Green Roofs and the Reuse of Collected Stormwater in Buildings - Essay Example

Green roofs and the reuse of collected storm water in buildings University Student Id Course Date Introduction The green roofs usually serve two functions which include being designed in a manner that can support the growth of different forms of the green vegetation on the top of established buildings. The second purpose which is served by the green roof is that they are also designed in a way which can support different forms of energy which are renewable and also support the collection of water hence assisting in supply of both water and also power to the individuals who are occupying the building (Chang, Rivera and Wanielista, 2011). However, even though the green roof is usually a single element for the building, it is of great significance which results from its long-term sustainability as well as their effects on the environment. In a similar way like the other cities which are found in Australia, Melbourne is usually faced with a lot of pressure which results from the urbanization. Moreover, the drastic growth of population, as well as the development of the urban areas, has led to the transformation of the natural environments into areas which have the well-engineered infrastructure (Oberndorfer, et al, 2007). However, the heat which is usually generated from the cars, commerce activities and also from industries together with the solar energy brings a lot of warmth in the environments of the city. Consequently, as a result of this high energy that is released to the environment, the health of the human beings are affected negatively. System description The transformation of the natural landscape into a constructed environment has resulted in large areas of land being paved hence creating various problems which include; vegetation loss, destruction of the natural habitats for the organisms, flash flooding and also high surface run-off. However, all these issues which are related to the transformation of the natural land have eventually resulted in various climatic changes. In addition, the issues have resulted in the environmental challenges, economic and also social challenges and therefore new ways are required to make the cities of Melbourne to be livable. Moreover, the majority of the cities in various parts of the world usually recognize the significance of establishing green infrastructure which comprises of the natural landscape assets such as the green spaces and also the water systems. Some of the green infrastructures usually includes; parks, trees, green roofs and also the water sensitive urban design such as the rain gardens as well as the wetlands. The environmental merits of having green roofs in the buildings are broadly recognized and some of them are; thermal insulation, producing renewable energy, reducing the surface run-off, collecting rain water and also improving the life span of roofing structure among the others. In addition, in each of the green roof, there are always components of series whose aim is to provide protection to the buildings, facilitate the growth of the vegetation and also helps in the collection of the rainwater. These series of the components include; drainage, waterproof membrane and also the root protection layer (Chang, Rivera and Wanielista, 2011). However, the green roofs are always very different from the rooftop gardens since they usually facilitate proven and also sustainable concepts. For instance, rooftop gardens are mostly an aesthetic feature for the established buildings whereas the green roofs mainly focus on minimizing the effect of the buildings on the environment in a way which is economical. The green roofs are usually established for many reasons such as adding value to the building property, assisting in the achievement of the environmental benefits which include the collection of the rainwater, building insulation and also improved diversity of the species. The vegetation which is usually found on the green roofs is always planted in a substrate which is growing that may have a depth which ranges between 50mm up to 1metre (Oberndorfer, et al, 2007). Importantly, in accordance with the tradition, the green roofs have been categorized into either extensive or to the intensive category. The extensive category comprises of the green roofs which are always lightweight and therefore have a shallow substrate layer of a depth of not more than 200mm hence they usually support low-growing vegetation species such as the succulents. However, on the other side, the intensive category usually comprises of the green roofs which require more irrigation as well as the maintenance as compared to the extensive green roofs. In addition, the intensive green roofs are in most cases well engineered and are always established on the structures which have great weight such as the car parks. Moreover, some of the terms which are used in describing the intensive green roofs include the roof gardens which are also known as the podium roofs. The roof garden is specifically used in the sites in which there is little space available for the growing substrate (Blackhurst, Hendrickson and Matthews, 2010). The main difference that exists is that the extensive green roofs were designed to be installed in the lightweight buildings whereas the intensive green roofs were designed for installation in the amenity spaces for individuals. Moreover, the international organizations of the green roof industry usually make use of these different classifications of the green roofs in the process of designing which kind of the green roofs are appropriate for a given building. The green roofs together with the walls are always appealing thus making a city to have green infrastructure since they can be added to the new buildings or even retrofitted on the already existing buildings. In addition, the green roofs are in most cases used as the compensation for the loss of greenery in the urban cities. Also, the green roofs usually provide cooling and also aesthetic improvements to the urban areas which are densely populated because there is no enough space which can accommodate other kinds of green infrastructure (Razzaghmanesh, Beecham and Kazemi, 2014). In the city of Melbourne, the number of the green walls is almost 50 the green roofs are usually more than 100 while the number of the green facades are around 100. However, there is actually very little information in Australia concerning how the green infrastructures can be created and also managed. Main design issues Maintenance is among the key issues that need to be considered in the designing phase of the green roofs. The designing of a green roof has to incorporate a proper understanding of how the system can be maintained. The system has to be properly maintained to ensure it functions well and achieve the set objective. The property owns and the building owns are expected to be aware of the ways that can be used in maintaining the green roofs and must have the necessary commitment to ensure proper maintenance. The systems developed are expected not exceed the resources, skills, and resources of the people who are given the responsibility of maintaining the system. There are some green roofs in Melbourne that are designed in a way that they require horticultural management that is complex (Blackhurst, Hendrickson and Matthews, 2010). This makes it essential to make sure that the management contracts employees with specialist expertise in managing the green roofs making the landscapes start deteriorating. The poor management of green roofs can lead to complaints among the users hence creating the need to prematurely replace the asset. The replacements can be aimed at achieving green roof management that is sustainable and efficient both environmentally and economically. The provider of a green roof can be best placed to provide on-going maintenance using contracts. Therefore, the person responsible for ensuring proper maintenance of the green roof is expected to be clear concerning the objectives and the capacity (Chang, Rivera and Wanielista, 2011). However, all the designing options have to be fully evaluated to make sure that the maintenance entailing them is known hence selecting the design that can ensure better maintenance. The other key design issue is costs of the ongoing maintaining of the green roof. The on-going maintenance costs associated with the designing of the green roofs from the point of asset owner and the client view. In the process of determining the costs associated with maintaining the green roofs has to consider engaging the contractors and consultants who have the relevant experience in the maintenance. The advice can be provided while considering the resource that is needed in the process of maintaining the materials that can be used in the maintenance process. For the commercial projects that are large, the maintenance effect statement can be easily and efficiently provided by landscape designers. Alternatively, the maintenance objectives can be specified during the designing process where the designer is expected to put into consideration in the designing process. Some considerations can also be needed for ensuring the renewal of the green roofs and walls, especially where there are short term installations. There are some cases where the green roofs are expensive to maintain they can be dismantled to install a new one that is cost efficient in maintaining (Razzaghmanesh, Beecham and Kazemi, 2014). In many cases, green roofs have been designed temporary with the aim of creating the necessary opportunities for renewing but such consideration ha to be made during the designing phase of the green roofs. Planning permit from the local council is also required in the process of designing green roof. However, currently there are no specific guidelines that are needed in the planning of the green roofs in Melbourne, but the designing has to acquire the necessary planning permit. Such works that require planning permit can include building new structures and replacing the roof that has been in existence. The other designing issues that need to be considered can include the siting controls like overlooking, setback requirements and shadowing where height controls apply as rooftop structures can sometimes be prohibited (Bianchini and Hewage, 2012). For instance, green roofs are being used in meeting the space requirements in the private open spaces in the private dwellings. Building permits are usually issued while following the building regulations in Melbourne. Despite the fact that there are no particular requirements that are related to the building regulations, some aspects like drainage, safety, performance standards among others need to be considered in the designing phase. Application to building in CBD of Melbourne Green roofing and reusing of the collected storm water in the building can be applied in the Melbourne CBD. The green roofing can be applied to ensure efficiency in the use of energy through reducing winter heating costs and the costs used in cooling during summer through ensuring insulation of the buildings to reduce heat loss. Besides, reducing the heat loss green roofs results in a reduction in the levels of noise and enhance the sense of well-being through the use of the aesthetic plant value. The buildings in the Melbourne CBD can make use of the green roofs and reuse of the collected storm water is used in the process of reducing storm water runoff. Reducing the storm water volumes has been considered as a benefit because the expansive areas of the impervious surfaces are creating the challenge of localized flooding at times of heavy rains (Oberndorfer, et al, 2007). Therefore, the reuse of the storm water collected can be a solution to the localized flooding during the heavy rains. Besides, the green roofs can be applied in the CBD of Melbourne to help in the process of mitigating urban heating hence essential in cooling through evapotranspiration reducing the energy demand. Green roofs and reusing of the collected storm water in buildings can be applied in the CBD buildings in Melbourne to increase the quality of the storm water runoff hence reducing the effects on the aquatic ecosystems. The roof runoff can be reduced and slowed by the green roofs by acting as the sponge. However, the hydrological performance of the green roofs largely depends on many variables that can include drainage layer design, roof slope, and composition. The buildings in the Melbourne CBD can make use of hydrological models in the process of assessing the runoff reduction that can be achieved through the use of green roofs (Razzaghmanesh, Beecham and Kazemi, 2014). Adapting the hydrological models in Melbourne CBD buildings can be appropriate in the process of providing the technical information that can be of help in the process of designing the necessary green roofs that can help in ensuring efficiency in energy use and reduce the negative effects of runoff water on the ecosystem. References Bianchini, F. and Hewage, K., 2012. How “green” are the green roofs? Lifecycle analysis of green roof materials. Building and Environment, 48, pp.57-65. Blackhurst, M., Hendrickson, C. and Matthews, H.S., 2010. Cost-effectiveness of green roofs. Journal of Architectural Engineering, 16(4), pp.136-143. Chang, N.B., Rivera, B.J. and Wanielista, M.P., 2011. Optimal design for water conservation and energy savings using green roofs in a green building under mixed uncertainties. Journal of Cleaner Production, 19(11), pp.1180-1188. Oberndorfer, E., Lundholm, J., Bass, B., Coffman, R.R., Doshi, H., Dunnett, N., Gaffin, S., Köhler, M., Liu, K.K. and Rowe, B., 2007. Green roofs as urban ecosystems: ecological structures, functions, and services. BioScience, 57(10), pp.823-833. Razzaghmanesh, M., Beecham, S. and Kazemi, F., 2014. Impact of green roofs on stormwater quality in a South Australian urban environment. Science of the Total Environment, 470, pp.651-659. Read More