An increase in energy demand has contributed to the increase in the ‘heat island effect’, air pollution and flooding, resulting in unnecessary pressure on urban dwellers. It is for this reason that the EU’s Europe 2020 Strategy aims to reduce energy requirements by at least 20% by 2020. The Commission’s Energy Efficiency Plan 2011 identified buildings as having the greatest potential for energy savings. The plan focuses on mechanisms to reduce the energy requirements of existing buildings, in particular the role of public buildings in demonstration and dissemination projects.
Green roofs also have a role to play in rendering buildings more energy efficient. In Malta, however, the use and uptake of green roofs has been very low because of misconceptions around issues such as leaks. Information on the technology is sorely lacking. Although various green roof standards provide guidelines, the exact composition will be determined by the types of plants to be grown, the climatic conditions, weight loads and drainage requirements. Achieving a correct mix that addresses the requirements of climatic conditions is crucial to the success of a green roof. The Mediterranean climate is quite particular and plants native to the region could prove appropriate for use in green roofs. Most often the sedum species used are not native to the Mediterranean and as such sustain limited biodiversity. As a result native species for green roofs are a preferred option.
The LifeMedGreenRoof project aimed to construct two demonstration green roofs as case-studies: one on the University of Malta's Faculty for the Built Environment campus building and one on a building located on the campus of Fondazione Minoprio, a project partner, in Italy. They would be designed to demonstrate the benefits of green roofs for meeting environmental and biodiversity targets. The project also aimed to show that green roof technology is safe and cost efficient, reducing energy consumption thanks to the insulation properties of the system. Furthermore, green roofs reduce the risk of flooding through the ability to absorb water.
The LifeMedGreenRoof project represented a first major Maltese initiative to show the feasibility and benefits of green roofs. To this end it set up two demonstration green roofs: one in Italy and one in Malta. Initial efforts focused on identifying native plant species that are able to survive in a green roof environment. The plants selected were propagated and tested in green roof simulation beds to verify their compatibility with the exposed environment and with the substrate. Over 15 species of plants were eventually identified in both Italy and Malta. Given that soil is not an ideal growing medium on green roofs, studies were carried out of a range of components to be used as alternatives. An innovative material Biochar was selected to make up some of the substrates, owing in part to its ability to sequester carbon. The green roofs were then analysed to highlight their suitability for replication in a Mediterranean environment. Monitoring confirmed that native plants can be successfully grown on a green roof even when exposed to direct sunlight and wind. The project’s growing media can retain between 60% to 90% of the annual precipitation depending on the depth, the frequency and intensity of rainfalls. Furthermore, the presence of a green roof was shown to result in the reduced use of air-conditioners to cool the underlying rooms due to the insulation effect of the substrate and plants. They also keep the temperature of the roof slab and damp proof membrane stable especially during the hot summer season; in winter most of the plants can go without irrigation, while during the dry season irrigation need not be intensive. Another recorded benefit of the installation of the roofs is the creation of habitats for pollinator insects and other beneficial creatures including birds and butterflies. Moreover, green roofs help create pleasant environments for those with windows overlooking the roofs. The results of the project helped to draft two key documents: the Maltese standard for green roof construction, which provides professionals with information to ensure that green roof systems are planned, constructed and maintained in accordance with best practices and within the Maltese legal framework; and the green roof guidance document, which brought together all the findings of the project. The latter document proposes ways of integrating green roofs within national or regional policies and legislation. It was distributed to authorities, institutions, and government departments, which have an interest in the quality of the urban environment. A great number of individuals and institutions visited the green roofs and participated in the project's events. In this way, awareness was raised among stakeholders on the need to adopt green roofs within the urban areas. The long-term impact can be measured by the eventual uptake of the technology over a wide area and by the influence the project has on stakeholders in the coming years. Through the project it became clear that action must be carried out by local authorities to integrate the technology into the planning system and construction industry. The project contributes to the EU’s Energy Efficiency Plan 2011, the Directive 2010/31/EU on the energy performance of buildings and to climate adaptation as green roofs help reduce the heat island effect in urban areas. Further information on the project can be found in the project's layman report and After-LIFE Communication Plan (see "Read more" section).