This website is a guide and is not intended to replace professional advice. Please see our disclaimer for more information!
Low Carbon Guide for Multiplex Conversions
In Toronto, the energy use in existing buildings and greenhouse gas emissions from new construction make up 60% of the city’s carbon emissions.
The Low Carbon Guide for Multiplex Conversions was created as an accessible starting point for non-professionals. It offers practical guidance for balancing cost, performance, and carbon impact with a focus on making informed choices about construction materials and building systems like heating and cooling.
Climate responsibility is starting to shape large-scale development, but it should also play a role in small projects. We hope citizen developers see their multiplex projects not only as part of the housing solution but also as part of the climate solution. And that this report can serve as a starting point for making sustainable construction decisions. With the right knowledge in the right hands, small choices can add up to make a big difference for both our housing needs and the health of our planet.
The Low Carbon Guide for Multiplex Conversions was created as an accessible starting point for non-professionals. It offers practical guidance for balancing cost, performance, and carbon impact with a focus on making informed choices about construction materials and building systems like heating and cooling.
Climate responsibility is starting to shape large-scale development, but it should also play a role in small projects. We hope citizen developers see their multiplex projects not only as part of the housing solution but also as part of the climate solution. And that this report can serve as a starting point for making sustainable construction decisions. With the right knowledge in the right hands, small choices can add up to make a big difference for both our housing needs and the health of our planet.

Prepared by:
Rehousing
Ha/f Climate Design
Rehousing
Ha/f Climate Design
Date:
July 2025
July 2025
Team:
Samantha Eby (ReHousing)
Michael Piper (ReHousing)
Janna Levitt (ReHousing)
Rashmi Sirkar (Ha/f Climate Design)
Kelly Alvarez Doran (Ha/f Climate Design)
Juliette Cook (Ha/f Climate Design)
Ryan Bruer (Ha/f Climate Design)
Miriam Palmer (Ha/f Climate Design)
Samantha Eby (ReHousing)
Michael Piper (ReHousing)
Janna Levitt (ReHousing)
Rashmi Sirkar (Ha/f Climate Design)
Kelly Alvarez Doran (Ha/f Climate Design)
Juliette Cook (Ha/f Climate Design)
Ryan Bruer (Ha/f Climate Design)
Miriam Palmer (Ha/f Climate Design)
THIS WEBSITE, INCLUDING ALL DATA AND INFORMATION INCORPORATED HEREIN, IS BEING PROVIDED FOR INFORMATION PURPOSES ONLY AND IS NOT INTENDED FOR AND HAS NOT BEEN APPROVED FOR USE FOR CONSTRUCTION AT ANY LOCATION.
For certainty, ReHousing (Canada), The University of Toronto, John H. Daniels Faculty of Architecture Landscape and Design, and LGA Architectural Partners provides no representation or warranty regarding any use of or reliance upon this website, including any representation or warranty that this website complies with applicable laws (including any applicable zoning by-laws or building code requirements) and any representation or warranty that any cost estimates included in or based upon this website have been validated by the applicable market. Any use of or reliance upon this website by any person for any purpose shall be at such person’s sole risk and ReHousing (Canada), The University of Toronto, John H. Daniels Faculty of Architecture Landscape and Design, and LGA Architectural Partners shall have no liability or responsibility for any such use of or reliance upon this website by any person for any purpose. Prior to any use of or reliance upon this website by any person for any purpose, consultation with a professional architect duly licensed in the applicable jurisdiction is strongly recommended.
For certainty, ReHousing (Canada), The University of Toronto, John H. Daniels Faculty of Architecture Landscape and Design, and LGA Architectural Partners provides no representation or warranty regarding any use of or reliance upon this website, including any representation or warranty that this website complies with applicable laws (including any applicable zoning by-laws or building code requirements) and any representation or warranty that any cost estimates included in or based upon this website have been validated by the applicable market. Any use of or reliance upon this website by any person for any purpose shall be at such person’s sole risk and ReHousing (Canada), The University of Toronto, John H. Daniels Faculty of Architecture Landscape and Design, and LGA Architectural Partners shall have no liability or responsibility for any such use of or reliance upon this website by any person for any purpose. Prior to any use of or reliance upon this website by any person for any purpose, consultation with a professional architect duly licensed in the applicable jurisdiction is strongly recommended.