The European green deal, and the recently approved “Green Renovation wave” form part of the European Commission’s strategy to combat the economic crisis caused by Covid-19. These include a focus on green roofs and vertical gardens which are also part of Europe’s overall efforts to embrace decarbonisation, drive energy saving and combat energy poverty.

This excellent initiative will enable cities to benefit from the immense ecosystem services that roofs and vertical gardens can bring, in particular:

• Improved rainwater retention capacity which reduces flooding problems during peaks of precipitation
• An improvement in the microclimate and consequent reduction of the heat island effect
• Better air quality, through the capture of CO2, the production of oxygen, and the retention of dust and particles suspended in the air
• Decreased noise
• The promotion of biodiversity
• A reduction in energy costs, and energy poverty, due to the thermal insulation the green roofs provide to buildings
• A reduction in building maintenance costs by protecting and increasing the life expectancy of waterproofing
• The possibility of producing fresh local food
• An increase in useful space in the city, and
• An increase in real estate values.

If all buildings have a roof, the question is, why do we still have millions of square meters of roofs in cities that bring no benefits to residents? The Portuguese government has now come into alignment with wider European thinking, and the recently established environmental fund provides financial incentives for the installation of facades and green roofs.

The green roof market has been growing in Portugal for the last years. However, the spread of green roofs, initially in Europe and later around the world, has only been possible due to the adoption of various incentive policies promoting their construction, based on research findings supporting their environmental, economic, and social benefits. Without political will, it will be difficult for green roofs to be built on a large scale in cities, and without large-scale implementation the benefits to the urban environment will not be significant.

The Porto Fifth Façade Project (PQAP), developed by the Portuguese association for green roofs, ANCV, along with Porto’s municipality, is a very good example of how local authorities can help to drive a change in attitude to how buildings should serve people. This year long project was designed to identify which models the municipality of Porto should follow in order to embrace green roofs into the urban planning, environmental and climate change strategy of the city. The municipality enthusiastically backed the project, and the co-operation between ANCV is an example of a successful case study.

One of the most important parts of the project related to the performance of the green roof in the development of the policy proposal.

For many years, the focus in Europe had been on creating incentive policies but these invariably did not distinguish between the different types of green roofs available. The lens should now be sharply focused on what kind of green roofs we want in our cities, taking into consideration the services they can offer and each city’s different environmental needs. Policies should reflect each city’s individual needs and should, on a case-by-case basis, detail which characteristics and benefits are needed to meet their specific needs.