Key Concepts

Air Changes per Hour (ACH): The number of times the full volume of air in the building exchanges in an hour when a building is at a specified pressure. Also referred to as a “blower door test” this test measures the airtightness of the building, how much air leaks through the building envelope. 

Air Leakage Rate: A measure of the rate that air leaks through the building envelope per unit area of the building envelope, as recorded in Litres/(second/metre2) at a 75 Pascals pressure differential.

Authority Having Jurisdiction: Typically a municipality, and in some instances the province or territory, responsible for the oversight of construction activities. The authorities having jurisdiction are responsible for enforcing compliance with the building code.

Building code: a law or regulation that establishes specifications for the design and construction of residential or commercial buildings that ensure new construction meets minimum health, safety and performance standards. 

Building energy code: A regulatory standard that sets minimum efficiency requirements for new and renovated buildings and intended to result in reduced energy use and emissions over the life of the building. Energy codes are a subset of building codes, which establish baseline requirements and govern building construction. 

Building envelope: A building’s physical separation between the conditioned and unconditioned environment, including walls, floors, ceilings, windows, doors, etc.

Embodied carbon: The amount of carbon dioxide emissions and other global warming gases need to make construction materials. Embodied carbon includes the embodied energy used to extract, refine, process, transport and fabricate a building material.

Indoor Air Quality (IAQ): The state of the air within a building’s conditioned space. Good IAQ can be identified as one that is low in toxins, contaminants and odors. Balanced ventilation is critical to providing well ventilated spaces protected from outdoor air pollutants or by pollutants off-gassed from construction materials and building contents.

Indoor Environmental Quality (IEQ): The conditions inside the building such as air quality, access to daylight and views, acoustic conditions, and occupant control over lighting and thermal comfort. 

Mechanical Energy Use Intensity: The modelled amount of energy used by space heating and cooling, ventilation, and domestic hot water systems, per unit of area, over the course of a year, expressed in kWh/(metre2/year). 

Model code: Canada’s national model codes set out minimum requirements and form the basis of most building design in the country. It is a model set of requirements which provide for the health and safety of the public in buildings, which are produced nationally and published for adoption by authorities having jurisdiction (i.e. provinces and municipalities).  

Net Zero Energy (NZE): A building that produces as much energy on-site as it consumes annually. 

Net-Zero Energy Ready (NZEr): A building standard designated to make a building so energy efficient that it can easily produce as much energy as it consumes annually, if a renewable energy generating system (such as Solar, Wind and/or Micro-hydro) existed on-site. NZEr buildings are typically 80% more energy efficient than a typical new building, according to Natural Resources Canada.

Operational carbon: The carbon dioxide emissions and other global warming gases during the in-use operation of a building, that is all energy sources used to keep buildings warm, cool, ventilated, lit and powered. 

Pan-Canadian Framework National Framework for Clean Growth and Climate Change: A framework developed with provinces and territories and in consultation with Indigenous Peoples, to help meet Canada’s emissions reduction targets, grow the economy, and build resilience to a changing climate.

Performance path: A code compliance path that uses either absolute energy values, such as Thermal Energy Demand Intensity or Energy Use Intensity, to demonstrate compliance or energy modelling. The performance path offers the designer or builder the most flexibility in meeting the building energy code requirements. 

Prescriptive path: A series of prescriptive requirements a building is required to meet to demonstrate code compliance. Each element of a building is prescribed a minimum acceptable standard, typically outlined in a series of tables. For example, a specific minimum insulation value for different types of wall assemblies across different climate zones. A prescriptive path does not require energy modelling or calculations. 

Provincial/territorial building code adoption: Model codes have no force in law until they are adopted by an authority having jurisdiction. In Canada, that responsibility lies with the provinces, territories and in some cases, municipalities. 

Reference building: A model building used to identify how much less energy (in percentage) a new home will consume compared to the reference building built to base building code standards. 

Resilient buildings: Those buildings prepared to withstand climate risks like floods, wildfires, droughts, and extreme weather events. Resilient buildings also offer occupants stable temperatures in the event of an extended power outage or interruption in heating capacity.

Thermal Energy Demand Intensity (TEDI): A measure of the amount of annual heating energy required to maintain a stable interior temperature. TEDI considers heat loss through the envelope and passive gains, such as thermal energy generated by sunlight, occupants, or appliances. TEDI is calculated per unit of area of the conditioned space over the course of a year. It is expressed in kWh/(metre2/year). 

Tiered code: an incremental approach to achieving more energy efficient buildings. It is a progressive series of performance-based steps that start with a familiar base building code and each subsequent step becomes increasingly energy efficient. Sometimes referred to as a step code or stretch code.  

Total Energy Use Intensity: The modelled amount of total energy used by a building, per unit of area, over the course of a year, expressed in kWh/(metre2/year). It includes plug loads and process loads. Plug loads include appliances, lighting, entertainment systems, and all other electrical devices. Process loads include loads for heating, cooling, fans, and other mechanical systems.