Paul F. McCombie graduated with a BA in engineering from Cambridge University in 1981. He then worked for a consulting engineer and studied for an M.Sc in soil mechanics at Imperial College, London. After three years with Netlon Limited, in 1990 he moved to the University of Bath, where he served as director of studies for civil engineering and head of civil engineering. He has been deputy head of department since 2009. In 2010, he was awarded the Institution of Civil Engineers John Mitchell Medal for his research on dry stone retaining walls within the BRE Centre for Innovative Construction Materials (BRE CICM). Jean-Claude Morel was director of research (equivalent to professor) at Ecole Nationale des Travaux Publics de l'Etat (ENTPE) in France. He is now professor of low impact buildings at Coventry University. He gained his Ph.D in 1996 from the University Joseph Fourier of Grenoble. In 1998, following an invitation from the architect Patrick Cohen, he initiated a series of research projects on drystone walls, at first with Boris Villemus, and later with Denis Garnier, Anne-Sophie Colas, and then Eric Vincens. He has carried out major research work on low-impact building materials, including a series of testing campaigns on full-scale dry stone retaining structures, on which he has published extensively. Denis Garnier gained his Ph.D in soil mechanics in the prestigious Ecole Nationale des Ponts et Chaussees (Paris, France), where he is now senior lecturer and teaches the course on continuum mechanics. He is also professor at ENTPE (member of the University of Lyons, France), where he teaches the course of yield design analysis theories. He started his research in the team of Jean Salencon with Patrick de Buhan. He has carried out major research work on rock engineering and the stability modelling of drystone structures, mainly based on homogenization theories. He collaborates with Jean-Claude Morel of ENTPE in 3D modelling and full-scale experiments of dry stone masonries.