Book Description
As newly constructed buildings are increasingly able to achieve very low and even net zero energy consumption targets, improving the energy performance of existing buildings has become a more pressing concern. Historic buildings represent a unique subgroup of the existing building stock. By definition, these buildings hold special societal significance. They were also constructed using materials and methods no longer common in contemporary building practice, and operated to meet thermal comfort conditions no longer considered acceptable. The need to maintain their significance and avoid damage to historic building fabric imposes additional constraints.Since the advent of building energy codes in the 1970s, the dominant approach to energy efficiency in historic buildings has been exemption. Early studies suggested that older buildings had lower energy consumption per square foot than newer ones, and preservationists have attributed this trend to the presence of inherent energy-saving features in these buildings. These findings, combined with the desire to preserve significance, led to the status quo in which historic buildings are exempt from energy codes, leaving open questions about appropriate target setting and energy retrofits.This dissertation re-evaluates the dominant approach to energy efficiency in historic buildings using contemporary data and analysis methods. Each of the major parts of the established narrative are examined. First, the claim that older buildings use less energy is evaluated using a statistical model constructed from nationally representative data. Second, the concept of inherent energy-saving features is explored using a novel quantitative method. The method developed here combines building energy simulation with regionalized sensitivity analysis and tree-based classification models, and is demonstrated using a case study historic building on the Penn State campus. Third, the technical problems implementing energy retrofits in historic buildings are synthesized via a review of recent research. Overall, the findings from this dissertation suggest that the preservation community relinquish the argument that historic buildings are inherently energy efficient in favor of a more utilitarian approach to energy retrofits in these buildings.