Dr Stephen Ledbetter

BSc PhD CEng FICE FSFE

Profile

Stephen Ledbetter is Director of the Centre for Window and Cladding Technology his interests cover all aspects of building envelopes with particular emphasis on structural engineering and procurement of building envelopes. Stephen teaches on many units of the MSc in façade engineering and in industry.

Stephen is a civil engineer by background and a façade engineer by practice, he is a Fellow of both the Institution of Civil Engineers and the Society of Façade Engineers. Stephen has been the inaugural Director of the Centre for Window and Cladding Technology for over twenty years and has developed education, training and standards for industry based on research and industry collaboration.

Stephen has published widely in the field of façade engineering and has run many conferences at Bath including ICBEST 2007 and Glass in Building (1 and 2). He is a member of the Institution of Structural Engineers study group on glass, was the Chair of COST Action C13 on glass and is the UK representative on the CEN Standard committee for curtain walling.

Stephen was the inaugural Editor of the Institution of Civil Engineers Journal ‘Construction Materials’; he is a member of the European Façade Network of universities and has sat on the Technical Committees of many conferences.

Before moving in to façade engineering, Stephen’s interests were in earthquake engineering and he was a Chairman of the Earthquake Engineering Field Investigation Team (EEFIT); He reported on earthquakes in El Salvador, Romania and California. He has drafted the European Standard requirements for curtain walling response to seismic events.

Research

Stephen’s research into facades began with a study comparing the cladding industry structure and practice around the globe. His research progressed through materials (advanced glasses, gaskets, sealants, natural stone panels and nickel sulphide in toughened glass), physics (heat transfer, environmental control glasses, shading and automated facades) and industry processes (procurement, specification, failure mode and effects analysis and supply chain studies). The output from this research has been published as academic research papers, standards and best practice guides for industry and course content.

Stephen’s research interests have changed with changes in façade usage and changing demands on façade performance. His current research interests include built-up and layered walls, durability of building envelopes, building information modelling for facades and embodied carbon.

• Built-up walls give rise to problems of integrating the design process, appropriate detailing and the interdependence of different systems within a wall.
• Durability of building envelopes depends on materials and operating environments but the consequences of durability depend on inspection, maintenance and repair regimes. The aim is to develop predictions of performance that enable appropriate and economic combinations of materials to be adopted what ever the required design life.
• Building information modelling presents particular problems for façade engineers. Walls contain many components and great detail and whilst this is of importance to the manufacturer it is irrelevant to the architect and may overburden a BIM. Ascertaining the appropriate levels, detail and functionality for a façade model is in the early stages and requires considerable clarification.
• Embodied carbon has been well studied for individual materials; however, complex walls are systems comprising many materials and substitution of one material for another may often have unintended consequences. Work is required to study the optimisation of embodied carbon at systems level rather than at a material or component level.

Teaching

• MSc Facade Engineering

Publications