solar orientation of the large, super efficient windows, angled to shed summer heat but absorb the fleeting winter energy. Extremely airtight construction testing at 50% better than passive house standards and super-insulation provides a 90% reduction in heating needs.