Passive Solar Angled Windows
The Equinox House near Kavarna, Bulgaria features a sloping glass frontage, designed by Ignatov Architect to be parallel to the angle of the sun at noon on the summer solstice, when the sun is at its highest point in the sky.
The large extra efficient windows are angled to avoid summer heat and to maximise the small amount of winter energy from the sun - the principle is known as passive solar heating. The Equinox house is also constructed to be as airtight as possible, acheiving 50% better than passive house standards. Along with excellent insulation, this yeilds a 90% reduction in heating requirments.