The report is based on both qualitative and quantitative data, for the first – theoretical – part of the report, majority of sources are books written about the topic of sustainable construction and its process together with statistics provided by Eurostat. The second part relies on facts and figures stated on official web pages of the HafenCity project based on assumption that it is the most reliable and up-todate source. I would like to thank my 5th semester professors for guide how to approach problem based report and mainly for organising study trip to Hamburg to see the development on our own. I would also like to thank my classmates and friends for providing valuable feedback. Most of all, I would like to thank VIA College University for providing perfect background for studying and library with inexhaustible number of information sources. The topic of the report “Sustainable refurbishment: theory and practice” is to analyse how are theoretical findings in the field of sustainable refurbishment applied in currently ongoing projects. The achieve that, the basic principles are specified, such as minimising energy consumption, providing barrier-free access or diversifying the area both socially and by function. In the second part, an example of area refurbishment is chosen.
The HafenCity project in Hamburg has been selected because of its huge scale and proclaimed concern about sustainability. Thanks to many precautions such as the HafenCity Ecolabel and strict rules for the competitive bidding, the project is mostly found exceptionally advanced in implementing sustainable solutions, with few exceptions lowering the high standard of the development. Keywords: refurbishment, sustainability, ecology, HafenCity, area conversion, Ecumenic Forum, Elbphilharmonie.
This report focuses on the concept of sustainable refurbishment of both single buildings and whole districts and its application in practice. The report is divided into two parts: first one focuses on the general idea and theory behind both sustainable construction and refurbishment, in the second part, examples of existing structures and areas are analysed to show in what extent is the theory used in new projects. Whole district refurbishment and area conversion is a key topic for many European cities, both because of their industrial past with unused outdated factories, power plants or harbours, and because of the hastily constructed housing blocks and whole districts according to the modernist urbanism.
Currently planned projects include conversion of the Battersea power plant and its surroundings in London (United Kingdom) to residential area with flats; development of large 200 ha district Nordhavnen, Copenhagen (Denmark), where part of the old port will be converted into another district of the growing Denmark’s capital; Les Groues, Paris (France), where 47 ha of old railroad system will be converted into residential and commercial property; or HafenCity project in Hamburg, 147 ha of outdated and almost unused harbour area directly adjacent to the city centre is being converted into new district, including residential and commercial areas, with schools, restaurants and sport facilities. The aim of the report is to answer the question how are the theoretical principles and findings applied in currently ongoing development projects.
As an example of applicating the rules of sustainable development on urban scale, HafenCity project in Hamburg has been chosen for the report. The refurbishment takes place next to existing city structure, close to the historical centre of an important European city and at the same time must deal with the current layout of the port area and high static and structural demands because of frequent flash floods and thick mud layer calling for special focus on the foundations. All these factors make the HafenCity development a challenging task. Another reason for choosing this project is the fact that the west part of the district has been completed, which makes it possible to evaluate the success of complying with the sustainability principles.
Sustainability – theory
Main section Housing and urban situation in Europe According to The 2011 Population and Housing Census, majority of dwellings in 28 EU countries has been built before the year 1980, precisely 66,4%. Out of this 44,1% has been built between 1946 – 1980. More precise statistic findings show that the dwelling construction in this time interval peaked before the year 1970I. As a conclusion, we can safely assume that approximately one half of dwellings in the European Union is 50 or more years old. After the World War II, there was an urgent need of fast construction and rebuilding the desolated European cities. The prefabricated construction was considered to be the best solution to satisfy the demand in as short amount of time as possible. The idea of changing the urbanistic approach using faster I Housing Statistics in the European Union 2010 report by the Federal Ministry of Science, Research and Economy of Austria construction made possible by prefabricated building parts was conceived earlier before war, but the mass construction started in 1950, with new districts and even cities being built.
In Czechoslovakia in year 1985, almost 99% of all new flat construction had been built as a prefabricated concrete panel block of flats. There is 45 million of these housing units in Europe, 34 million of which are located in the former Eastern bloc. The expected durability of the new prefabricated blocks of flats was 50 years, with shorter durability of thermal insulation, piping or windows – which makes majority of them not only obsolete, but close to end of projected lifespan, if not already over. II Especially in the Eastern block, e. g. Pripyat was supposed to be the ideal city according to then Sustainable refurbishment Definition of sustainability Sustainability is a broad term spanning a wide variety of approaches or aims. The most often used definition for the construction field is from the report of the United Nations Commission on Environment and Development (1987): “development which meets the needs of the present without compromising the ability of future generations to meet their own needs”. Sustainable development consists of three main parts: ecological sustainability, economical sustainability and social sustainability.
Ecological sustainability According to Eurostat dataIII, use of renewable energy in Europe is steadily on the rise, but still makes only around 12% of the total, as opposed to petroleum products (35%) or gas (22%). But even renewable energy production isn’t completely free of negative effects on the environment, which is why the primary aim is to reduce energy consumption overall. To achieve this, reducing the residential final energy consumption is crucial: its consumption is the second highest (25%) together with the industrial sector.
The economic benefit is related to ecological: as the resources of non-renewable energy grow thinner, their prices and thus energy price in general gets higher. According to the study of possibilities of refurbishment of high rise buildings in the EU written by the International Energy Agency, possible savings of heating energy for less efficient high rise building contemporary urbanistic views (it is mostly known as the ghost city after Chernobyl power plant disaster)
EUROSTAT statistics for final energy consumption in 28 EU countries (1990 – 2014) Even complete refurbishment can become economically beneficial after around 6 years only when the energy price is taken into the account – another gain would be from higher rents thanks to the better living conditions in the flats.
The most abstract of the three, social sustainability is focused on satisfying the needs of different people or social categories – based on income level, culture or age, for example – to enable beneficial interactions between these groups. Socially sustainable design implemented to building construction can vary from level-free access to including common meeting place for the local community or various accommodation prices to ensure social diversity as opposed to the uniformity caused by the block of flats, which somewhere led to forming of ghettos.
Application in construction process
The three main parts of sustainability can be further split for construction process into these aspects:
Prior to refurbishment, goals are set by the client to clearly state what he expects from the updated building. Based on it, architects collaborating with engineers prepare the refurbishment plan; how to achieve the goals by combining the principles with client’s demands. Technical solution includes using modern HVAC systems and possible use of renewable energy (demand for Renovation class 1 and 2 in Denmark), which is also positive for ecological dimension, but it should be calculated how advanced system should be used from economic point of view – what is the payback time. Architectural dimension should be closely connected with social dimension: the aim is to provide the best comfort of use for the users, preferably not only according to regulations, but through collaboration with users as well. Facade design is part of this dimension too, the best approach is to update the existing facade without destroying it completely. Cultural dimension represents local customs and norms which should be respected to maintain the continuity wanted for sustainable development.
The need of updating buildings to contemporary standard is clear, but there are two ways to achieve the goal. Either build from scratch – this can include the need to demolish the old – or renovate, refurbish. For calculating the environmental impact of the two alternatives, the Life-cycle assessment (LCA) methodology is used. The technique is used to calculate broader environmental influences and costs of construction, from demolishing and construction/refurbishment to the maintenance operation of the building. As an example of use in practice, a study Refurbishment or Replacement of Buildings – What is Best for the Climate? (2009) was used for the purposes of this report. The study was written on demand of Norwegian Bank “SpareBank 1 SMN” in order to decide whether to refurbish their headquarters in Trondheim or build new building for the purpose. “The comparison is based on calculations of greenhouse gases related to the phases Building construction (cradle to gate for building materials and components), Operation, Maintenance and Development during the life span of 60 years of the two alternatives.