Izgrađeno okruženje i rezilijentnost grada

Abstract

Rast populacije, koji uzrokuje neizbežno širenje gradova, klimatske promene i rastuća oskudica konvencionalnih izvora energije, fosilnih goriva, rezultuju pojavom raznovrsnih problema i poremećaja, što predstavlja izazove za razvoj principa i strategija kako urbanog planiranja tako i projektovanja i gradnje zgrada koji će pomoći našim gradovima da se suoče sa uticajima tih stresova. Za povećanje rezilijentnosti grada kroz projektovanje zgrada važna su dva pitanja: smanjenje potrošnje energije proizvedene iz fosilnih goriva i smanjenje zagađenja životne sredine. Veći kapacitet rezilijentnosti grada u budućnosti uključuje i postizanje energetske i ekološke bezbednosti, što podrazumeva razvoj tehnologija za korišćenje obnovljivih izvora energije i u skladu sa tim strategija kako za projektovanje i gradnju novih zgrada, tako i za energetsku sanaciju postojećih zgrada. U tom smislu u radu se navode strateški principi za projektovanje i izgradnju zgrada. Za ostvarenje energetski efikasnih zgrada omotač zgrade je najodgovorniji deo strukture zgrade. Osim zaštite od nepovoljnog vremena, osvetljenja i buke, komponente omotača zgrade dobijaju i ulogu proizvodnje energije. U radu se razmatraju inovativni koncepti i tehnologije materijalizacije omotača zgrada značajni za postizanje rezilijentnosti zgrada i time bezbednost životne sredine. Ukazuje se na projektantski koncept aktivnog odnosa zgrade i okruženja i u tom kontekstu razmatraju relevantne tehnologije i tehnička rešenja. Doprinos energetske sanacije zgrada rezilijentnosti grada pokazan je kroz diskusiju rezultata izvesnih prethodnih istraživanja. Pažnja je posvećena mogućnosti smanjenja potrošnje fosilnih goriva i zagađenja životne sredine, čime se doprinesi umanjenju klimatskih promena, što je jedan od aspekata postizanja urbane bezbednosti.

Cities are complex and dynamic structures that have existed for thousands of years despite many different influences and processes and resulting problems and disorders, which are the challenges that cities are continuously subjected to. In this sense, every city has its specific features, but nowadays, it is possible to distinguish several key processes with a continuously growing trend and related to: global population growth and migrations, intensive energy consumption in spite of decreasing availability of conventional energy sources, environmental pollution and climate change. For cities to be able to resist negative impacts of these processes in future, new and revised strategies for developing resilience of cities are needed. Scientific and professional circles consider a resilient city to be a city that has developed strategies and capacities to help absorb future shocks and stresses to its social, economic, and technical systems and infrastructures so as to still be able to maintain essentially the same functions, structures, systems, and identity (ResilientCity.org, 2016). The term resilience means the capacity of a system to absorb disturbance and reorganize while undergoing change so as to still retain essentially the same function, structure, identity, and feedbacks (The Resilience Alliance; Walker et al., 2004). Especially important is the ability to learn from the process of absorbing these disturbances – the ability to perceive the data and feedback on the results. This upgrades resilience of the system and helps to overcome disorders. When it comes to global population growth, according to projections the world population will continue to grow until at least 2050, with the population reaching 9 billion in 2040, and some predictions putting the population in 2050 as high as 11 billion (http://esa.un.org/unpp/wpp/). According to the United Nations Population Fund, 2008 marked the year when more than 50 percent of all people, 3.3 billion, lived in urban areas, a figure expected to rise to 70 percent by 2050 (UN, 2008).The same source indicates that in Europe 75 percent of the population already lives in urban areas, and predictions are that this number will reach 80 percent by 2020. In terms of resources of our planet, this increase in the number of population is considered unsustainable. Rapid population migration to cities leads to a dramatic expansion of cities, causing a large number of various disorders and problems which cities have to face, not only social, but also those that reflect the physical structure of the city, buildings and infrastructure, as well as identity. Given that the world’s existing building stock includes a large percentage of buildings that were built during the periods when energy consumption for the building operation was not the subject of substantial consideration, it is observed that it consumes a large amount of energy produced by conventional energy sources, fossil fuels. This problem increases due to intensive migration of population from rural and underdeveloped smaller urban areas to the cities, and because of intensive industrial development. From a global standpoint, cities consume between 60 and 80 percent of electrical energy and are responsible for large emissions of greenhouse gases (UN, 2008), especially carbon dioxide, which causes considerable environmental pollution, and climate change. Buildings and their supporting infrastructures are said to be responsible for emitting 50% of CO2 emissions, possibly rising to 70% if urban transportation is included (Jones et al., 2009). At a global level, if fossil fuels continue to be burnt at a ’business as usual’ trajectory, in a matter of a couple of decades, we will cross the 450 ppm level, taken as the limit for keeping global warming under 20°C (BBC, 2013; Jones, 2014). Assessments are that the production of fossil fuels globally will reach a maximum between 2010 and 2020, after which we are to face a decline in production and problems of exhausted sources of these fuels. This disorder has a direct impact on the growth of the price of these fuels, which can lead to complex problems. The aforementioned processes and associated disorders and problems affect the urban safety contributing to the complexity of the security issues. These issues and strategies for the achievement of the flexibility and resilience of cities can be considered from different aspects. In this paper, consideration is focused on the built environment, respectively buildings whose role and importance for achieving urban resilience are discussed. In this sense, the subjects of discussion are strategic commitments related to the principles of design and construction of buildings and the use of modern architectural technology. When it comes to increasing the resilience of the city through the design of buildings, the following two issues are important: reducing the consumption of energy produced from fossil fuels and environmental pollution. Increasing energy scarcity and climate change are recognized as key challenges affecting development of the principles and strategies of urban and building design which will help our cities to cope with the impacts of these stresses. The strategic guidelines for the design of buildings are one of the main factors to increase the resilience of the city. Solutions are expected with new technologies that use renewable energy sources and in strategies of controlled/rational consumption of energy. Overall, it is important to bear in mind that a resistant perspective acknowledges that change is constant and prediction difficult in a world that is complex and dynamic (Ward, 2007). The energy performance of a city’s infrastructure and building fabric is a key determinant of its capacity for resilience (Applegath, 2012). In the case of new buildings, technologies for conservation and energy production must be involved in their design from the very beginning, while the existing buildings need to be well thermally insulated in order to be suitable for the installation of infrastructure for the use of renewable energy sources such as solar collectors for water heating and photovoltaic modules. In this way, the buildings acquire the potential for reaching the category of zero energy buildings. Buildings have to be designed in such a way to enable new or existing urban structures transform in less energy-intensive and less carbon-intensive ones, instead of the current urban structures characterized by high energy consumption. In this sense, it is essential that buildings are more energy independent, and can produce enough energy for their needs or produce a greater amount that can be directed to cover certain needs of the community. Design approaches should be connected to the uniqueness of the geographical origin of the community, their tradition and national history, religious and social beliefs, so that the population can accept them. Architectural concepts that incorporate an active relationship between the building and its surroundings are resulting from the awareness of the complexity, dynamics and changeability of our environment. An active relationship between the building and its surroundings involves the implementation of the technologies of heating, cooling, ventilation and natural lighting that are based on the use of natural forces (such as the pressure differences, differences in temperature and humidity), and the use of renewable energy sources. Development of renewable energy technologies that can be incorporated in buildings, as well as architectural concepts and technology of zero energy buildings are crucial to increase the resilience capacity of cities and buildings in the future. In this paper, through a comparative analysis of case studies and the results of certain previous researches, relevant technologies and technical solutions are discussed and the importance of built environment, more exactly of buildings for achieving the resilience of the city is shown. Attention is paid to the possibilities of reducing fossil fuel consumption and pollution of the environment, thus contributing to reduction of climate change, which is one of the prerequisites if we want to achieve urban safety.