Prepared by Kim Perrotta, CHASE, April 2024
When working to influence policies and investments in local communities, it is important to recognize the intersection between population health, health equity, and sustainability. Communication surveys indicate that people are more likely to support climate-related policies when they understand that those policies can produce immediate health benefits. In addition, when investments are being made in local communities to transition away from fossil fuels that are driving climate change, it is essential that consideration be given to how those investments can improve population health and reduce social inequities. Programs and policies that encourage green buildings and building retrofits have the potential to improve health and health equity by improving indoor environments and climate resilience, and cutting energy costs, while reducing emissions of greenhouse gases that cause climate change.
Energy Efficient Buildings Fight Climate Change
Buildings are responsible for 13% of the greenhouse gases (GHGs) emitted in Canada;[1] 18% when the electricity used in buildings is included.[2] About 90% of these emissions come from the use of natural gas in furnaces, water heaters, and stoves, with 10% coming from the generation of electricity used in buildings.[3] The International Energy Agency estimates that energy demand for heating our buildings in Canada could be reduced by 85% by 2050 by improving building envelopes and shifting from furnaces to heat pumps.[4]
Three reports produced by the Taskforce for Housing and Climate found that Canada could lock in an additional 147.2 million tonnes (MT) of greenhouse gases (GHGs) per year by adding 5.8 million homes to Canadian cities if we apply weak building and development standards to their design and construction. Those reports indicate that those GHGs could be reduced to as little as 43 MT/year if aggressive policy approaches are applied to:
- Building materials and design (e.g., single-family homes vs multi-family units)
- Building performance (e.g., energy efficient design/technologies)
- Land use decisions (e.g., sprawled vs walkable neighbourhoods).[5]
Energy Efficient Buildings Reduce Outdoor Air Pollution
Air pollution continues to be a significant source of illness, chronic disease, and premature deaths in Canada. Buildings that are heated with oil and natural gas can release substantial quantities of pollutants into the air.[6] These air pollutants can be particularly problematic in urban areas that are impacted by air pollution from heavy traffic, industry, and/or upwind sources. Energy analysts note that extensive building retrofits that substantially reduce the use of oil and natural gas can result in substantial reductions in air pollution.[7]
Indoor Environments can Harm Health
A broad range of negative health outcomes can result from extreme temperatures, allergens and infections, dampness and mould, and air pollutants encountered indoors. Poor indoor environments have been associated with eye and respiratory irritation, hay fever, asthma, respiratory infections, and cardiovascular disease. Sources of indoor health risks can include:
- outdoor air pollutants and indoor air pollutants from fireplaces, cooking appliances, and heating equipment;
- air toxics released from building materials, furnishings, and consumer products;
- radon gas that can enter buildings through cracks in foundations;
- allergens such as dust mites, mould, and pet dander; viral,
- bacterial, and fungal infections that result from over-crowding, poor ventilation, or contamination of heating, ventilation and air conditioning (HVAC) systems; and
- second-hand tobacco smoke.[8]
Indoor Environments can Amplify Health Inequities
Older people, individuals with pre-existing health conditions, and people living in crowded or materially deprived conditions are more vulnerable to the health risks presented by poor indoor environments. They may also be at greater risk of exposure to these environments. In addition, these populations often have fewer resources to protect themselves, or recover, from climate-related events such as heat waves, floods and wildfires. [9]
Energy Efficienct Buildings Improve Health and Health Equity
Highly energy efficient buildings can improve indoor air quality, comfort, and noise levels with better ventilation, air filtration, and high levels of insulation. Correct ventilation rates can reduce levels of indoor air pollutants, efficiency filters can limit infiltration of outdoor pollutants and allergens, and high levels of insulation can minimize the penetration of cold, heat and sound.[10]
Building retrofits that improve the comfort and quality of indoor environments can also improve overall health, respiratory health, and mental health, with particular benefits for those with pre-existing respiratory conditions.[11] Multi-unit buildings retrofitted to increase energy efficiency have also been shown to improve occupant comfort and/or health.[12] This was the case for a Canadian study that examined energy efficiency retrofits that were conducted in multi-unit residential buildings that housed seniors, families, and single adults.[13]
Indoor Environmental Quality (IEQ) experts have noted however that building retrofits that increase the airtightness of buildings can produce negative health impacts by increasing levels of indoor air pollutants. These negative effects can be avoided, they note, with mechanical ventilation that includes heat recovery and air filtration and/or the removal of indoor sources of air pollution.[14]
Extreme Heat Claims Lives
Extreme heat events, that will become more frequent and intense with global warming, pose a significant risk to people in Canada. They can aggravate cardiovascular and respiratory conditions, and increase emergency room visits, hospital admissions, and premature deaths. The 2021 heat dome that hit British Columbia (BC) gave rise to over 600 premature deaths.[15] A few studies have found that extreme heat is increasing rates of premature deaths in cities across Canada.[16] Extreme heat has also been linked to adverse reproductive outcomes such as miscarriages and congenital defects and increases in aggressive behaviour and violent and non-violent crimes.[17], [18]
The experience with the BC heat dome re-affirmed that extreme heat poses a much greater risk for some populations. During the BC heat dome, death rates were much higher for people who live on low incomes, for those who live in homes without air conditioning, and for those who live in neighbourhoods with lower levels of greenness. They were also much higher for those between the ages of 65 and 74.[19]
Building Retrofits can Improve Climate Resilience
Building retrofit programs can be designed to strengthen climate resilience as well as energy efficiency. Improved roof insulation, roof coatings that reflect more solar energy, and air conditioning can mediate indoor temperatures. Particle filtration systems can reduce exposure to wildfire smoke.[20] Backflow valves installed in basement drains can prevent flooding of basements and exposure to mould. And fire-resistant roofing materials can be used to help protect people and their property from wildfires.[21]
Heat Pumps Increase Climate Resilience
Heat pumps that operate on electricity are much more energy efficient than electric baseboard heaters and furnaces that run on oil or natural gas. Over the last 5 to 10 years, air source heat pumps have been improved so they can now heat buildings in temperatures as low as -25°C. These cold climate air source heat pumps can completely replace conventional heating systems, while also cooling buildings in the summer months. They use up to 70% less energy than conventional home heating systems, so they can cut costs for homeowners and renters while also cutting emissions of GHGs and air pollutants.[22], [23], [24] However, the upfront cost of installing heat pumps can limit many households from installing them.
Building Retrofits Reduce Energy Poverty
Energy efficiency programs that substantially cut energy costs can also reduce health inequities by reducing energy poverty. Energy poverty forces some households to choose between the energy needed to heat their homes and other essentials such as healthy food, clothing, and medicine. Almost one in ten households in Canada spend more than 6% of their income on energy.[25] Energy poverty is associated with an increased risk of cardiovascular and respiratory diseases, hospital admissions, and premature deaths, as well as poor general and mental health.[26]
Gas-fired Stoves Affect Indoor Air Quality
For decades, there have been concerns about the health impacts that might be associated with the use of natural gas in stoves and ovens in homes.[27] Available evidence indicates that children living in homes with gas stoves are 42% more likely to have asthma than those living in homes with electric stoves.[28] [29]
- Federal, provincial, and municipal energy efficiency programs that encourage home energy retrofits with loans and grants
- Programs designed to encourage retrofits in affordable housing and low-income households
- Green building standards that mandate energy efficiency standards and climate resilience for all new buildings
- Building performance standards that mandate improvements in energy efficiency in existing buildings over time
- Stop governments from subsidizing natural gas hook-ups for new homes
To learn more, see the report and blogs produced by CHASE with the CPHA and OPHA:
- Report: Climate Change, Population Health and Health Equity: Public Health Strategies and Five Local Climate Solutions that Produce Health and Health Equity Benefits
- Blog: Public Health and Planning Co-creating Green Buildings and Green Streets in Ottawa
- Blog: Swapping Wood Stoves for Heat Pumps in Cowichan Valley, BC
[1] Environment and Climate Change Canada. 2022. 2030 Emission Reduction Plan – Canada’s Next Steps for Clean Air and a Strong Economy. Backgrounder.
[2] Government of Canada. 2023. Green Buildings. Webpage.
[3] Toronto Atmospheric Fund (TAF). 2022. GTHA Carbon Emissions Inventory. Summary
[4] International Energy Agency. 2019 as cited by Macfarlane R Perrotta K. 2019. Module 5: Climate Change Solutions with Immediate Health Benefits. Climate Change Toolkit for Health Professionals. Edited by K Perrotta. Canadian Association of Physicians for the Environment.
[5] https://housingandclimate.ca/ghgs/
[6] World Green Building Council. Air quality in the built environment.
[7] Torrie R, Bak C, Heaps T. 2020. Building Back Better with a Bold Green Recovery. Synthesis Report
[8] Vardoulakis S. 2015. Impact of climate change on the domestic indoor environment and associated health risks in the UK. Environment International. Vol. 85
[9] Kosatsky et al., 2009; Bélanger et al., 2014; Bélanger et al., 2016 as cited by Health Canada. 2022. Health of Canadians in a Changing Climate – Advancing our Knowledge for Action.
[10] Chatterjee S Urge-Vorsatz D. 2021. Measuring the productivity impacts of energy-efficiency: The case of high-efficiency buildings. Journal of Cleaner Production. Vol 318.
[11] Hamilton et al. 2015 as cited by Macfarlane R Perrotta K. 2019. Module 5: Climate Change Solutions with Immediate Health Benefits. Climate Change Toolkit for Health Professionals. Edited by K Perrotta. Canadian Association of Physicians for the Environment.
[12] Chatterjee S Urge-Vorsatz D. 2021. Measuring the productivity impacts of energy-efficiency: The case of high-efficiency buildings. Journal of Cleaner Production. Vol 318
[13] Toronto Atmospheric Fund (TAF). 2018. Energy Efficiency and Indoor Environmental Quality. Pre- and Post-retrofit Survey Analysis.
[14] Vardoulakis S et al. 2015. Impact of climate change on the domestic indoor environment and associated health risks in the UK. Environment International. Vol. 85
[15] Chief Coroner of British Columbia. 2022. Extreme Heat and Human Mortality: A Review of Heat-Related Deaths in B.C. in Summer 2021
[16] Guo et al., 2018 and Xu et al., 2016 as cited by Health Canada. 2022. Health of Canadians in a Changing Climate – Advancing our Knowledge for Action.
[17] Auger et al., 2014; Auger et al., 2017d; Auger et al., 2017b; Auger et al., 2017c as cited by Health Canada. 2022. Health of Canadians in a Changing Climate – Advancing our Knowledge for Action.
[18]Health Canada. 2022. Health of Canadians in a Changing Climate – Advancing our Knowledge for Action. (Mares, 2013; Ranson, 2014)
[19] Henderson SB et al. 2022. Analysis of community deaths during the catastrophic 2021 heat dome, EnvironmentalEpidemiology: Vol 6, No1
[20] Fisk W. 2015. Review of some effects of climate change on indoor environmental quality and health and associated no-regrets mitigation measures. Building and Environment. Vol 86.
[21] Mee C. 2019. Module 7: Preparing for Climate Change in our Communities. Climate Change Toolkit for Health Professionals. Edited by K Perrotta. Canadian Association of Physicians for the Environment.
[22] McDiarmid H. McDiarmid Climate Consulting. 2022. An Analysis of the Financial and Climate Benefits of Electrifying Ontario’s Gas-Heated Homes by Installing Air-Source Heat Pumps. Ontario Clean Air Alliance.
[23] Janssen E. Erik Janssen. 2023. Interview-April 2023. Research Scientist, Sustainable Technologies Evaluation Program | Education and Training, Toronto and Region Conservation Authority.
[24] Turner Chris. 2023. Heat pumps are hot in the Maritimes. Blog. Canadian Climate Institute.
[25] Das R Martiskainen M. 2022 Keeping the Lights on. David Suzuki Foundation.
[26] Riva Mylene et al. 2023. Energy poverty: an overlooked determinant of health and climate resilience in Canada. Canadian Journal of Public Health. Vol. 114.
[27] Anenberg A et al. 2022. Long-term trends in urban NO2 concentrations and associated paediatric asthma incidence: estimates from global datasets. The Lancet Planetary Health. Vol 6.
[28] Lin W. Brunekreef B Gehring U. 2013. Meta-analysis of the effects of indoor nitrogen dioxide and gas cooking on asthma and wheeze in children. International Journal of Epidemiology, Volume 42.
[29] Paulin et al 2023 Gas Stoves and Respiratory Health. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10704234/pdf/AnnalsATS.202306-533VP.pdf