Green Roof Policy - Copenhagen

In 2010, the city of Copenhagen, Denmark introduced a policy making it mandatory for new municipal buildings to have green roofs if roof slopes are less than 30 degrees. This policy applies to all types of buildings, from cycle shelters, schools and mixed used buildings to underground garages. The aim of the policy is to enhance climate resilience, urban biodiversity and the well-being of Copenhagen's citizens by reaping the benefits green roofs can provide, such as rainwater retention and heat absorption.

Overview

Type of instrument:

Legislative, regulatory and strategic instruments›Dedicated strategy, plan, or law

Challenges addressed

Water management (e.g. reuse)
Flood risk: pluvial and fluvial / soil permeability
Heat stress and heat island effect
Air quality
Social cohesion
Nature appropriation / stewardship
Reconnection to the biosphere / environmental education
Human health, comfort and well-being

Consideration of nature-based solutions:

Green roofs provide multiple ecological, social and climate benefits. They can absorb large quantities of rainwater in a sustainable way and can decrease temperature rises. They also create habitats for animals and plants while citizens can spend time on them to relax, socialize or plant vegetables. Green roofs have the potential to bring people together that live in a building or neighbourhood and thus can contribute to social cohesion when responsibilities for maintaining the roof are shared. The guideline requires that vegetation and soil be considered in the design of buildings and applies to all buildings with roofs that slope less than 30 degrees. The requirement applies to new buildings only.

Targeted (peri-)urban areas:

External building greens

Urban green space connected to grey infrastructure

Good practice characteristics:

Effective

Support multifunctional NBS

Sustainable in the long-term

Potential to be replicated / upscaled

Inclusivity

Governance

Government body/bodies

Initiating body:

City of Copenhagen, Environment and Technical Administration

Instrument design:

Details about how the instrument was designed:

A key impetus to systemically enhance green roofs in Copenhagen was provided by the city's participation in the World Green Roof Congress in London 2008. Cities from different continents attended the congress and exchanged ideas on the promotion of green roofs in their cities. The concrete idea to integrate green roofs into urban planning was developed by the City administration in light of the UNFCCC COP 15 in Copenhagen in 2009. In 2010, the city administration set out the ambition to become climate neutral by 2025 and transform Copenhagen into a green and innovative metropolis. After discussions within the city administration, this led to an agreement between the board of directors and the mayor to introduce a green roof policy in Copenhagen.

Instrument implementation:

Type of involvement:

The green roof policy foresees an active role of local communities in the implementation of green roofs. According to the policy, green roofs may become platforms for exchange between residents of all ages and origins. Detailed requirements for the characteristics of green roofs are lacking and thus, developers and owners can decide freely on parameters such as the roof's size, the type of habitat developed and the type of access to the roof.

Type of non-governmental actors involved:

Implementation of NBS (e.g. with government funds)

Targeted actors:

Public sector institution (e.g. school or hospital)

Private: household, real estate developer, business , financial

Citizens or community groups (CBOs), NGOs

Financing

Sources of funding:

Public local authority’s budget

Building owners' funds

Budget:

Unknown

Details about instrument financing:

The green roof policy does not foresee any financial support for the implementation of green roofs, and thus developers and owners need to fund implementation themselves.

Monitoring, evaluation and impacts

Achieved outcomes and impacts:

As of 2015, the City of Copenhagen has more than 40 green roofs. The policy enabled the construction of 200,000 square meter of green roofs in Copenhagen in only two years (2010–2011). Several examples of installed green roofs in the city are described in a dedicated brochure ( https://www.klimatilpasning.dk/media/631048/green_roofs_copenhagen.pdf ).

Success factors and lessons learned:

An important factor for establishing the policy was the external push provided by COP 15 that led to am ambitious agenda for climate action in Copenhagen. Making use of this window of opportunity and Strong leadership was key to realizing the green roof policy. Further incentives could be given by financial regulations that subsidize the installment of green roofs, also in those cases where it is not required by the policy. Furthermore, more specific guidelines on aspects such as species composition can enhance biodiversity and climate resilience benefits.

Sources and further information

References

List of references:

POCACITO (no date). Green-Roof programme. Copenhagen, Denmark. Available at: https://pocacito.eu/sites/default/files/GreenRoofs_Copenhagen_POCACITO.pdf (Accessed: 4 August 2022).

City of Copenhagen (2011). Copenhagen Climate Adaptation Plan. Available at: https://en.klimatilpasning.dk/media/568851/copenhagen_adaption_plan.pdf (Accessed: 4 August 2022).

Burszta-Adamiak, E., & Fiałkiewicz, W. (2019). A review of green roof incentives as motivators for the expansion of green infrastructure in European cities. Przegląd Naukowy Inżynieria i Kształtowanie Środowiska, 28.

City of Copenhagen (no date). Green Roofs Copenhagen. Available at: https://www.klimatilpasning.dk/media/631048/green_roofs_copenhagen.pdf (Accessed: 4 August 2022).

Photos

@CHUTTERSNAP en Unsplash