Overview:

Summary: Green walls are composed of plants installed on the sides of buildings. The plants cool buildings envelope temperatures and surrounding temperatures through evapotranspiration and shading. Green walls are also known as living walls or vertical gardens.

Implementation: Promote green walls by converting or intalling them on existing or new publicly-owned property.

Considerations for Use: Green walls require sufficient irrigation and high levels of ongoing maintenance. Plants should be selected that provide dense foliage to maximize coverage.

• Policy Levers:
  
  
  Lead by ExampleGovernments have ownership and jurisdiction over a range of assets (e.g. buildings and streets) and also serve as a direct employer, and contractor. This allows them to promote heat risk reduction and preparedness solutions and demonstrate their impact through leading by example with proactive interventions to make their assets, employment opportunities, and contracts heat-resilient.
• Trigger Points:
  
  
  Evaluating or initiating major city infrastructure projectsIncludes projects such as city transit, street or utilities construction / re-construction etc.
  Planned new developmentIncludes Greenfield or brownfield development or new construction
  Substantial rehabilitationIncludes the re-development or major renovation projects.
• Intervention Type:
  Green/natural Infrastructure
• Sectors:
  Buildings

Impact:

• Target Beneficiaries:
  Residents
• Phase of Impact:
  Risk reduction and mitigation
• Metrics:
  Decrease in building temperature, Energy savings, Number of installations completed and in progress projects, Stormwater runoff reduction

Case Studies:

• London's Living Roofs and Walls (C40 Urban Cooling)
• Bogota's Practical to Green roofs and vertical gardens (C40 Urban Cooling)
• Sydney's Green walls policy/design guide (C40 Urban Cooling)

Implementation:

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

Benefits:

• Cost-Benefit:
  High
• Public Good:
  Medium
• GHG Reduction:
  Medium
• Co-benefits (Climate/Environmental):
  Improve stormwater management, Preserve biodiversity, Reduce air and water pollution
• Co-benefits (Social):
  Build social cohesion, Improve human health, Increased property values, Save on utilities