Project Context and Funding
Alberta Ecotrust Foundation (AEF) initiated this project after receiving funding from the Code Accelerator Fund (CAF) from Natural Resources Canada (NRCan). A deliverable of this funding was in-depth research into construction permit data, specifically focusing on energy performance in the Tiered energy codes.
Research Execution and Municipal Engagement
To execute this research, the Alberta Ecotrust ENBIX program has and continues to engage with several interested municipalities seeking a better understanding of the energy performance associated with new construction permits within their jurisdictions. This collaboration was designed to offer insights into building efficiency trends at different municipalities in Alberta.
Scope of Analysis: Building Code and Performance Metrics
The analysis concentrated on two key categories within the National Building Code of Canada (NBCC):
- Part 9 Buildings: Typically smaller, simpler structures, including most residential homes.
- Part 3 Buildings: Larger, more complex structures, often commercial, institutional, or multi-unit residential buildings.
The resulting reports provide a detailed picture of the Tier levels achieved at the time of permitting. The National Building Code of Canada introduced an energy-efficiency tiered system in which higher tiers represent better performance.
The reports segment the analysis to illustrate performance across various building components and systems:
Building Envelope Performance: This includes the effectiveness of the thermal boundary, specifically analyzing the performance of:
- Walls
- Roofs
- Windows
- Air tightness
Active System Performance: This focuses on the efficiency of mechanical systems within the building:
- Space Heating Systems
- Ventilation Systems, particularly Heat Recovery Ventilators (HRVs)
- Domestic Hot Water (DHW) Systems
Important Caveats and Limitations of the Data
It is crucial to interpret this data within its defined scope, as it represents a specific point in time and methodology:
- Modelling vs. Reality (Point-in-Time Data): The performance data presented in the reports is derived exclusively from energy models submitted as part of the permitting application process. These models are based on design specifications, not actual performance.
- Exclusion of Actual Consumption Data: This research does not account for actual, post-occupancy energy consumption. Actual energy use can vary significantly based on occupant behaviour, weather, and system commissioning, and is not a component of the permitting performance models, which are strictly defined by building code modelling guidelines.
- Potential for Higher Performance: There is a strong possibility that some of the study buildings may actually be constructed to a performance level higher than the minimum requirements stipulated in the permit application. This is particularly common with performance aspects like air tightness, where builders may achieve excellent results through quality control. However, they are only required to model an assumed performance, rather than the actual performance achieved and assessed through testing.
City of Edmonton Part 9 Performance Path Study: Summary
