Christopher Day was an eco-architect, self-builder and sculptor. He designed buildings in line with the ecological principles of his books and won several awards. A former visiting professor at Queen's University, Belfast, he also designed, consulted, taught and lectured in over 20 countries worldwide, from California to Siberia, Sweden to New Zealand: wide-ranging climates and cultures. He was awarded an MBE for his services to architecture and innovation in the 2016 Queen's Birthday Honours list. His previous publications include Places of the Soul 3rd edition, Consensus Design, Environment and Children and Spirit and Place, also available from Routledge.

Sadly, Chris passed away in the spring of 2019 shortly after we completed the final draft of this manuscript. He will be sorely missed by his wife, family and all who knew him. It was a privilege and a joy to have worked with Chris on this project, of which I hope he would have been proud.

Julie Gwilliam is a Senior Lecturer in Architecture at the Welsh School of Architecture, Cardiff University, UK, as well as Postgraduate Dean for the College of Physical Sciences and Engineering. For ten years she led the MSc in Theory and Practice of Sustainable Design and she continues to contribute to teaching on the subject of sustainability throughout the school, including the MA in Urban Design.