PROJECT DESCRIPTION
BACKGROUND
Along with the spread of large cities, green areas are reducing in size and are becoming fewer in total. The interest in making use of the unused surface areas of roofs for green space has increased in recent years. A green area can be created on a roof as a roof garden. A relatively new and interesting alternative to high maintenance roof gardens is the so-called extensive green roof i.e. those with a growing medium of six inches (150 millimeters) or shallower. In recent years development of thinner and lighter earth layers has been achieved making it possible to green large roof areas, such as industrial buildings, with light allowable roof loadings.
OBJECTIVES
The goal of the 'Extensive Roof Greening' project was to achieve a wider application of an innovative roof greening technique throughout Scandinavia through demonstration and dissemination of associated environmental benefits. An easily accessible facility, with around 9500m2 of industrial roofing laid with 'lightweight green roofing' of different types, was anticipated to promote increased use of the technique and lead to an improved city and industrial environment and lower energy consumption. The action plan included the following steps: - Detailed planning and best practise study - Detailed engineering design - Roof reparation/sealing/platform construction - Construction of green roofing elements - Seminar centre fit-out - Quality control and auditing - Experimentation and academic reporting. The project was to represent a pollution prevention approach with respect to water and energy management. The key aspect for storm water control was to be reduction at the source. From an energy conservation viewpoint, green roofs apply a combination of well proven insulation improvement and a novel use of the natural cooling effect of evaporation and transpiration.
RESULTS
The project may be regarded as a technical success. The overall aims involved in the construction of the demonstration facility for green roof installations have been completed. The sustainability of such roofs in the Scandinavian climate conditions has been verified. Research work has been completed and other work is still in the initial stages, confirming the various environmental benefits of the green roof installations. Expectations prior to carrying out the project have been met: - Green roofs ensure considerable reduction of the storm water run-off. The system is anticipated to serve an important storm water management role by markedly decreasing storm water flow peaks and reducing problems of local flooding. Green roofs provide a significant water regulation effect during rainfall events. Up to 60 % of the yearly precipitation can be managed in-situ and returned to the atmospheric hydrological cycle through evaporation and transportation. - Significant energy savings for heating can be achieved. Extensive green roofing is anticipated to reduce the overall energy consumption of the buildings through improvement of the roof’s thermal insulation and provision of active summer cooling through evaporation and transpiration effects. - Wider biodiversity in urban environment can be achieved. The green roofs have the potential to increase biodiversity and reduce noise in the area. Local residents may find the industrial park more appealing when seeing green roofs instead of cold industrial buildings. The botanical roof gardens have proven to be of interest both on the national and international scales with specific emphasis on the sustainable development of urban areas. Roof greening is in addition anticipated to extend the useful life of the roof providing for material and cost savings in roof maintenance or replacement. The project has a very high potential for demonstration. The Visitors centre which was established and opened during the project was still operational after the project ended. The green roof area of 9 500 square meters is still maintained by the beneficiary and is expected to last for several decades. A number of postgraduate students and doctoral researchers have based their research papers on the topic of green roofs. The research papers will be published on the project website, subject to the consent of their authors. The continuity of the project has been ensured by the establishment of the Green Roof Institute and a conference on “Biological strategies for sustainable cities” is planned for October 2004. . A follow-up report was carried out in 2005 by the LIFE external monitoring team. It showed that the centre remains an important visitor attraction and that the project website, published in seven languages, remains open at: http://www.greenroof.se/. This project has been selected as one of the 24 "Best" LIFE Environment projects in 2004-2005
