Summary: Cool roofs are designed with materials that reflect more sunlight than conventional roofs, reduce building heat retention, and in turn reduce the urban heat island effect. Cool roofs can reduce internal building temperatures by up to 30%.
Implementation: Initiate grant program to fund installation of cool roofs for eligible new and existing properties (e.g. low-income households).
Considerations for Use: Areas with cold winters will trade-off reduced heat retention during warmer months with increased heating needs and moisture buildup during colder months. Cool roofs work best in areas with uniform building heights. Shorter buildings may cause glare on taller buildings. Depending on the treatment applied, cool roofs lose some surface reflectivity over time. The cost of coating materials will vary based on selected coating and local availability. Integrating cool roofs in new construction is more cost effective than a retrofit, but cool roofs are still one of the most affordable and approachable retrofit measures.
- Policy Levers: The mechanism municipalities can use to actualize the intervention. These policy levers will likely be used in combination with each other.
Funding and FinancingThe allocation of public or philanthropic funding or private financing to implement projects, including risk transfer mechanisms.
- Trigger Points: Opportunities for municipalities to implement risk reduction and preparedness interventions based on the policy lever, building on the United Nations Environment Programme triggers used in the Beating the Heat handbook (2021).
No-regrets actions (low cost/low effort but substantial benefit)Interventions that are relatively low-cost and low effort (in terms of requisite dependencies) but have substantial environmental and/or social benefits.
- Intervention Type:
Buildings and Built Form
Buildings, Informal Settlements,
- Target Beneficiaries:
Residents; Heat-vulnerable communities
- Phase of Impact:
Risk reduction and mitigation
Number of buildings compliant with provision; Energy savings by building; Indoor air temperature reductions; Outdoor ambient air temperature
- Toronto Eco-Roof Incentive Program (Kresge, Pg 18)
- Intervention Scale:
- Authority and Governance:
City government; State/provincial government
- Implementation Timeline:
Short-term (1-2 Years)
- Implementation Stakeholders:
- Funding Sources:
Private investment; Public investment
- Capacity to Act:
Low; Medium; High
- Public Good:
- GHG Reduction:
- Co-benefits (Climate/Environmental):
Reduce greenhouse gas emissions
- Co-benefits (Social):
Save on utilities; Improve the public realm