Overview:

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: Set public goals to achieve a certain number or share of cool roofs or square footage within a target timeframe. These goals can be included in a strategic plan.

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:
  
  
  CommitmentGovernments set ambitious goals or targets to guide prioritization and investment.
• Trigger Points:
  
  
  Preparatory measures (actions to establish authority to act)Actions to establish/ ensure the authority to act when appropriate trigger-points occur.
• Intervention Type:
  Buildings and Built Form
• Sectors:
  Buildings

Impact:

• Target Beneficiaries:
  Heat-vulnerable communities, Residents
• Phase of Impact:
  Risk reduction and mitigation
• Metrics:
  Energy savings by building, Indoor air temperature reductions, Number of buildings compliant with provision, Outdoor ambient air temperature

Case Studies:

• NYC Cool Roofs Commitment

Implementation:

• Intervention Scale:
  Building
• Authority and Governance:
  City government
• Implementation Timeline:
  Short-term (1-2 Years)
• Implementation Stakeholders:
  City government
• Funding Sources:
  Public investment
• Capacity to Act:
  High, Low, Medium

Benefits:

• Cost-Benefit:
  Low
• Public Good:
  Low
• GHG Reduction:
  Medium
• Co-benefits (Climate/Environmental):
  Reduce greenhouse gas emissions
• Co-benefits (Social):
  Improve the public realm, Save on utilities