Comparative life cycle assessment of conventional and Green Seal-compliant industrial and institutional cleaning products

Purpose  

The goal of this study was to use life cycle assessment (LCA) methodology to assess the environmental impacts of industrial and institutional cleaning products that are compliant with the Green Seal Standard for Cleaning Products for Industrial and Institutional Use, GS-37, and conventional products (non-GS-37-compliant) products.     

Using life cycle thinking to analyze environmental labeling: the case of appearance wood products

Purpose

Growing public concern about the current state of our planet led to the creation of numerous regulations, standards, and certifications for the protection of humans and the environment. Ecolabels were defined for products such as cleaning products, paints, and many others. Wood building products are no exception. The objective of this study is to analyze the existing ecolabelling programs for appearance wood products in nonresidential applications and to evaluate them relatively to their effective role in environment protection or reduction of environment footprint.

Methods

The research was conducted on the most common International Organization for Standardization (ISO) type I ecolabels in North America, the European Union, and Japan. Certification schemes applicable to appearance wood products for nonresidential applications were considered. In a life cycle assessment perspective, certification criteria were compared regarding their ability to consider and integrate environment impacts.

Results and discussion

A wide range of ecolabels can apply to appearance wood products, from indoor air quality to wood from sustainable forest management. Moreover, it has been found that among all certification schemes studied, those integrating the whole life cycle were the most relevant.

Conclusions

The remaining limitation of ISO type I ecolabels is the lack of environmental information enabling the differentiation between products bearing the same ecolabel. This can be overcome by ISO type III environmental product declarations. Thus, allowing a better understanding of the implications related with the use of wood products compared to other materials in the nonresidential building sector.     

Impact of lifetime on US residential building LCA results

Purpose  

Many life cycle assessment (LCA) studies do not adequately address the actual lifetime of buildings and building products, but rather assume a typical value. The goal of this study was to determine the impact of lifetime on residential building LCA results. Including accurate lifetime data into LCA allows a better understanding of a product’s environmental impact that would ultimately enhance the accuracy of LCA results.     

Comparative life cycle assessment and life cycle costing of lodging in the Himalaya

Purpose

The main aim of the study is to assess the environmental and economic impacts of the lodging sector located in the Himalayan region of Nepal, from a life cycle perspective. The assessment should support decision making in technology and material selection for minimal environmental and economic burden in future construction projects.

Methods

The study consists of the life cycle assessment and life cycle costing of lodging in three building types: traditional, semi-modern and modern. The life cycle stages under analysis include raw material acquisition, manufacturing, construction, use, maintenance and material replacement. The study includes a sensitivity analysis focusing on the lifespan of buildings, occupancy rate and discount and inflation rates. The functional unit was formulated as the ‘Lodging of one additional guest per night’, and the time horizon is 50 years of building lifespan. Both primary and secondary data were used in the life cycle inventory.

Results and discussion

The modern building has the highest global warming potential (kg CO_2-eq) as well as higher costs over 50 years of building lifespan. The results show that the use stage is responsible for the largest share of environmental impacts and costs, which are related to energy use for different household activities. The use of commercial materials in the modern building, which have to be transported mostly from the capital in the buildings, makes the higher GWP in the construction and replacement stages. Furthermore, a breakdown of the building components shows that the roof and wall of the building are the largest contributors to the production-related environmental impact.

Conclusions

The findings suggest that the main improvement opportunities in the lodging sector lie in the reduction of impacts on the use stage and in the choice of materials for wall and roof.

     

Inadequate documentation in published life cycle energy reports on buildings

Purpose  

Over the past two decades, energy efficiency of building operation has increased significantly. As a result, the percentage of building life cycle energy attributed to embodied energy has also risen. This percentage, as measured in recent LCA studies, ranges between 2% and 51% and is influenced by the different climatic, infrastructure, and building characteristics that comprise the input data for these studies. Comparing the results of these studies is helpful in understanding how different combinations of these characteristics influence the relative proportions of embodied and operational energy. However, results are also influenced by the subjectivity inherent in each LCA study. Thus, meaningful comparison of results requires documentation of study methodologies, as outlined in ISO 14041.     

Service life of the dwelling stock in Spain

Purpose

Service life of buildings is an essential parameter to evaluate its operational impact in life cycle assessment (LCA). Although most studies assume building service life about 75 to 100 years since no reliable data are available, its accurate quantification is still an unresolved work. To avoid wrong generalizations, the determination of the service life of buildings according to the characteristics of every region is required.

Methods

Life table, a methodology traditionally used in demographic studies, has been used in this paper to estimate the service life of buildings. This methodology has been applied to the dwelling stock of Spain for each of its 19 regions. Data acquisition and sources have been pointed out. The building obsolescence has been considered in the moment that they are in a ruinous state.

Results and discussion

Life table of buildings showed that the average service life of a residential building constructed in 2001 in Spain was expected to be 80 years. Significant different results of service life among regions were found, from 54 years for a building in Ceuta to 95 years in La Rioja. It also showed that 50 % of total Spanish dwellings are younger than 30 years, and they are expected to reach the ruinous state in 2063 to 2081.

Conclusions

Life table applied to buildings allows determining their service life. Its quantification is based on the buildings census, given by official institutions. Building census has to consider the year of construction and the state of conservation of the building to be applied in buildings' life table. Building service life can be used in LCA, renovation and deconstruction of the building stock, and future construction and demolition debris management.     

Achieving consistency in life cycle assessment practice within the European construction sector: the role of the EeBGuide InfoHub

Purpose

The objective of the paper is to discuss the role of a new guidance document for life cycle assessment (LCA) in the construction sector available as an online InfoHub.

Methods

This InfoHub derives from the EeBGuide European project that aimed at developing a guidance document for energy-efficient building LCA studies. The InfoHub is built on reference documents such as the ISO 14040-44 standards, the EN 15804 and EN 15978 standards as well as the ILCD Handbook. The guidance document was filled with expertise and knowledge of several experts. The focus was put on providing scientifically sound, yet practical guidance.

Results

The EeBGuide InfoHub is an online guidance document, setting rules for conducting LCA studies and giving instructions on how to do this. The document has a section on buildings—new and existing—and a section on construction products. It is structured according to the life cycle stages of the European standards EN 15804 and EN 15978, covering all aspects of LCA studies by applying provisions from these standards and the ILCD handbook, wherever applicable. The guidance is presented for different scopes of studies by means of three study types. For the same system boundaries, default values are proposed in early or quick assessment (screening and simplified LCA) while detailed calculation rules correspond to a complete LCA. Such approach is intended to better match the user needs in the building sector.

Conclusions and recommendations

This paper can be viewed as a contribution to the ongoing efforts to improve the consistency and harmonisation in LCA studies for building products and buildings. Further contributions are now needed to improve building LCA guidance and to strengthen links between research, standardisation and implementation of LCA in the construction practice.     

Application of life cycle assessment in the mining industry

Background, aim, and scope  

In spite of the increasing application of life cycle assessment (LCA) for engineering evaluation of systems and products, the application of LCA in the mining industry is limited. For example, a search in the Engineering Compendex database using the keywords “life cycle assessment” results in 2,257 results, but only 19 are related to the mining industry. Also, mining companies are increasingly adopting ISO 14001 certified environmental management systems (EMSs). A key requirement of ISO certified EMSs is continual improvement, which can be better managed with life cycle thinking. This paper presents a review of the current application of LCA in the mining industry. It discusses the current application, the issues, and challenges and makes relevant recommendations for new research to improve the current situation.     

The guidelines for social life cycle assessment of products: just in time!

Purpose  

Authors of different sustainability journals, including authors of articles in past issues of the International Journal of Life Cycle Assessment have acknowledged the rising interest and the pressing need for a social and socio-economic life cycle assessment methodology and identified challenges in its development and implementation. Social life cycle assessment (LCA) allows identification of key issues, assessing, and telling the story of social conditions in the production, use, and disposal of products. In this article, the United Nations Environment Programme/The Society of Environmental Toxicology and Chemistry Guidelines for Social Life Cycle Assessment of Products will be presented.     

The influence of durability and recycling on life cycle impacts of window frame assemblies

Purpose

A set of comparative life cycle assessment case studies were undertaken to explore key issues relating to the environmental impacts of building materials. The case studies explore modeling practice for long-life components by investigating (1) recycled content and end-of-life recycling scenarios and (2) service life and maintenance scenarios. The study uses a window unit frames as the object of comparison, allowing for exploration of multiple materials and assembly techniques.

Methods

Four window frame types were compared: aluminum, wood, aluminum-clad wood, and unplasticized PVC (PVCu). These used existing product life cycle inventory data which included primary frame material, coatings, weather stripping sealants, but not glazing. The functional unit was a window frame required to produce 1 m² of visible glazing, with similar thermal performance over a building lifespan of 80 years. The frames were compared using both the end-of-life and recycled content methods for end-of-life scenarios. The models were also tested using custom-use scenarios.

Results and discussion

Well-maintained aluminum window frames proved to be the least impactful option across all categories, in large part due to the credits delivered from recycling and expectations of long-life. Wood window frames had the least variability associated with maintenance and durability. The global warming potential (GWP) of a moderately maintained aluminum assembly was found to be 68 % less than PVCu and 50 % less than aluminum-clad wood. Using a long-life scenario, wood windows were found to have a 7 % lower GWP than the long-life scenario for aluminum-clad woods. Moderately and well-maintained aluminum windows require less energy to be produced and maintained over their lifetime than any of the wood scenarios. Expectations of service life proved to be the most important factor in considering environmental impact of frame materials.

Conclusions

The research shows significant gaps in available data—such as average realized life expectancies of common building components—while further underscoring that recycling rates are a driving factor in the environmental impact of aluminum building products. A modeling shift from the recycled content method to the end-of-life recycling method should promote goals of material recovery over pursuit of material with high recycled content. Hybrid methods, such as the use of Module D, may bridge the divide between these two approaches by providing due credit for use of recycled material, while supporting a design for recycling ethos. Further research is needed on how design and construction decisions affect collection and recovery rates in practice.

     

A method for improving Centre for Environmental Studies (CML) characterisation factors for metal (eco)toxicity — the case of zinc gutters and downpipes

Background, aim and scope  

The environmental impact of building products made from heavy metals has been a topic of discussion for some years. This was fuelled by results of life cycle assessments (LCAs), where the emission of heavy metals strongly effected the results. An issue was that the characterisation factors of the Centre for Environmental Studies (CML) 2000 life cycle impact assessment (LCIA) methodology put too much emphasis on the impact of metal emissions. We adjusted Zn characterisation factors according to the most recent insights in the ecotoxicity of zinc and applied them in an LCA using zinc gutters and downpipes as an example.     

Geometric service life modelling and discounting,a practical method for parametrised life cycle assessment

Purpose

To evaluate the long-term advantage of reusing building elements, including reduced material consumption and waste production, life cycle assessments are purposeful. To translate these assessments in relevant design advices, it is necessary to model accurately the service life of the considered elements and acknowledge the related uncertainties. Practical methods to do this are nevertheless lacking. In reaction, this paper proposes a new assessment method: geometric service life modelling and discounting.

Methods

The developed method is extensively parametric. Its formulas express an element’s service life in terms of a limited number of variables. This facilitates the evaluation of large series of elements as well as the automation of uncertainty analyses. Further, the method tackles different modelling complexities such as the interaction between replacements and refurbishments. Taking into account these complexities aligns the assessments with realistic service lives. For the presentation of the developed method, a focus on life cycle costing is chosen.

Results and discussion

In this paper, the outcomes of the newly developed method are compared to those of an existing calculation method and benchmarked with the manual modelling and assessment of 390 simplified building elements. This comparison is based on three indicators characterising the methods’ accuracy: the number of interventions, their individual impact and their resulting net present value. For each indicator, geometric discounting led to a considerable increase of accuracy compared to the existing method.

Conclusions

From this comparison, it is concluded that geometric service life modelling and discounting offers not only a well-defined procedure for parametrised life cycle assessment studies, this method is also more accurate than the existing one. Moreover, the uncertainty analyses it facilitates illustrate how detailed assessment outcomes and relevant design advices about the effectiveness of element reuse can be obtained. Nevertheless, further research about the method’s practical implementation is required.

     

Framework for integrating animal welfare into life cycle sustainability assessment

Purpose

This study seeks to provide a framework for integrating animal welfare as a fourth pillar into a life cycle sustainability assessment and presents three alternative animal welfare indicators.

Methods

Animal welfare is assessed during farm life and during slaughter. The indicators differ in how they value premature death. All three consider (1) the life quality of an animal such as space allowance, (2) the slaughter age either as life duration or life fraction, and (3) the number of animals affected for providing a product unit, e.g. 1 Mcal. One of the indicators additionally takes into account a moral value denoting their intelligence and self-awareness. The framework allows for comparisons across studies and products and for applications at large spatial scales. To illustrate the framework, eight products were analysed and compared: beef, pork, poultry, milk, eggs, salmon, shrimps, and, as a novel protein source, insects.

Results and discussion

Insects are granted to live longer fractions of their normal life spans, and their life quality is less compromised due to a lower assumed sentience. Still, they perform worst according to all three indicators, as their small body sizes only yield low product quantities. Therefore, we discourage from eating insects. In contrast, milk is the product that reduces animal welfare the least according to two of the three indicators and it performs relatively better than other animal products in most categories. The difference in animal welfare is mostly larger for different animal products than for different production systems of the same product. This implies that, besides less consumption of animal-based products, a shift to other animal products can significantly improve animal welfare.

Conclusions

While the animal welfare assessment is simplified, it allows for a direct integration into life cycle sustainability assessment. There is a trade-off between applicability and indicator complexity, but even a simple estimate of animal welfare is much better than ignoring the issue, as is the common practice in life cycle sustainability assessments. Future research should be directed towards elaborating the life quality criterion and extending the product coverage.

     

Whole life considerations in it procurement

Goal, Scope and Background  

Waste associated with the manufacture, use, and disposal of electronic products, or e-waste, is a growing threat to the environment. IT procurement professionals can have a positive affect against that threat through careful consideration of the environmental awareness of their vendors.     

Comparative life cycle assessment of rapeseed oil and palm oil

Background, aim and scope  

The environmental effect of globalisation has been debated intensively in the last decades. Only few well-documented analyses of global versus local product alternatives exist, whilst recommendations on buying local are vast. At the same time, the European Environmental Agency’s Third Assessment concludes that the resource use within the EU is stabilising at the expense of increased resource use for import of products to the EU. Taking its point of departure in vegetable oils, this article compares rapeseed oil and palm oil as a local and a global alternative for meeting the increasing demand for these products in the EU. By using detailed life cycle assessment (LCA), this study compares the environmental impacts and identifies alternative ways of producing rapeseed oil and palm oil to the EU market in order to reduce environmental impacts.     

Generic quality of life assessment in dementia patients: a prospective cohort study

Background  

Quality of life (QoL) is increasingly used to characterize the impact of disease and the efficacy of interventions.     

Social life cycle assessment for material selection: a case study of building materials

Purpose

Sustainability of a material-based product mainly depends on the materials used for the product itself or during its lifetime. A material selection decision should not only capture the functional performance required but should also consider the economical, social, and environmental impacts originated during the product life cycle. There is a need to assess social impacts of materials along the full life cycle, not only to be able to address the “social dimension” in sustainable material selection but also for potentially improving the circumstances of affected stakeholders. This paper presents the method and a case study of social life cycle assessment (S-LCA) specialized for comparative studies. Although the authors’ focus is on material selection, the proposed methodology can be used for comparative assessment of products in general.

Methods

The method is based on UNEP/SETAC “guidelines for social life-cycle assessment of products” and includes four main phases: goal and scope definition, life cycle inventory analysis, life cycle impact assessment, and life cycle interpretation. However, some special features are presented to adjust the framework for materials comparison purpose. In life cycle inventory analysis phase, a hot spot assessment is carried out using material flow analysis and stakeholder and experts’ interviews. Based on the results of that, a pairwise comparison method is proposed for life cycle impact assessment applying analytic hierarchy process. A case study was conducted to perform a comparative assessment of the social and socio-economic impacts in life cycle of concrete and steel as building materials in Iran. For hot spot analysis, generic and national level data were gathered, and for impact assessment phase, site-specific data were used.

Result and discussion

The unique feature of the proposed method compared with other works in S-LCA is its specialty to materials and products comparison. This leads to some differences in methodological issues of S-LCA that are explained in the paper in detail. The case study results assert that “steel/iron” in the north of Iran generally has the better social performance than “concrete/cement.” However, steel is associated with many negative social effects in some subcategories, e.g., freedom of association, fair salary, and occupational health in extraction phase. Against, social profile of concrete and cement industry is damaged mainly due to the negative impact of cement production on safe and healthy living condition. The case study presented in this article shows that the evaluation of social impacts is possible, even if the assessment is always affected by subjective value systems.

Conclusions

Application of the UNEP/SETAC guidelines in comparative studies can be encouraged based on the results of this paper. It enables a hotspot assessment of the social and socio-economic impacts in life cycle of alternative materials. This research showed that the development of a specialized S-LCA approach for materials and products comparison is well underway although many challenges still persist. Particularly characterization method in life cycle impact assessment phase is challenging. The findings of this case study pointed out that social impacts are primarily connected to the conduct of companies and less with processes and materials in general. These findings confirm the results of Dreyer et al. (Int J Life Cycle Assess 11(2):88–97, 2006). The proposed approach aims not only to identify the best socially sustainable alternative but also to reveal product/process improvement potentials to facilitate companies to act socially compatible. It will be interesting to apply the UNEP/SETAC approach of S-LCA to other materials and products; materials with a more complex life cycle will be a special challenge. As with any new method, getting experience on data collection and evaluation, building a data base, integrating the method in software tools, and finding ways for effective communication of results are important steps until integrating S-LCA in routine decision support.     

Environmental performance of social housing in emerging economies: life cycle assessment of conventional and alternative construction methods in the Philippines

Purpose

The environmental impact of the social building stock is relevant, particularly in emerging economies. Life cycle thinking is not yet established, however. Locally available, alternative building concepts could potentially reduce the environmental impact of the construction segment. This paper examines the environmental performance of “as-built” low-cost housing for an example of the Philippines, and the potential to reduce its environmental impact through use of three alternative building technologies: cement–bamboo frames, soil–cement blocks, and coconut board-based housing.

Methods

Life cycle assessment models are implemented and evaluated with software SimaPro, using the single-impact indicators global warming potential (GWP) and cumulative energy demand (CED) and the multi-impact indicator Impact2002+. According to EN 15978, the life cycle phase product and construction process (A), use stage (B), end-of-life (C) and supplementary information beyond the building life cycle (D) have been assessed. Theoretically calculated inflows from standard construction procedures used in phase A have been verified with 3 years of empirical data from implemented construction projects. For phases B, C and D, attention was given to service life, use-phase, allocation of waste products, biogenic carbon and land-use assumptions. Scenarios reflect the actual situation in the emerging economy. Processes, such as heat recovery from thermal utilization, which are not existing nor near to implementation, were excluded.

Results and discussion

For an assessment of the phases A–B–C–D with GWP, a 35% reduction of environmental impact for soil–cement blocks, 74% for cement–bamboo frame, and 83% for coconut board-based houses is obtained relative to a concrete reference house. In absolute terms, this relates to a reduction of 4.4, 9.3, and 10.3 t CO₂ equivalents over a service life of 25 years. CED showed higher impacts for the biogenic construction methods coconut board and cement–bamboo frames of +8.0 and +4.7%, while the soil–cement technology was evaluated ?7.1% compared to GWP. Sixteen of 17 midpoint categories of Impact2002+ confirmed an overall reduction potential of the alternative building methods, with the midpoint category land occupation being the exception rating the conventional practice over the alternatives.

Conclusions

It is concluded that the alternative construction technologies have substantial potential to reduce the environmental burden caused by the social housing sector. The service life of the alternative technologies plays a vital role for it. LCA for emerging economies needs to incorporate realistic scenarios applicable at their current state or belonging to the most probable alternatives to ensure valuable results. Recommendations for further research are provided.

     

Consequential life cycle assessment: a review

Purpose  

Over the past two decades, consequential life cycle assessment (CLCA) has emerged as a modeling approach for capturing environmental impacts of product systems beyond physical relationships accounted for in attributional LCA (ALCA). Put simply, CLCA represents the convergence of LCA and economic modeling approaches.     

Dynamic life cycle assessment: framework and application to an institutional building

Purpose

This paper uses a dynamic life cycle assessment (DLCA) approach and illustrates the potential importance of the method using a simplified case study of an institutional building. Previous life cycle assessment (LCA) studies have consistently found that energy consumption in the use phase of a building is dominant in most environmental impact categories. Due to the long life span of buildings and potential for changes in usage patterns over time, a shift toward DLCA has been suggested.

Methods

We define DLCA as an approach to LCA which explicitly incorporates dynamic process modeling in the context of temporal and spatial variations in the surrounding industrial and environmental systems. A simplified mathematical model is used to incorporate dynamic information from the case study building, temporally explicit sources of life cycle inventory data and temporally explicit life cycle impact assessment characterization factors, where available. The DLCA model was evaluated for the historical and projected future environmental impacts of an existing institutional building, with additional scenario development for sensitivity and uncertainty analysis of future impacts.

Results and discussion

Results showed that overall life cycle impacts varied greatly in some categories when compared to static LCA results, generated from the temporal perspective of either the building's initial construction or its recent renovation. From the initial construction perspective, impacts in categories related to criteria air pollutants were reduced by more than 50 % when compared to a static LCA, even though nonrenewable energy use increased by 15 %. Pollution controls were a major reason for these reductions. In the future scenario analysis, the baseline DLCA scenario showed a decrease in all impact categories compared with the static LCA. The outer bounds of the sensitivity analysis varied from slightly higher to strongly lower than the static results, indicating the general robustness of the decline across the scenarios.

Conclusions

These findings support the use of dynamic modeling in life cycle assessment to increase the relevance of results. In some cases, decision making related to building design and operations may be affected by considering the interaction of temporally explicit information in multiple steps of the LCA. The DLCA results suggest that in some cases, changes during a building's lifetime can influence the LCA results to a greater degree than the material and construction phases. Adapting LCA to a more dynamic approach may increase the usefulness of the method in assessing the performance of buildings and other complex systems in the built environment.