Overview:

Summary: Green roofs cool the surrounding air and reduce building heat through a layer of vegetation or other plants. Green roofs can also serve as additional green space. There are two main types of green roofs: intensive and extensive.

Implementation: Incentivize installation of green walls through expedited permitting, tax credits, zoning bonuses, and stormwater credits or energy discounts.

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: The mechanism municipalities can use to actualize the intervention. These policy levers will likely be used in combination with each other.
  
  
  IncentiveFinancial and non-financial incentives to encourage stakeholders to implement heat risk reduction and preparedness solutions, including rebates, tax credits, expedited permitting, development/zoning bonuses, and more.
• 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:
  Green/natural Infrastructure
• Sectors:
  Buildings

Impact:

• Target Beneficiaries:
  Heat-vulnerable communities, Property owners, 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:

• Houston Downtown Management District Vertical Gardens Matching Grant (EPA, Pg 5)
• Bosco Verticale in Milan, Italy (UDF, Pg. 33)

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:
  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