Multi-unit residential buildings (MURBs) comprise a significant portion of the housing stock in North American cities. Several studies have identified opportunities to reduce energy consumption at these buildings. Building enclosure retrofits present one of the largest opportunities for significant energy savings. A previous study by the authors into energy savings achieved in MURBs as the result of full building enclosure renewals work found that, on average, a reduction of 8% of total energy consumption was realized through projects undertaken primarily to address moisture ingress damage, and not specifically for energy savings (RDH 2012). This study also highlighted that full building enclosure retrofits of existing MURBs have the potential for much larger savings, and when properly implemented along with HVAC upgrades, total building energy savings in the order of 20-50% and suite space heat savings of up to 90% can be achieved.
As a result of this research work, a pilot project was undertaken to perform an energy efficient building enclosure retrofit and HVAC upgrade of a 1980’s vintage high-rise MURB in Vancouver, BC, predicted to yield a total energy savings of over 25%. This paper details the high performance enclosure retrofit that was completed. Modeled energy savings are compared metered energy use. A payback period of 5 years was calculated for installing triple glazed, fiberglass frame windows compared to code minimum windows. The findings and lessons learned from this project will assist in planning for future high performance enclosure retrofits to lower the energy consumption of the existing building stock.