The main purpose of the meeting was to provide guidance on modelling parameters for Tier 3 and 4 archetypes to NRC Research modellers. NRC presented the approach used for Tiers 2 and 5, followed by a discussion on key issues:

• Compliance criteria for small (≤ 300 m3 ) buildings
  • It is well known that smaller dwellings inherently consume less energy, and in some cases, the archetype does not “fit” with the compliance path (e.g. basement unit with no ceiling R-value as an Energy Conservation Measure). 
• Consistency between points and packages
  • This, again, is problematic for the NRC modeller as there are nuances that the model does not consider.
• Airtightness requirements at Tiers 3 & 4
  • CHBA voiced their concern about mandatory airtightness testing for Tier 3, which was well received by the chair and members and consensus was reached to reflect CHBA’s recommendation and not make airtightness testing mandatory for Tier 3.
• Heat pumps at Tier 3 and/or 4
  • NRC will model all the archetypes with heat pumps as an option, along with gas and oil furnaces.
• Drainwater heat recovery
  • A member from Alberta mentioned that these units are rarely installed in their Province, and CHBA raised that as a red flag. It was decided that drainwater heat recovery units will not be mandatory for Tier 3.

For more information, please contact alex.bols@chba.ca