Building Life Cycle Assessment Research Articles

Inventory regionalizing of background data: influence on building life cycle assessment and carbon reduction strategies

Inventory regionalizing of background data: influence on building life cycle assessment and carbon reduction strategies

Comparison of Embodied Carbon Footprint of a Mass Timber Building Structure with a Steel Equivalent

The main purpose of this study is to quantify and compare the embodied carbon (EC) from the materials used or designed to build the Adohi Hall, a residence building located on the University of Arkansas campus in Fayetteville, AR. It has been constructed as a mass timber structure. It is compared to the same building design with a steel frame for this study. Based on the defined goal and scope of the project, all materials used in the building structure are compared for their global warming potential (GWP) impact by applying a life cycle assessment (LCA) using a cradle-to-construction site system boundary. This comparative building LCA comprises the product stage (including raw material extraction, processing, transporting, and manufacturing) plus transportation to the construction site (nodule A1–A4, according to standard EN 15804 definitions). In this study, GWP is primarily assessed with the exclusion of other environmental factors. Tally®, as one of the most popular LCA tools for buildings, is used in this comparative LCA analysis. In this study, the substitution of mass timber for a steel structure with a corrugated steel deck and concrete topping offers a promising opportunity to understand the GWP impact of each structure. Mass timber structures exhibit superior environmental attributes considering the carbon dioxide equivalent (CO2 eq). Emissions per square meter of gross floor area for mass timber stand at 198 kg, in stark contrast to the 243 kg CO2 eq recorded for steel structures. This means the mass timber building achieved a 19% reduction in carbon emissions compared to the functional equivalent steel structure within the building modules A1 to A4 studied. When considering carbon storage, about 2757 tonnes of CO2 eq are stored in the mass timber building, presenting further benefits of carbon emission delays for the life span of the structure. The substitution benefit from this construction case was studied through the displacement factor (DF) quantification following the standard process. A 0.28 DF was obtained when using mass timber over steel in the structure. This study provides insights into making more environmentally efficient decisions in buildings and helps in the move forward to reduce greenhouse gas (GHG) emissions and address GWP mitigation.

Literature Review on The Whole Life Cycle Assessment of Passive Buildings in The Context of Dual Carbon Emissions

With the increasing global demand for sustainable buildings, passive building design has become an area of concern. The design concept of passive buildings is known for its efficient energy use and excellent indoor environmental quality. However, there is a need to delve deeper in order to fully assess the economics and sustainability of passive buildings. The whole life cycle management of passive buildings is a relatively new management concept, and the evaluation research of the whole life cycle of passive buildings under the dual-carbon target is still limited. This paper reviews the evaluation methods and criteria based on the whole life cycle of passive buildings. The literature review includes research conducted over the past two decades and will focus on evaluation indicators for passive buildings. Many reviews present evaluation indicators for low energy design in the full life cycle evaluation of passive buildings and discuss future design directions. This literature review serves as a preliminary step to guide the evaluation criteria of passive buildings in light of China's two-carbon target, which will help to enrich the evaluation indicators of passive buildings and promote the transition to high-quality development of passive buildings.

Visualisation of building life cycle assessment results using 3D business intelligence dashboards

Visualisation of building life cycle assessment results using 3D business intelligence dashboards

On the estimation of interior walls in the district-scale Life Cycle Assessment of buildings

The large-scale Life Cycle Assessment (LCA) of buildings supports decision-making processes in reaching the climate goals of the building sector. Yet, the considerable amount of data required for detailed assessments hinders the method. This is particularly the case for buildings’ interior, which oftentimes surpasses the normative cutoff criteria’s negligibility threshold, and thus has to be considered in building LCA. In light of interior walls’ contribution to buildings’ overall environmental impacts, and a lack of cohesive determination methods thereof, this article proposes a parametric approach to complement an existing district-scale LCA workflow for residential buildings. The approach is applied to an exemplary residential district, using a Latin Hypercube Sampling (LHS) method, to establish a range of interior wall areas and resulting effects on LCA calculations. Thereafter, the outcome is compared with the results of a preexisting approach and validated project data. The novel method is capable of significantly reducing the tool’s overestimation of interior wall areas from 400% to a value between 7% and 53%. However, it is evident that the area estimation in terms of Life Cycle Inventory (LCI) needs to be complemented with a more accurate material setup, which could be differentiated by building archetypes.

Digital twins a digital transformation for management of the construction industry

In recent years technologies have been transforming working relationships in the construction industry. To dynamize the sector, new ways are sought to obtain better control over its lifecycle.  The goals are to achieve cost savings, improvement in the quality of services, greater security and less environmental impact.  Important information, to reach such goals, is generated during the project, the construction, the use/upkeep of assets.  Nevertheless, this information is not used properly, because it requires participative management for the data to be kept updated and available in real time.  A process that allows for this management right from the project-planning phase is Building Information Modeling (BIM).  Its association with cloud-based communication platforms allows users to access all the data in real time.  Allied to the resources of the Internet of Things (IoT), BIM makes it possible to transfer data to specific software that assist this information to remain alive during the whole lifecycle of the construction.  The cloud-based platforms integrated to the BIM and the IoT, make it possible to digitalise and transfer the information related to the construction in real time, to create the Digital Twin (DT).  With this DT all this information can be managed on one only digital platform which permits intelligent constructions and operational excellence in the sector.  In this article, concepts relating to the creation of a DT are analysed by means of the Life Cycle Assessment (LCA) for buildings.  A review of the literature was also carried out on the recent applications of the DT and, especially, in the construction industry.  It became clear in the study that in recent years the DT is gradually being implemented in different sectors.  Most of the research presents a review of the literature followed by small-scale experiments or case studies.  It was found that the concept of DT has attracted the attention of the construction industry, and debate on the theme is developing rapidly in the academic sector, so as to establish the ways of effectively developing it in the construction industry.

SLiCE: An open building data model for scalable high-definition life cycle engineering, dynamic impact assessment, and systematic hotspot analysis

Building construction and operation are responsible for around 40 % of global energy-related greenhouse gas emissions. To identify emissions reduction and removal potentials as well as wider environmental impacts, researchers, policy, and decision makers need comprehensive life cycle sustainability assessment (LCSA) insights on individual buildings and building stocks at large.This article proposes an open building data model for Scalable, high-definition Life Cycle Engineering (SLiCE) as a solution to overcome the limitations identified for existing models. The article departs from conceptualizing the problem within the Space-Time-Indicator Nexus; presents the proposed SLiCE data structure; and showcases practical uses of SLiCE data for dynamic assessment of climate change impact as well as for systematic environmental hotspot analysis.The open SLiCE building data model and SLiCE hotspot analysis tool are henceforth available for implementation within life cycle assessment (LCA) of building and building stocks, enabling comprehensive insights on buildings' environmental impacts across spatiotemporal scales.

Establishment of an Environmental Impact Factor Database for Building Materials to Support Building Life Cycle Assessments in China

The construction industry increasingly poses significant threats on the environment, highlighting the importance of developing life cycle assessments (LCAs). Research on building LCA databases has been carried out in many countries. However, in China, the absence of public data for environmental impact assessments poses significant challenges for building life cycle assessments (LCA). Therefore, this study aims to facilitate the life cycle assessment of buildings in China by comparing and analyzing databases from South Korea and the European Union. The goal is to establish a unit-based environmental impact database for Chinese building materials. Three environmental impact factors of ten major building materials in these three databases were compared and a basis for the inter-application of the databases was established. Based on the combination of the analysis results, the supplementation of the environmental impact factor database of building materials in China was proposed. In addition, a case study using a quantity take-off (QTO) for an actual building in China was performed to review the plan’s applicability.

LCA of net-zero energy residential buildings with different HVAC systems across Canadian climates: A BIM-based fuzzy approach

The urgency of addressing building energy consumption's impact on climate change, particularly from fossil fuels, is of great significance. This study investigates the environmental and economic aspects of different climatic conditions in Canadian regions throughout a building's life cycle. Focusing on HVAC systems, choice between electricity, natural gas and solar sources. Using whole building life cycle assessments and energy simulations, the research examines 36 scenarios, considering three popular HVAC systems with six weather conditions. To reduce uncertainties, the study employs BIM and fuzzy-based methods. The results identified consistent environmental impacts across scenarios, averaging 1.4 tonnes CO2eq/m2 in GHG, 1.74 kg/m2 in PM2.5, and 3.61 kg/m2 in SO2 emissions for a typical net-zero energy building in Canada. Variations primarily result from operational, embodied, and transportation stages, rather than other life cycle stages. Colder climates, like central Canada, exhibit higher energy demands and increased global warming potential. Ground Source Heat Pump (GSHP has lower emissions despite higher upfront costs and is preferred when considering both environmental and economic factors. However, in mild climates like Vancouver, Air Source Heat Pump (ASHP) is optimal. Photovoltaic panels enhance HVAC system feasibility across various options. The study provides insights for building industry stakeholders, including designers, owners, and policymakers.

Global building life cycle assessment: Comparative study of steel and concrete frames across European Union, USA, Canada, and Australia building codes

The construction industry has one of the worst carbon footprints among the major industries and accounts for 39% of the world’s total greenhouse gas emissions. One of the main determinants of the carbon footprint of a building is the type of frame used in its structure. The most commonly used types of structural frames are steel and concrete frames, each having its own advantages and drawbacks. This study estimates and compares the carbon footprint of two buildings designed with a steel frame and a concrete frame, respectively, based on the building structural design codes of the European Union (EC), USA (ACI, AISC), Canada (CSA), and Australia (AS). The primary objective of this study is to conduct a comprehensive comparison of carbon emissions from these buildings. The focus extends beyond operational emissions to include an assessment of embodied emissions using the life cycle assessment (LCA) methodology. This comparison aims to gauge the overall emissions of the buildings and also evaluate the impact of major building codes on their carbon footprint. The results show that among the steel frame structures designed based on different building codes, the one designed according to the codes of the European Union has the highest carbon emission (142 kgCO2-eq/m2 floor area), and the one designed based on the Australian code has the lowest carbon emission (119 kgCO2-eq /m2). Among the concrete frame structures, the one designed based on the Canadian codes had the highest carbon emission (221 kgCO2-eq/m2), but again, the structure designed according to the Australian code had the lowest carbon emission (134 kgCO2-eq /m2). Carbon emission estimations for the operational phase showed that, while Canadian Cities exhibit the highest portion of energy consumption, its utilization of a green electricity grid results in the lowest operational carbon emissions. In contrast, Sydney, despite having the lowest energy consumption, exhibits the highest level of operational carbon emissions due to its reliance on coal for electricity generation. The findings of this study can serve as a valuable benchmark for policymakers in various areas. They can identify the shortcomings and advantages of their region's building codes, paving the way for targeted modifications that contribute to achieving a more sustainable built environment in their respective locales.

Bottom-up LCA building stock model: Tool for future building-management scenarios

Residential buildings have a substantial impact on global environmental impacts. In this paper we present a model that assesses impacts from materials (embodied impacts) as well as from heating (operational impacts) for all residential buildings in Switzerland. Our model builds on an existing high-resolution spatio-temporal building stock model, which estimates the space heating demand of buildings, based on building property and site data. In this work we additionally include the impacts of materials extraction, production, transportation, and disposal of building components (floors, roofs, walls, ceilings and windows). Our model comes with a site- and building-specific default parametrization for all buildings, but it is developed as a tool that allows architects and planners to adapt building and site data with specific information to increase the accuracy of the environmental assessment of the current buildings and future building-management scenarios. We applied the model to ten Swiss buildings and assessed a selection of building-management scenarios to illustrate the application of the tool. The results show that our model estimates fairly accurate values of thermal and ventilation heat transmittance, operational space heating demand, and operational and embodied climate-change impacts for the considered buildings. The detailed modeling results for the ten case study buildings outperformed the simplified version of the model with generic default values for material building composition (using age-grouped building archetypes), emphasizing the importance of adding detailed material information in building life cycle assessments. Therefore, a focus should be placed on obtaining accurate material inventories of buildings in future research. The here-developed model allows for integration of such detailed material inventories, overwriting the provided default values.

The impacts of future sectoral change on the greenhouse gas emissions of construction materials for Swiss residential buildings

Life Cycle Assessment (LCA) is a comprehensive method for evaluating building sustainability. However, most studies have relied on generic or national LCA databases, overlooking the systematic consideration of future scenarios and sectoral developments due to data and tool constraints. Moreover, there's a gap in providing a standardized workflow for such evaluations and understanding their impact on the greenhouse gas (GHG) emissions of buildings on a national level. Addressing these gaps, our study incorporates scenarios from two Integrated Assessment Models (IAMs), considering the future developments of the electricity, cement, and steel sectors, to assess embodied GHG emissions of Swiss residential buildings from 2015 to 2055. Our findings reveal that incorporating these future considerations can lead up to a 25% GHG emissions reduction by 2055 compared to 2015, primarily due to GHG emission reductions in concrete and brick as a result of these considerations. This is much less than the emissions reduction potential of some specific construction materials and far from the goal of net zero. It also underscores the importance of exploring alternative strategies for net-zero GHG emissions at the building stock level. Consequently, we present reproducible workflows using open-source tools and future versions of the Swiss national building LCA databases, offering a blueprint for similar future studies in other countries.

Biodiversity burdens in Spanish conventional and low-impact single-family homes

Biodiversity loss caused by housing is not a well-defined sector of environmental impact. This research quantifies effects on biodiversity of an average Spanish Single-Family House (SFH) with 180 m2 of built surface. The current Spanish SFH stock GWP amounts to 1.16 Gt CO2eq in a 50-year life cycle, 40 % of which is embodied in the building materials and the 60 % are emissions due to the use of the building. This stock also impacts with 10.2 Gt 1,4-DCB the land, water and human health. SFHs also drive 6052 species extinct in a 50 year life cycle, and account for 3.03 M years of life lost due to premature death or lived with a disability. Divided by the 16 M people living in Spanish SFHs, each one lost 0.19 years of their lives (68.1 days) due to their home's impacts on human health.The article compares a reference conventional building against three low-impact cases, to understand how different building techniques and materials influence environmental outcomes that keep biodiversity loss the lowest possible. Scenarios include a standard brick and concrete house as Scenario 0 (SC0, Base), a timber Passivhaus as Scenario 1 (SC1), a straw-bale house with renewable energies as Scenario 2 (SC2), and an earth bioclimatic house as Scenario 3 (SC3). An initial Global Warming Potential (GWP) analysis was performed to relate previous building Life Cycle Assessment (LCA) studies with biodiversity metrics. Three main biodiversity metrics; ecotoxicity (as midpoint indicator), biodiversity loss and damage to human health (both as endpoint indicators) have been considered.Compared to SC0 with 1292 kgCO2-eq·m−2 (516 embodied) of GWP, we found that SC1 emitted −47.0 % of that, SC2–41.4 % and SC3–80.9 %. Concerning ecotoxicity, where SC0 has 11,399 kg 1,4 DCB, the results are −27.9 % in SC1, −19.2 % in SC2, and −45.6 % in SC3. Regarding biodiversity loss, where SC0 has 7.54 E−06 species.yr·m−2, the impacts are −30.9 % in SC1, −32.6 % in SC2, and −58.6 % in SC3.Human health damage in SC0 being 3.37 E−03 DALY, has been reduced in the timber home (SC1) is −44.2 %, of the Straw SFH (SC2) −39.2 %, and of the earth house (SC3) −67.1 %.This article shows that with current existing technological solutions GWP could be reduced in −80.9 %, ecotoxicity in −45.6 %, biodiversity loss in −58.6 % and human health in −67.1 %. Spanish Single-Family Houses built in timber, earth or straw-bale are real alternatives to current cement traditional building.

LCA models in building industry practice - how do practitioners’ assumptions affect LCA results?

This study exemplifies uncertainties in Life Cycle Assessments (LCA) by investigating the results of nine building LCAs made by nine LCA practitioners. The study compares material quantities and Global Warming Potential (GWP) results of the nine LCAs before and after a review process. From the building LCAs before review, we identify several errors that significantly influence material quantities and GWP results. After correcting the errors, we still see notable differences in the material quantities and LCA results from the nine LCAs. The study proves a need for conducting thorough reviews to eliminate the most prominent errors in building LCAs and a need for uncertainty assessment as a standard practice.

Application of sensitivity analysis on building dynamic lifecycle assessment of GHG emissions: a French case study

This study presents a novel approach to simplify the dynamic life cycle assessment (DLCA) of buildings by identifying and prioritizing influential dynamic parameters (DPs) to improve building energy performance and reduce greenhouse gas emissions. Current life cycle assessment (LCA) methodologies lack temporal considerations, which can significantly impact a building’s environmental footprint over its multi-decade life span. We conducted an extensive literature review on DPs in DLCA, informing the creation of a multi-scenario parametric framework. A case study was then selected to apply the developed DLCA methodology and perform a global Sensitivity Analysis to pinpoint the most influential DPs on global warming potential. The DLCA framework integrates data from the French database for environmental product declarations and utilizes EnergyPlus simulations for operational emissions assessment. The study identifies ten DPs, revealing the most impactful ones to be industry and waste sector emissions reductions, building occupancy, and global warming. Additionally, we found minimal interactions between DPs, which facilitates the simplification of the DLCA process. This research enables building stakeholders to focus on a more selective set of parameters, enhancing the efficiency and accuracy of building life cycle assessments. Overall, our findings contribute to the continuous improvement of LCA methodologies and promote sustainable building practices.

Building within planetary boundaries: setting and assessing absolute sustainability targets at the building level

The planetary boundaries (PBs) are a widely used framework defining a “safe operating space” for environmental sustainability at the global level. However, they do not straightforwardly translate into indicators applicable in a building project. This paper proposes a procedure to set and assess absolute sustainability targets related to the PBs in a building project, exemplified in the case of Denmark. The first step is to ensure that the targets and the assessment method use comparable indicators. Common building life cycle assessment (LCA) tools use impact categories that do not directly match the PBs. Two options are considered to address this issue. Dedicated characterization factors can be used to convey LCA results in indicators consistent with the PBs. Alternatively, PB targets can be converted into LCA impact categories. Then, several distributive justice principles are reviewed to allocate a share of planetary sustainability targets to an individual country, to the housing sector within that country, and to an individual project. We argue that principles that conserve existing unsustainable paradigms are not appropriate to set planetary sustainability targets, and propose a novel approach for sectorial allocation based on sufficientarianism and “decent living” scenarios. Finally, challenges related to the assessment of these targets are highlighted. In particular, the paper draws attention to differences in system boundaries between the LCA and the targets.

Carbon handprint – a review of potential climate benefits of buildings

ABSTRACT As buildings account for 39% of greenhouse gas emissions, the building sector is essential for pursuing carbon neutrality. Carbon footprints of buildings are currently emerging in the legislation of European countries. However, the concept of carbon neutrality calls for both reducing emissions and increasing carbon sinks and storages. The concept of ‘carbon handprint’ describes potential climate benefits that are related to a product, service, or an organization. Although an increasing body of scientific and professional literature exist on the concept, there are no standards for guiding its quantification in the context of buildings. Furthermore, examples demonstrating the potential of building related carbon handprints are still scarce. In this article, we examine and evaluate different climate benefits that can be utilized in life-cycle assessment of buildings. We test them through a case study of a wooden apartment building. Our results indicate that methodologically most mature handprints include carbon storage in bio-based products, carbonation of concrete, surplus energy, as well as reuse, recycling, and energy recovery. In our study, the relative size of the calculated handprints varies considerably between 39% and 87% of the building’s footprint. However, uncertainties and methodological development needs should be addressed in the standardization work.

A statistical analysis of life cycle assessment for buildings and buildings’ refurbishment research

This study aims to examine the literature related to environmental Life Cycle Assessment (LCA) for buildings and buildings' refurbishment from 1994 to 2022 by implementing a statistical analysis based on 'Web of Science' databases. LCA is viewed as a consolidated process that measures the environmental performance of buildings and their services, aiming to address the potential environmental impacts over the life cycle of buildings. A total of 1336 retrieved journal publications for LCA for buildings and 169 journal publications for LCA in building refurbishment. The articles' patterns were investigated in terms of subject categories, journals, countries, and the most highly cited articles. The findings reveal that LCA publications for buildings and building refurbishment have increased over the period 1994–2022, with China being the leading country contributing to the largest number of articles and possessing the most significant influence, followed by the USA for LCA in buildings. While Portugal is the leading country, followed by Italy, for LCA Buildings' Refurbishments. 97.08% of the publications were written in English, 2.04% in German, and 0.68% in Spanish. French and Japanese were the remaining languages, each with one publication, accounting for 0.2% of the 1336 building LCA publications. In contrast to refurbishment, LCA publications were written in only two languages, English (98.7%) and German (1.3%). Results show that the subject area differs depending on the type of LCA publication, with building LCA focusing on construction engineering while refurbishment focused on environmental topics. According to the IF, the most influential journal was renewable & sustainable energy for buildings and refurbishment LCA. However, journal distribution within LCA is still limited, and assessment methods and theme analysis still need to catch up with a clear gap in LCA in environmental impact mitigation and analysis methodologies, which will be a prominent direction of future building LCA research.

Quantifying acoustic performance and embodied carbon of acoustic solutions for mass timber buildings: Comparing common approaches around the globe

As mass timber continues to increase in popularity as a building method to shifting away from high embodied carbon concrete structures to utilize wood as a renewable and lower embodied material. As whole building life cycle assessments (LCA) become more essential in meeting environmental emissions targets and qualifying for sustainability linked financing, quantifying the embodied carbon of both the structure and all other elements is necessary. The acoustic challenges of mass timber have been well documented and studied in previous works with a range of solutions now commonly utilized. Like most elements of construction, regionality results in different techniques being more popular and practical in different parts of the world. This work will compare the airborne and structure borne sound transmission and associated embodied carbon of four common acoustic designs for mass timber construction: floating concrete toppings, isolated board and batten floor systems, isolated dry floor linings, and raised access floors.

Enhancing whole building life cycle assessment through building information modelling: Principles and best practices

Enhancing whole building life cycle assessment through building information modelling: Principles and best practices