To date, few experiments have attempted to apply lean principles within the residential energy retrofit sector. This research focuses on factors that influence the setting of target costs in residential energy retrofit assessments. A case-study-based cost-performance model is presented. The model is centered on savings/investment ratios and describes the variability of upgrade costs and their relationships with community size; house characteristics; site constraints; project site complexity; labor and materials: and the production operations design of installation procedures. The cost model for the community studied indicates that savings/investment ratios increase and per-unit costs decrease as the number of housing units to be retrofitted increases. The project is estimated to achieve approximately 50% per-unit cost savings from the initial baseline of a single home estimate. Significant labour cost savings are achieved by completing more attics in one day and/or by increasing the production rate of the installation crews. Per-unit overhead costs are cut significantly as the scope of the project expands. Based on this cost performance model, the study proposes a set of target cost planning principles to support energy efficiency retrofit decisions by facility managers of centrally-managed housing communities.
Energy efficiency measures, cost modeling, home energy assessments, target cost planning, residential energy retrofits
Whelton, M.G. , Riley, D.R. & Carlsen, B. 2012, 'Cost Performance of Energy Efficiency Measures in Residential Retrofit Projects' In:, Tommelein, I.D. & Pasquire, C.L., 20th Annual Conference of the International Group for Lean Construction. San Diego, USA, 18-20 Jul 2012.