Wall Thermal Design Calculator

Effective R-value calculator with durability analysis

Click Here to go to the Calculator
The purpose of this online tool is to provide designers with climate zone-appropriate insulated wall assembly solutions that are easily comparable with national and provincial energy efficiency prescriptive provisions.

Each assembly lists:

  • Effective thermal resistance Reff* for complying with the National Building Code (NBC) for houses and the National Energy Code for Buildings (NECB) for larger buildings
  • Installed R-value for complying with the Ontario Building Code
  • Centre of cavity R-value for complying with the Quebec Construction Code.

*The calculation of effective thermal resistance is performed in compliance with NBC Subsection 9.36.5. of Division B.

Each assembly comes with a climate-specific colour-coded durability assessment, which has been determined considering computer analysis and field experience by building science experts in Canada.

title page icon wall thermal design catalogueList of Available Wall Assembliestitle page icon how to use the catalogueHow to Use the Wall Thermal Design Calculator
title page icon code requirementsCanadian Code Requirements for Above Grade Wall Thermal Designtitle page icon builder notesUnderstanding the Builder Notes
title page icon energy and thermalWall Thermal Design Performance Literature: Excerpts from the CHBA Manualtitle page icon durabilityUnderstanding the Building Science Durability Notes


Many thanks to the steering committee and project team for making this online tool possible:

Steering Committee

Alejandra NietoRoxul Inc.
BJ YehAPA – The Engineered Wood Association
Bob WilsonR.S. Wilson Building Inspection & Consulting Inc.
Christopher McLellanCanadian Home Builders’ Association
Cory McCambridgeAPA – The Engineered Wood Association
Dave HendersonBrookfield Homes
Gillian HaleyERA Architects Inc.
John Hockman JLHockman Consulting Inc.
Jieying WangFPInnovations
Paul Smith Mattamy Homes Corporation
Peter BirkbeckIcynene Inc.
Peter CulyerEIFS Council of Canada
Richard KadulskiSolplan Review
Robert MarshallCertainTeed SAINT-GOBAIN
 Todd Rogers City of St. Catharines
 Salvatore Ciarlo Owens Corning Canada
Silvio PlesciaCanada Mortgage and Housing Corporation
To join the committee or to discuss inclusion of more products in the tool, please contact Robert Jonkman – rjonkman@cwc.ca


Project Team

Project InitiatorRobert JonkmanCanadian Wood Council
Project Lead and Publishing ExpertCandice LuckbuildABILITY Corporation
Builder Lead and Field ExpertAndy OdingBuilding Knowledge Canada
Technical Lead and Building Science ExpertChris TimuskTimusk Consulting, George Brown College
Technical Project AdvisorMichael LiobuildABILITY Corporation
Technical Project AdvisorGord CookeBuilding Knowledge Canada
WUFI Expert PanelistGraham FinchRDH Consulting
WUFI Expert PanelistChris SchumacherRDH Consulting