Holger Wallbaum

Impact of sustainable office buildings on occupant's comfort and productivity

Purpose – The purpose of this paper is to research the impact of sustainable office buildings on occupants comfort and self‐assessed performance and work engagement.Design/methodology/approach – The research consists in an empirical study of 18 office buildings and is based on survey data from almost 1,500 employees.Findings – The study shows that the building itself has a clear impact on the comfort level of the building user. Also, the positive impact of certain features, such as operable windows and the absence of air conditioning, can be clearly identified. While productivity is not directly correlated to comfort levels, work engagement is. Generally, the analysis shows that specific building aspects seem to have an influence on user comfort and with that, also an impact on productivity; however, this impact appears to be limited.Originality/value – This is a very important insight since this shows the connection between employee and company and thus demonstrates that a high user comfort can reduce t...

Multidimensional Pareto optimization as an approach for site-specific building refurbishment solutions applicable for life cycle sustainability assessment

PurposeThis paper addresses the application and potential of LCSA in the built environment with a focus on refurbishments of residential buildings. It specifically addresses the phenomenon of interchange of building technologies efficiencies under different life time assessments from economy, ecology and social fields. An approach of optimization rather than hard target numbers is proposed as win–win–win situations are unlikely.MethodsA multidimensional Pareto optimization methodology, using LCC, LCA combined with first stages of a social assessment in a feasibility study but potentially later full SLCA, is proposed, which site-specifically visualizes the interchange between different options in building design or modification, and evaluates optimal overall concepts. LCA and LCC are used to analyze a case study from an EU project named BEEM-UP in which solutions for large-scale uptake of refurbishment strategies are developed. Social frame conditions are taken into account by identifying the driving technologies and feeding the consequences of their implementation for the residents into the tenant involvement part of the project.Results and discussionThe calculations prove that the general assumptions leading to the methodology hold true at least for this case study. A clear Pareto-optimal curve is visible when assessing LCC and LCA. The example buildings results show certain systems to be dominating clusters on the figures while others clearly can be identified as not relevant. Several of the driving technologies however fail to be applicable because of social frame conditions, e.g., clear requests by the tenants. Based on the conclusions, the potential for including SLCA as a third dimension in the methodology and possible visualization options are discussed.ConclusionsThe development in the field of social indicators in the building sector has to be strengthened in order to come up with a holistic picture and respectively with appropriate responses to current challenges. While some solutions identified in the LCC/LCA assessment also have good social characteristics, several others have not and solutions identified as lacking might have social advantages that are currently left out of consideration The upcoming Standards EN 15643-5 and ISO 15686-x are a promising step in this direction as is the work to create a conceptual framework for impact assessment within SLCA by the scientific community.

Prioritizing Sustainability Criteria in Urban Planning Processes: Methodology Application

Since the beginning of the sustainability debate approximately 20 years ago, all parties involved in the urban planning process have been expected to devise sustainable solutions to meet the challenges of the 21st century. Potential to include sustainability criteria is present in the strategic planning stage and during the initial studies of a project. However, instruments available at these early stages are rare and show numerous weaknesses. The present study intends to close this gap by developing an instrument for the prioritization of sustainability criteria in urban planning processes. It is based on the Sustainable Building Tool 07 (SBTool 07), a comprehensive and well-established tool for the assessment of sustainability of construction projects, key issues pertaining to the initial planning stages are identified via a materiality matrix—a method established for corporate sustainability reporting. The resulting method has been tested in a competition in the Icelandic city of Reykjavik. Results include a materiality matrix on stakeholder priorities and the relevance of criteria to sustainability across the life cycle as well as a core set of 19 criteria to be addressed in Reykjavik.

Environmental Impact of Buildings—What Matters?

The goal of this study was to identify drivers of environmental impact and quantify their influence on the environmental performance of wooden and massive residential and office buildings. We performed a life cycle assessment and used thermal simulation to quantify operational energy demand and to account for differences in thermal inertia of building mass. Twenty-eight input parameters, affecting operation, design, material, and exogenic building properties were sampled in a Monte Carlo analysis. To determine sensitivity, we calculated the correlation between each parameter and the resulting life cycle inventory and impact assessment scores. Parameters affecting operational energy demand and energy conversion are the most influential for the buildings total environmental performance. For climate change, electricity mix, ventilation rate, heating system, and construction material rank the highest. Thermal inertia results in an average 2-6% difference in heat demand. Nonrenewable cumulative energy demand of wooden buildings is 18% lower, compared to a massive variant. Total cumulative energy demand is comparable. The median climate change impact is 25% lower, including end-of-life material credits and 22% lower, when credits are excluded. The findings are valid for small offices and residential buildings in Switzerland and regions with similar building culture, construction material production, and climate.

Environmental product declarations entering the building sector: critical reflections based on 5 to 10 years experience in different European countries

PurposeGrowing awareness of the environmental performance of construction products and buildings brings about the need for a suitable method to assess their environmental performance. Life cycle assessment (LCA) has become a widely recognised and accepted method to assess the burdens and impacts throughout the life cycle. This LCA-based information may be in the form of environmental product declarations (EPD) or product environmental footprints (PEF), based on reliable and verifiable information. All of these use LCA to quantify and report several environmental impact categories and may also provide additional information. To better understand on the one hand existing EPD programmes (EN 15804) for each country and on the other the recent developments in terms of EU reference document (e.g. PEF), the authors decided to write this review paper based on the outcomes of the EPD workshop that was held prior to SB13 Graz conference.MethodsThis paper presents the state of the art in LCA and an overview of the EPD programmes in five European countries (Austria, Belgium, France, Germany, Switzerland) based on the workshop in the first part and a comprehensive description and comparison of the PEF method and EN 15804 in the second part. In the last part, a general conclusion will wrap up the findings and results will provide a further outlook on future activities.Results and discussionThe high number of EPD programmes underlines the fact that there is obviously a demand for assessments of the environmental performance of construction materials. In the comparison between and experiences of the different countries, it can be seen that more similarities than differences exist. A comparison between PEF and EPD shows differences, e.g. LCIA impact categories and recycling methodology.ConclusionsIndependent of raising awareness of the construction material environmental performance, the existence of so many environmental claims calls for clarification and harmonisation. Additionally, construction materials being assessed in the voluntary approaches have to follow the harmonised approach following the principles of the European Construction Products Regulation (regulated) not to foster barriers of trade. The authors therefore highly appreciate the most recent activities of the sustainability of construction works (CEN/TC 350 committee http://portailgroupe.afnor.fr/public_espacenormalisation/CENTC350/index.html) currently working on these issues at the EU level. Finally, the LCA community is further encouraged to increase the background life cycle inventory data and life cycle inventory modelling as well as the meaningfulness of certain environmental impact categories, such as toxicity, land use, biodiversity and resource usage.

Rental price and sustainability ratings: which sustainability criteria are really paying back?

Given the centrality of the price mechanism to resource allocation in market economies, the effect of sustainable construction on real estate prices has become an increasingly important empirical issue for market participants and policy makers in the real estate sector. Drawing upon a sample of approximately 2500 residential building units in Switzerland, this study assesses the effects of buildings’ sustainability on their rental prices. In contrast to the vast majority of previous studies that have focused on the price effects of eco-labels, this study investigates the effects of individual sustainability attributes. Overall, we find a positive relationship between the environmental performance of residential buildings and their rental levels. Sustainable building characteristics, especially those which enhance the water efficiency, the health and comfort level and the building’s safety and security, have significant positive price effects. It is argued that the unexpected negative relationship between energy performance and rental prices is attributed to the bundling of energy costs and rents in Swiss lease structures.

Life Cycle Assessment of Representative Swiss Road Pavements for National Roads with an Accompanying Life Cycle Cost Analysis

The subject of this paper is an environmental life cycle assessment (LCA) and life cycle cost analysis (LCCA) of processes needed to construct and maintain representative Swiss asphalt, concrete, and composite pavements (including subbase layers) applicable for the Swiss national road network over a period of 75 years. The environmental indicators analyzed are the global warming potential indicator, the nonrenewable cumulative energy demand, and the Swiss ecological scarcity indicator. Processes of the use phase of the road (fuel consumption, noise, etc.) have been evaluated qualitatively based on intensive research. The study shows that the global warming potential of concrete and asphalt pavements equilibrates over the analysis period and that concrete pavements compared to asphalt and composite pavements offer advantages in regards to the nonrenewable cumulative energy demand, the ecological scarcity indicator, and life cycle costs. The qualitative evaluation of the processes of the use phase shows for example the positive qualities of concrete pavements regarding fuel consumption and permanent noise properties.

Life-Cycle Assessment of the Production of Swiss Road Materials

Sustainable development demands contributions across all economic sectors. Thus, the infrastructure field, in this case road infrastructure, also has to contribute its part by generating road materials and road construction with lower environmental impacts. This paper analyzes the environmental potentials hidden in road materials used in Swiss road pavements. For several materials used in road construction, cradle-to-gate life-cycle assessments (LCA) were performed, taking into account all environmental impacts from raw material extraction to the finished product at the production plant. Environmental improvement potentials were analyzed for the production of asphalt mixtures, concrete mixtures, and subbase mixtures, using eight different environmental impact indicators. The results show differences in the environmental impact between best case and current status production setup of up to 54% for asphalt mixtures, 38% for concrete mixtures, and 93% for subbase mixtures.

Environmental analysis of new construction and maintenance processes of road pavements in Switzerland

The subject of this paper is an environmental analysis of processes needed to construct (material production, pavement construction, transport) and maintain (pavement deconstruction, recycling, material production, pavement construction, transport) representative Swiss asphalt, concrete and composite pavements (including subbase layers). The analysed environmental indicators are the IPCC Global Warming Potential indicator, the Ecological Scarcity Indicator and the Non-renewable Cumulative Energy Demand indicator. It is shown that material production processes have the largest impact on the values of the analysed indicators, and that pavement construction and deconstruction processes have a marginal impact on the analysed indicators in comparison to material production, transport and recycling processes. It is also demonstrated that the values of the IPCC Global Warming Potential indicator and the Ecological Scarcity indicator for the processes needed to construct and maintain concrete and composite pavements are higher than those for all processes required to construct and maintain asphalt pavements, due to the greater thickness of concrete and composite pavements. The values of the Non-Renewable Cumulative Energy Demand indicator are higher for processes applied to construct and maintain asphalt pavements than for concrete pavements, due to the use of bitumen within asphalt pavements, which causes a depletion of fossil energy resources.

Constraints to implementation of sustainability indicator systems in five Asian cities

Contemporary studies on sustainability indicator systems (SISs) typically focus on the technical advancement of indicator construction, on qualitative impacts of indicator programmes and on impacts on governance, decision-making and sustainability as a social construct. Yet, their implementation so far has rarely been addressed, even though monitoring and the use of indicator results fall far behind the number of SISs developed. This study aims at the identification of requirements for the development of and constraints to the implementation of SISs in five Asian cities of developing countries. Interviews with local key actors are held, and a qualitative content analysis is carried out. Findings include evidence on the degree of indicator implementation in the case study cities, a hexagonal model for the classification of requirements and constraints, as well as general conclusions for barriers to the use of SISs.