Overview:

Summary: Cool walls apply treatments to building facades to reduce the solar absorption of a building's walls, which can reduce the urban heat island effect.

Implementation: Update code requirements for construction of new buildings and substantive rehabilitations. Government can mandate cool walls in building codes or energy codes.

Considerations for Use: Cool walls are less effective in colder climates that have greater heating needs in the colder months. Cool walls are best suited to buildings with low roof-to-wall and window-to-wall ratios. Additional research is needed to evaluate effectiveness of cool walls in dense areas.

• Policy Levers: The mechanism municipalities can use to actualize the intervention. These policy levers will likely be used in combination with each other.
  
  
  MandateMandates are government regulations that require stakeholders to meet standards through building codes, ordinances, zoning policies, or other regulatory tools.
• 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).
  
  
  City planning processesIncludes city initiatives such as the development of climate action plan, pathway to zero-energy, master plan, transit plan, energy mapping etc.
  Introducing new or updated zoning/codesIncludes codes, zoning requirements or by-laws pertaining to urban planning and building construction activity.
• Intervention Type:
  Buildings and Built Form
• Sectors:
  Buildings

Impact:

• Target Beneficiaries:
  Property owners, 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

Implementation:

• Intervention Scale:
  Building
• Authority and Governance:
  City government
• Implementation Timeline:
  Medium-term (3-9 Years)
• Implementation Stakeholders:
  City government, Private developers, Property owners and managers
• Funding Sources:
  private investment, Public investment
• Capacity to Act:
  High

Benefits:

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