What is the "GREEN AREA FACTOR"?
The “Green area Factor" (GAF) provides an excellent opportunity to improve the city’s urban planning practices.
The objective of the GAF is to develop a practical tool for use by city planners that is based on research data, takes into account local characteristics and does not discriminate against low-budget projects by favouring expensive ecological solutions. Case studies, stakeholder events and surveys were used to ensure the functionality of the method. The method has been developed on the basis of existing green factor scoring methods while taking into account the climatic, ecological and legislative features and the wishes of those responsible for land-use planning.
The green factor method improves the city’s prerequisites for adapting to climate change by promoting the green efficiency of the vegetation on the plots and the conservation of sufficient green structure. Vegetation mitigates the risk of flooding, reserves carbon dioxide, cools down the heat islands of built environments, and increases the pleasantness and beneficial health-effects of the urban spaces.
In the green factor method, the planner sets a green factor target level for the plot that can be achieved flexibly by the garden designer using various green elements when designing the garden. The method developed for the City of Helsinki (Finnland) provides 43 different green elements relating to planted and maintained vegetation, various run-off water solutions and permeable surfaces, etc. The green factor is calculated as the ratio of the scored green area to lot area.
The green factor method has been developed to support the land use planning process, and it is intended particularly for city planners, landscape architects and garden designers. The green factor can, for example, be included in the zoning regulations or used for granting concessions during a construction permit application process. Similar green factor methods have been used with success in, among others, the cities of Berlin, Stokholm, Seattle and Toronto, as an important tool for maintaining and increasing the ecological and social advantages of green structures.