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14:00   ENHR - Workshop Sustainable transformation
Chair: Anke van Hal
System-search IMPROVING THE DESIGN OF ADAPTABLE BUILDINGS THOUGH EFFECTIVE FEEDBACK IN USE
Graham Kelly, Rob Schmidt, Andrew Dainty, Vicky Story
Abstract: For many years the issue of how to design buildings which can adapt to changing demands has posed a considerable challenge. This debate has had renewed significance given the emergence of the sustainability agenda and the need to extract additional value from built assets through life. Developing a better understanding of how buildings change over time is arguably crucial to informing architects concerned with extending the life of buildings. This paper critically reviews literature on adaptability, together with that relating to knowledge feedback and architectural practice, in order to construct a theoretical platform for understanding how knowledge of how buildings change can be used to inform design decisions. A pilot case study is used to illustrate the ways in which buildings change could be captured to inform adaptable designs in the future. The work reveals a lack of knowledge in how buildings change and how, if this was fed back to architects, it could support design decisions that might increase the life of many buildings.
System-search DRIVING SUSTAINABLE INNOVATION IN CONSTRUCTION COMPANIES
Christian Thuesen, Christian Koch
Abstract: By adopting a theoretical framework from strategic niche management research (SNM) this paper presents an analysis of the innovation system of the Danish Construction industry. Theories within SNM look upon innovation in a sector as a socio-technical phenomenon and identify three levels of socio-technical interaction within which sectorial innovation can be explained. The analysis shows a multifaceted landscape of innovation around an existing regime, built in the existing ways of working and developed over generations. The regime is challenged from various niches and the socio-technical landscape through trends as globalization. Three niches (Lean Construction, BIM and System Deliveries) are subject to a detailed analysis showing partly incompatible rationales and various degrees of innovation potential. Based on the analysis, the paper further explores how companies can be introduced as drivers for innovation in the construction industry. By bridging SNM with business development activities through an adapted version of Ansoffs growth matrix, companies continuously and consciously can develop a competitive advantage by targeting new and existing markets with new or existing competencies/niches. The paper concludes with a discussion of how this approach can help to solve the challenge of retrofitting the existing building stock and thereby enabling the development a low energy consuming society.
System-search EXPLORING ROBUSTNESS OF ENERGY PERFORMANCE OF DWELLINGS TO OCCUPANT BEHAVIOUR: RENOVATION AND POST OCCUPANCY
Merve Bedir, Gulsu Ulukavak Harputlugil, Laure Itard
Abstract: In this paper, we focus on the influence of occupant behaviour on the energy performance of dwellings, before and after renovation process. In this context, ‘ventilation control pattern’, ‘maintenance’, and ‘heating energy demand’ are selected as the key parameters of the study. The aim is to reveal the sensitivity of energy performance of a dwelling to occupant behaviour, considering the pre and post-renovation process. Sensitivity of dwelling energy performance to occupant behaviour is analysed using Monte Carlo method. This method is one of the most commonly used methods to analyze the approximate distribution of possible results on the basis of probabilistic inputs. The inputs are selected as: window and grid operation, and mechanical ventilation set for ventilation control. The data used about occupant behaviour is gathered from OTB Survey [2008]. The Dutch reference building is used as a generic building to test the behavioural patterns. The result shows that a renovated [maintenance] dwelling is more robust to ventilation behaviour of the occupant.
System-search BETWEEN MARKETING AND FINANCIAL SUPPORT: DUTCH MUNICIPAL POLICY INSTRUMENTS TO IMPROVE THE QUALITY OF PRIVATE HOUSING STOCK
Milly Tambach, Frits Meijer, Henk Visscher
Abstract: Dutch municipalities are faced with an ageing private housing stock, of which parts show a diversity of quality backlogs, including their energy quality. Dutch municipalities are in the process of developing a combination of communicative and economic policy instruments to seduce private homeowners to invest in their dwellings’ quality. Homeowners’ willingness and capability to invest, and their level of organization play key roles here. This paper investigates, if the applied policy instruments to improve the quality of private housing stock in three Dutch municipalities are effective as well as cost-effective for both municipal governments and private homeowners. First results indicate that municipalities are marketing quality improvements to private homeowners by organizations that support and communicate with homeowners, but yet it seems without the hoped-for large-scale improvements. A multi-level policy approach seems to be needed for private dwelling improvement to become successful. This implies an improved playing field shaped by the national government, in which municipalities can make use of their local long-term oriented economic policy instruments more efficiently, such as property taxes and rebates on such taxes for (e.g. energy) quality improvements.
System-search UPGRADE OR REPLACE? Obsolescence and its influence on demolition decisions from a sustainable viewpoint.
Andre Thomsen, Kees van der Flier
Abstract: What is better: improvement or replacement by new construction? The choice between life cycle extension or replacement of existing buildings is at itself a vital but very difficult decision, involving a wide range of different aspects and affecting several contrary and often conflicting interests. In the past decade we studied the decision making on demolition in the Netherlands. Based on the available literature and statistical data we analysed the actual practice in the Netherlands and built a conceptual framework for further comparative and case study research. In addition to this research we placed the choice between improvement and replacement in a sustainable context, made an inventory of existing literature about comparative findings, analysed the outcomes and compared them with our own findings. Overlooking the results so far we concluded that life cycle extension by renovation and reuse of existing stock is generally more sustainable, more effective and more efficient as replacement by new construction. As an often used demolition motive, obsolescence is a vital but complicated variable. Our paper describes its meaning, discusses its influence on the decision making about demolition from a sustainable viewpoint and concludes with recommendations for property management and the decision-making process. Since research references on demolition are scarce and empirical sources rare, the paper has inevitably an explorative character.
System-search ARE OPEN BUILDING PRINCIPLES RELEVANT IN THE SOUTH AFRICAN HOUSING SECTOR? CSIR INVESTIGATIONS AND ANALYSIS OF HOUSING CASE STUDIES FOR SUSTAINABLE BUILDING TRANSFORMATION
Amira Osman, Pieter Herthogs, Calayde Davey
Abstract: The CSIR Housing Research Group in collaboration with a number of partners has been investigating the concepts of sustainable building transformation in the South African housing sector. Documents such as Medium Density Mixed Housing: sustainable design and construction of South African Social Housing (Osman and Herthogs, 2010); Environments of change: a design solution for an informal settlement in Mamelodi (Gottsmann and Osman, 2010); “Time” as a key factor in design and technical decision-making: concepts of accessibility, affordability, participation, choice, variety and change in the South African housing sector (Osman and Sebake, 2010) are products of these investigations. These studies have relied heavily on a number of theories, including Habraken’s Supports, Open Building levels, and different approaches to material/component re-use. All of these theories provide approaches with regards to the way in which materials, building components and the buildings themselves are re used or salvaged, based on life cycle analysis. However, it has been noticed in previous studies that uniform definitions for this research field are lacking and many researchers work in small enclaves and do not communicate enough with each other. There are numerous terms used to describe this approach to the design of the built environment and these are sometimes confusingly interchanged. Thus, this paper presents specific working definitions and then proceeds to carry this investigation further by analysing housing case studies with regards to sustainable building transformation. In this process it is attempted to assess if the theories are relevant and applicable in the South African context. While it is acknowledged that these approaches to design and delivery need to be considered for the whole housing market, there is a pressing challenge to government to deliver low-cost and affordable housing. We therefore saw it as important to try and influence thinking, design and planned delivery approaches at the conceptual stages before future projects proceed in the typical manner which we perceive to be unsustainable. To demonstrate the above the selected case studies are the K206, Alexandra and Elengeni, both in Johannesburg as well as the Potter’s House development in central Pretoria. The criteria for project selection will be explained and a checklist for assessment with regards to adaptability will be presented. The capacity for sustainable building transformation will be rationally assessed by studying the internal planning, construction methods, material selection and detailing. The paper will conclude with recommendations for new projects as well as the possibility for incorporating adaptable features in existing projects.
System-search CONFLICTING FLEXIBILITY
Peter de Jong, Aart Schaap
Abstract: New buildings are designed for its first users. For a sustainable approach there are many advantages in designing in flexibility and adjustability in order to enable and facilitate the other sequential users. For the first investor this flexibility is translated into improved exit values due to increased potential. The second investor is acquiring a building with multi-functional opportunities. The politically stimulated combination of schools with day care is generating several new design commissions in the Netherlands lately. These projects are characterised by a high level of user related features. At the same time these kind of buildings are confronted with an additional need for flexibility due to (demographic) developments in the neighbourhood. There are some good examples of such projects, but there is a distinguished need for additional workable solutions. One of the design projects of the faculty of Architecture started research by design to establish an architectural approach for the combination of elementary schools with after-school child care in different scenarios: transformation of an existing building in a shrinking village, as a replacement in a urban setting and as a new addition to an existing school in an area with growing potential. The combination of scenarios strongly suggest a focus on flexibility during the building’s life time. The growing area will create a peak demand, so even if it does not become a shrinking city after a while, the combined school will still have a fluctuating capacity need. However in the research by design, executed by architectural students, it can be observed that not the life time flexibility, but the daily flexibility, needed by the combination, takes all the creativity. It is already too complex to create multifunctional spaces to be used for learning zones in day time and play area and child care zones afterwards. Compared to other types of projects, the first user approach related to architectural design is in this function mix getting even more attention with the specific requirements, up to the level of dedicated furniture. The solutions provided by practice for the life time flexibility are in many cases related to an even more complex function mix. If a new neighbourhood first can be characterised by a peak in delivery, followed by baby care, elementary school and child care, higher education and taking care of the elderly people afterwards, the relation with different care functions becomes more obvious and time related. The synergy between those functions can be very promising in the right combination. Such a view on the neighbourhood suggests social centres developing and changing over time together with their servicing area. The context will lead to certain investors willing to fulfil their social and sustainable ambitions. The research by design itself will have a satisfactory result for the institutions dealing with the implementation of after-school child care if the proper selection of design suggestions are produced. These institutions will represent the first users. The scientific and social significance will be in the developments clearing the conflict by giving an answer to both the daily as well as the life time flexibility.
System-search IMPACT OF PUBLIC SUBSIDIES ON HOUSEHOLD INVESTMENT DECISION IN ENERGY EFFICIENCY ACTIONS
Sylvain Laurenceau, Celine Varenio
Abstract: Buildings are responsible for over 30% of carbon dioxide emission in the world. This sector has the largest potential in reduction of energy use demand and CO2 emissions among the IPCC sectors. Besides, rational actors in this sector should have a higher activity as some measures are cost effective, i.e. bills savings stemming from the reduction of energy use over equipments lifetimes are more important than the cost of the measures. In the framework of their climate policy, it is in the interest of public authorities to implement cost effective measures and stimulate investment in energy efficiency actions for housing. The issue is to merge public aims in the reduction of CO2 emissions on a given territory and household private interest in reducing their energy bill. In theory, households hold interest to invest of efficiency energy of their houses, because of comfort improvement and bill cuts. However, in practice and in spite of public financial help, the diffusion of these measures is limited. How subsidies spur households to implement energy efficiency measures in their housing and which are the main barriers to its implementation? This paper provides answers to these questions, presenting the results of an analysis about the energy efficiency measures pay off (like wall insulation or the installation of a new boiler) with, then without, public subsidies and analyzing with a case study the barriers that prevent households to implement energy saving actions despite their economic interest. The study will be based on the potential reduction in CO2 emissions of Grenoble urban area in France. Based on the economic literature, the first part of the paper presents household’s investment decision and assesses the potential cuts in CO2 emissions. The segmentation of Grenoble urban area housing sector based on the type of building, its size, age, heating system, and use gives us a sharp view of the cost and potentialities of CO2 emission cuts and energy saving in this area. Then the household’s investment decision and the analysis of public policies targeting energy efficiency provide the equilibrium in this pure, unbiased, rational world. The second part, based on the empirical study, provides analysis on investment decision when transactions costs, information asymmetries and liquidity constraints are taken into account. This part tries to explain the differences between the equilibrium previously described and reality, and value the potentiality of CO2 emission cuts if biases were removed. The paper concludes that public subsidies allow reducing payback period, but payoff improvement is not enough to encourage households as a whole to implement measures. Even if, thanks to public subsidies, payback is made sufficiently attractive to force investment of rational households with a high actualization rate, a large part of households are still not investing in energy efficiency actions. Besides, even if economic pressure plays a role, households do not ever choose the best payoff. For example they may prefer to replace windows whereas this solution is not cost effective. Informational asymmetry, transaction costs, liquidity constraints tend to explain households choices. This paper provides a methodology to assess potential of CO2 emission cuts and energy savings in the housing sector in a given area. Besides, it estimates the amount of money public authorities could spend to remove biases according to the amount of money they spend on payoff improvement and on the price they value the potential of CO2 emission cuts and energy savings in the considered housing sector.
System-search APPROACHES TOWARDS A SMART & SPEEDY IMPROVEMENT OF THE IN SERIES DEVELOPED POST WAR HOUSING STOCK
Anke van Hal, Leonie van der Steen, Eefje van der Werf
Abstract: One third of the current housing stock in The Netherlands dates from the sixties and seventies and a large part of these dwellings are fairly similar (because they were built in series). There is a high need for smart and speedy renovation methods, to improve technical, energy and cost efficiency of renovation projects as well as to limit inconveniences to residents. A considerable number of professionals in the Netherlands currently are making a combined effort to improve these methods and their implementation, in an initiative called Smart & Speedy (‘Slim & Snel’ in Dutch). This article describes this initiative, some results till now and an inspiring already realized renovation project that illustrates the goal of the Smart & Speedy approach.