Much research has been carried out by wide reading.

Solar Heating Systems for Houses -- Werner Weiss & Details for Passive Houses.

Consultation with the Centre for Alternative Technology (CAT).

Reading and discussing on the Green Building Forum has been a great help and I would like to thank all those who have inputted via that route.

My research began in 1978 with a visit to the Saskatchewan Conservation House. It is sad to read their report produced in 1977 and realise how little progress we have made since then. They had an evacuated tube solar panel back then and had them at an angle of 70 degrees!!! see