Graduated from the Polytechnic School of Architecture and Urban Design of Algiers, Algeria (EPAU) in 1997. He then completed a master degree at University College London, The Bartlett School: (M.Sc. in Environmental Design and Engineering in 1999).
In 2005 He was awarded a PhD in Thermal Comfort in Buildings at London Metropolitan University. El-khier has presented, and published his research in several international conferences in UK and abroad, and is a member of the Network for Comfort and Energy Use in Buildings (NCEUB) since 2004.
He has developed interests in environmental design and sustainability, advanced thermal modelling, thermal comfort in buildings, daylighting, artificial lighting and low energy design architecture.