This was how the building containing my house and Energy Advisory Associates’ office appeared on many days this winter, seen against an intense blue sky. Well, almost like this; the picture was actually taken late in autumn 2014.
Yes, the weather has been cold by UK standards. But in a passive solar building, the solar energy available matters more than the outside temperature and there has been plenty of solar energy this winter. In a solar house, one would not always guess that it is uncomfortably cold outside from the relatively warm temperature indoors.
For a passive solar building, ‘winter’ is mostly over by now. In a ‘normal’ or ‘average’ year’, anyway. February and March are on average as cold as December and January, but the sun is higher in the sky.
At present, this 110 m2 building is consuming about 800 watts of heat. The Cropthorne House, which was designed later, with my help, has been at 20oC on passive solar alone for large parts of winter 2014-15  .
I am writing a book to give an account of the experience with this house, explain the principles to others and help them to achieve more effective results. There is a separate website also now available giving more details of the project and how it achieves low, hopefully negative, CO2 emissions .
 Coe, Mike, personal communication (January 2015).