In this 2012 study, the Lio & Associates team developed policy recommendations grounded in the analysis of a large dataset and empirical field evidence. This project required the firm to analyze over 500,000 house files from the NRCan’s ecoENERGY for Retrofits program as part of a background study for the Ontario Ministry of Municipal Affairs and Housing to identify options for energy efficiency requirements for residential renovations. The dataset was distilled down to just over 350,000 house files pertaining to the province of Ontario and was further analyzed and batched into construction time cohorts spanning years from 1749 to 2009.  The analysis assessed the homogeneity of the housing characteristics that define the energy efficiency of a building. The data was graphed and analyzed to identify patterns for each specific house characteristic.  The data set was further distilled down to a sample of just over 100,000 house files that defined housing archetype benchmarks for existing Ontario housing built from 1749 to 2009. This multi-step data analysis process allowed the Lio & Associates team to use discrete archetypes for the simulation of the cost effectiveness of various renovation scenarios.