Energy-efficient retrofits for existing buildings : a multi-dimensional, comparative study of buildings in Hong Kong, Shanghai and Singapore, with focus on operation and maintenance

Abstract

Existing buildings greatly impact the environment through energy and water consumption, embodied carbon, and carbon emissions. Moreover, poor construction quality, inadequate architectural forms, and deteriorating equipment necessitate either demolition or retrofit. Of the two, green retrofits clearly offer the greatest potential energy savings. While their value and payback are now accepted across America, Europe, Japan and other developed countries, retrofit projects in developing countries like China, with its large population and fast-paced building demand, can be risky propositions to owners due to three main barriers: cost, insufficient payback period, and uncertainty regarding post-retrofit performance and savings. While research on energy efficient retrofits has been wide and deep, most research focus on the design and simulation of facilities and technologies, while missing two critical items – Indoor Environmental Quality and Human Factors – that if not taken into account, can greatly subvert any purported energy savings. This dissertation, on the issues and barriers surrounding green building retrofits, is posed as a methodological counterpoint to the existing process, trying to integrate what currently works – while introducing steps that take into account the crucial post-retrofit period – into a new framework that rebalances around three critical aspects of buildings: Equipment, Architectural Design, and Human Factors. Working from the hypothesis that green retrofits are feasible and can achieve substantial energy savings, the research begins with case studies in Hong Kong, Shanghai, and Singapore – high density, high GDP cities with the willingness and capacity to achieve such projects. The research is grounded in technical studies – from the Architect’s perspective – such as comparative analysis, field measurements, data collection, and computer simulation, seeking opportunities for a more holistic, multidisciplinary process to better achieve green retrofits. The dissertation finds that 1) The single most cost-effective Energy Conservation Measure (ECM) for cooling-load-only buildings is a lighting upgrade, followed by an energy-efficient air conditioning system, often achieved via a chiller plant; 2) The two non-cost measures with the most potential for energy savings are an appropriate Operating Schedule and Thermal Environment Set Point; 3) Operable design for occupants is the most efficient passive method for energy savings; 4) Due to the difficulty navigating the existing process, a comprehensive framework is needed that makes the whole process more feasible, clear, systematic, and under one frame; and 5) Having Architects play a greater role in the process can ensure that qualitative aspects are included alongside quantitative ones. These findings show us that energy-efficient retrofits of existing buildings must be interdisciplinary, but also human focused, since the post-retrofit period has high relevance. Thus, successful green retrofits should combine factors from the fields of Environmental Studies, Economics, Building Science, Architectural Design, Engineering, and Human Behavior. The aim of the research is to improve the existing retrofit process by expanding the scope of focus beyond the norm (technological simulations during the design process) and into post-retrofit, more human-centered territory. Finally, the dissertation offers a Practice Guidebook, so that decision makers can more easily navigate this process, ultimately encouraging them to undertake more green retrofits.