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 roofs through expedited permitting, tax credits, zoning bonuses, and stormwater credits or energy discounts.
Considerations for Use: Green roofs need sufficient structural support and do not work on steep-sloped roofs. Green roofs require maintenance and upkeep every year. Roofs that are open to the public require safety precautions. Intensive green roofs provide more co-benefits (such as stormwater management) are much heavier than extensive roofs and require more structural support, irrigation, and fertilization as well as additional maintenance. Green roofs are generally more feasible and cost-effective in new construction versus retrofits. Given the costs required to install and maintain green roofs, requirements to install them must be carefully considered.
- 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:
- Target Beneficiaries:
Residents; Property owners; Heat-vulnerable communities
- Phase of Impact:
Risk reduction and mitigation
- Portland FAR vegetated Roofs (GCCA, Pg 48)
- Toronto Eco-Roof Incentive (ULI, Pg 54)
- Singapore LUSH policy (C40 Urban Cooling)
- Intervention Scale:
- Authority and Governance:
- Implementation Timeline:
Medium-term (3-9 Years)
- Implementation Stakeholders:
- Funding Sources:
Public investment; Private investment; Grants and philanthropy
- Capacity to Act:
- Public Good:
- GHG Reduction:
- Co-benefits (Climate/Environmental):
Improve stormwater management; Preserve biodiversity; Reduce air and water pollution
- Co-benefits (Social):
Save on utilities; Increased property values; Build social cohesion; Improve human health