Dr. Roberto Garay Martinez is a lead researcher in building physics, heat transfer, and energy systems for the built environment. He has been involved in research and engineering in relation to energy in buildings for ten years. He has been a staff member of the KUBIK test facility since 2011 and has taken part in the design teams of six experimental facilities in Europe and overseas. He has authored over 40 conference and journal papers, two patents and two books. He has also co-organized several international conferences and been appointed by external expert to conferences (3) and evaluation processes. Since 2017, he has been Project Coordinator of h2020 project RELaTED, a de-carbonized heat concept by means of low-T distribution, reuse of waste heat and incorporation of solar thermal systems at district and building scale.Mr. Antonio GARRIDO-MARIJUAN is a researcher in Energy in the Built Environment, with a background in energy simulation and data analytics for the built environment. He has been involved in research, energy modelling, engineering and experimental assessment for more than a decade, with participation on over 10 large European projects. His research activity was initiated at CIEMAT, with direct involvement in the development of innovative systems for a compromise between energy efficiency and indoor air quality. His also worked for the AIT, Austrian largest research centre, developing different tools and KPIs for energy performance assessment at district level. Since 2018, his research activity is carried out at Tecnalia, where he actively participates in the implementation and optimization of low-carbon energy systems such as fourth-generation district heating networks based on simulation tools and data analytics.