Building: LCM Tools for Green and Sustainable Buildings
Time: Monday, 29/Aug/2011: 2:00pm - 4:00pm
Session Chair: Allan Astrup Jensen
Session Chair: Arpad Horvath
Location: Room 3
1st floor


Challenges for sustainability innovations in real estate and construction industry

Juho-Kusti Kajander1, Matti Sivunen2, Jukka Heinonen1, Seppo Junnila1

1Aalto University, Finland; 2Boost Brothers Inc, Finland

The climate change mitigation is one of the greatest challenges of sustainable society. Climate mitigation has boosted the fastest growing new investment market in the world with over 140 billion dollars yearly investments. Inside the market, the built environment is assessed to offer a wide scope of opportunities for cost effective sustainability business innovations. Paradoxically, the sustainability opportunity has not considerably accelerated innovation production in the real estate and construction (REC) industry. In fact, most new sustainability innovations in built environment seem to come from other industries. The latest research suggests that there is little innovation activity in REC industry, and most of the occurring sustainability innovation projects would seem to use traditional R&D processes, which is often unsuitable for fast customer-oriented radical innovations that are expected at the moment in sustainability markets.

The study was set to investigate what are the challenges of sustainability business innovations in built environment and how do they differ from the challenges of other cleantech sector innovation and general innovation. Some ninety sustainability innovation projects were scanned through, and further several professionals from public funding organizations, venture capital, academia and REC industry were interviewed to increase the understanding of challenges specific to sustainability innovation in built environment.

Interestingly, the results imply that the sustainability innovations in built environment have several unique challenges. In effect, it would seem that the challenges in sustainability innovation in built environment differ from other cleantech innovation as well as general innovation theories. The distinctive characteristics for REC were found to be the role of regulation as the main driver and barrier, longer value chain decision-making mechanisms, REC industry’s project-business orientation, lack of innovation processes and competencies, and the aggressive use of sustainability certificates in marketing. In the future, the sustainable business model development in the built environment should focus more on the internal innovation process and ensure that all the essential components of successful innovations are in place.

Determining the environmental influence of energy generating components for façade integration within existing high-rise buildings by means of LCA

Katrin Lenz, Michael Held, Sarah Schneider, Klaus Sedlbauer

University of Stuttgart, Germany

The amendment of the Energy Performances of Buildings Directive (EPBD) from 2010 stipulates the use of renewable energies for improving the overall energy efficiency of new built and existing buildings within the European Union. In this way, the Directive encourages the reduced use of fossil resources from an environmental point of view. Furthermore, economic considerations like the determination of cost optimum levels for defining minimum requirements for the overall energy efficiency are implemented as new aspects.

The EU funded project “Cost-Effective” addresses energy, environmental and economic related aspects of the Directive indirectly with focus on the existing European high-rise building stock. As high-rise buildings offer very large areas especially for exterior walls, five new energy generating façade components are being developed to supply such buildings for non-residential use, with thermal energy or electricity which is produced from renewable sources. Beneath showing the potential of a reduced use of fossil energy for building services, the project aims also at setting up cost-effective and environmental beneficial solutions for the integration of the components.

The environmental influence of the new developed components is determined by means of Life Cycle Assessment (LCA). The assessment includes their whole life cycle as well as respective potential target buildings for application. As the components are expected to have a significant influence on the environmental building performance especially within the operation phase of the building, the assessment focuses on the special use of the component for e.g. heating, cooling and ventilation purpose. The basic principles for conducting the LCA of the newly developed components and preliminary results will be presented with regard to the components environmental influence within the use phase of a building.

The energy and environmental implications of construction in China

Yuan Chang, Robert Ries

University of Florida, United States of America

Building and infrastructure construction has been an important sector in China since the economy began accelerating in the previous decade. Energy use in the construction sector in China represents over one quarter of total national energy consumption as well as related environmental emissions. Projections for future building and infrastructure needs indicate that construction activity will remain at a high level for the foreseeable future. China has also set national goals for economic growth and future energy use and environmental emissions per unit of gross domestic product (GDP).

An input-output life cycle assessment model of the Chinese economy coupled with a process-based life cycle assessment model was used to estimate the energy use and related environmental emissions from the construction sector. This approach was used for the evaluation of both the embodied energy of the construction sector in China as well as the life cycle energy impacts of constructed facilities. The construction sector and building operation were found to have a significant share of national energy use and environmental emissions.

The models were also used to examine the possible future energy scenarios in building construction given stated policy and prospects for economic development. Future expectations and targets for energy efficiency, projections of building and infrastructure construction, and the expected continuation of increases in urbanization and quality of life were used to examine the life cycle energy use of urban and rural residential buildings including construction, operation, and demolition.

The model results indicate that both energy sources and end uses will shift in the future, and that meeting targets for energy use will be challenging without new policies that address improvements in manufacturing and building operations. Meeting the future national goals will require not only that building related energy use for appliances, heating, and cooling is improved but also that the building and infrastructure construction sector improve the energy efficiency of material manufacturing and the service sectors that support construction in China.

Optimal insulation thicknesses according to different indicators for Germany

York Ostermeyer, An De Schryver, Holger Wallbaum

ETH, Switzerland

Studies on the life cycle of buildings show that energy consumption during the use phase of the builidng (running energy consumption) is in most cases the dominating source of their overall impact from air emissions. Insulation is used to reduce the running energy consumption by reducing heath transmission losses. However, producing insulation also results in environmental impacts. Several studies have been conducted on assessing the most cost effective insulation thickness, considering the balance between the buying & installation costs and the lower energy costs during the use of the building. However, there is a strong need in assessing the optimal insulation thickness taking an environmental point of view.

In this study, (i) the optimal insulation thickness for residential buildings is calculated by taking an environmental point of view, and (ii) this environmental optimal insulation thickness is compared with the cost effective one. The environmental impacts during insulation production and environmental gains during the use phase of the house are taken into account using country specific conditions, such as heating and cooling degree days, and region specific energy mixes used by the buildings. Several environmental impact indicators are used, such as CO2-equivalents for climate change, SO2-equivalents for acidification and a single weighted damage score using ReCiPe2008. The results of the study indicate that the optimal insulation thickness depends on the country and chosen indicator. For example, the cost effective insulation thickness is often lower compared to the optimal insulation thickness using climate change as environmental indicator. This is due to the labor intensive installation costs which are not considered when taking an environmental point of view. Finally, recommendations are given on how to derive the optimal insulation thickness considering both environmental and cost effective indicators.

CLEAR – An LCA model for construction

Allan Griffin, Iain Millar, Nick Avery, Nick Coleman, Peter Hodgson

Tata Steel Europe, United Kingdom

The Government's drive in the United Kingdom for zero carbon buildings by 2019 has meant there is a growing need in the construction sector to understand the environmental impacts of a buildings full life cycle, especially with regards to carbon footprint and the impact of the materials contained in them.

Tata Steel Research and Development have developed a comprehensive, fully transparent, cradle-to-grave Life Cycle Assessment model which allows any building made out of any material to be assessed. The model ‘Construction Life-Cycle Environmental Assessment Resource’ (CLEAR) allows the user to define key parameters in terms of building materials, lifetime, maintenance requirements and end-of-life scenarios and calculate the associated environmental impacts. It has also been subject to full critical review as required by the ISO14040 standard.

CLEAR has been used to support customers’ understanding of design options with respect to assessing how the selection of different materials can affect the life cycle impacts. The use of CLEAR has also enabled Tata Steel Europe to contribute to and to provide robust responses to external studies as well as assessing hotspots and the potential for improvement with alternative building solutions.

CLEAR has been used to generate embodied carbon figures for a £1million consortium project looking at 5 major building types with the aim to understand the implications for steel construction from the UK Government's move towards 'zero carbon' buildings. The results from this study have been used to inform guidance issued to the construction industry on how to achieve the zero carbon building target. The development of CLEAR has provided an opportunity to understand and promote the role of steel in low carbon construction.

Going forward CLEAR will be further developed to allow non LCA experts within Tata Steel Europe to utilise the model through a simplified front end when dealing with customers.

Recycled concrete: Environmentally beneficial over virgin concrete?

Arthur Braunschweig1, Susanne Kytzia2, Stefan Bischof3

1E2 Management Consulting, Switzerland; 2Hochschule Rapperswil, Switzerland; 3Holcim, Switzerland

Concrete often makes up for the the major part of a building, based on mass. Swiss environmental construction standards therefore started to ask for the use of recycled concrete, as this reduces gravel use (and the landscape impact) and is said to reduce other enironmental impacts, too.

But is this environmentally useful in an overall ecobalance? In a series of LCA studies for materials and construction projects, the advantages and disadvantages of using recycled or virgin gravel were found.

Interestingly, both energy- and emission-wise, the studies found little differences for virgin or recycled construction concretes . However, lean (poor) concrete with recycled content proved environmentally beneficial. At the same time, construction waste will increasingly be an available resource. The results of the study therefore allow for sound policies on gravel and concrete. The presentation on this study (published in January 2011) will describe the situation in Switzerland and the study's scope and results, and it will allow for discussion on possible conclusions for other markets.

Measuring environmental sustainability: The use of LCA based building performance indicators

Anna Braune1, Bastian Wittstock2

1PE INTERNATIONAL, Germany; 2Fraunhofer Institut for Building Physics, Germany

Today’s common praxis of architects and engineers to create sustainable buildings is often dominated by optimizing and focusing on single aspects such as energy efficiency, water efficiency or “grey energy”. Even today, in the age of information, tradition, conviction or experiences are very often more important in decision-making processes of planners of sustainable buildings than scientifically-based and quantified results of assessments.

In 2009, the European DGNB System for sustainability assessment of buildings was introduced to this group of decision makers. It contains a new way of quantifying a building’s environmental performance: Benchmarks for total building LCA results, using building performance indicators. The starting point of setting the benchmarks used and introducing the quantification method was based on data received from a defined quantity of building LCA results. The successful introduction of this methodology represents a unique way of life cycle management in practice and can serve as an example for other sectors and applications others than the building sector: During the short time-span since its introduction more than 150 buildings already went through the certification process, containing total building LCA calculation.

But how will the benchmarks and the performance indicators be developed in future? Several methods are possible; each standing for different aspired development pathways. In this presentation the use of LCA based building performance indicators is outlined and benchmark development methods discussed.

Comparison of LCA calculation methods in building certification systems

Alexander Passer, Helmuth Kreiner, Peter Maydl

Graz University of Technology, Austria

The political discussion about societal and environmental problems increasingly focuses on the overall concept of sustainable development. The construction sector plays a key role regarding energy and resource consumption as well as solid waste accumulation.

In the past few years a various number of building certification systems like LEED, BREEAM, HQE, DGNB, ÖGNI and TQB were placed on the market to promote green and sustainable buildings. Recently an increasing demand for such labels has been noticeable. In these building certification schemes aspects of sustainability (economic, social and environmental as well as functional and technical) are considered very differently - especially regarding the assessment of the environmental performance. Since 2004 CEN/TC 350 has been working on a set of standards to harmonize the methodology for the sustainability assessment of buildings using a life cycle approach. According to prEN15978 the assessment of the environmental performance of buildings is based on Life Cycle Assessments (LCA) expressed through quantitative assessment categories.

The aim of this paper is to stress the priorities of an assessment of the environmental performance of buildings with the use of the LCA methodology and to compare calculation methods in different building certification systems where a comprehensive analysis was carried out.

The Major result, which will be presented in detail, is a comparison between “simplified” and “complete” LCA to quantify the environmental performance of buildings.

The validation of the assessment methods for the environmental performance shows that the majority are not in line with the upcoming European framework at present. In contrast the assessment methodology used by DGNB/ÖGNI coincides with it. Several criteria are of high complexity, while the accuracy of the results is not satisfying compared to the workload for their assessment.

The minimization of the energy demand requires turning more attention to the environmental performance of the building products used. Otherwise environmental impacts could shift to life cycle stages, which are not addressed in present assessment methods.