Harpa Birgisdottir

Aalborg University

Purpose The built environment has demonstrated the limited nature of applications of consequential LCA (LCA), whereas attributional LCA (ALCA) is applied in most situations. Therefore, this study aims to clarify the contexts in which CLCA might be applied and the state of CLCA on buildings by examining the following research questions: (i) How are...

Given the current climate crisis countries and sectors need to set targets and address reduction potentials for their greenhouse gas (GHG) emissions. The current use of bottom-up benchmarks for the building sector enables relative sustainability comparisons. However, we must start relating the environmental performance of buildings to science-based...

Wood and other bio-based building materials are often perceived as a good choice from a climate mitigation perspective. This article compares the life cycle assessment of the same multi-residential building from the perspective of 16 countries participating in the international project Annex 72 of the International Energy Agency to determine the ef...

Buildings’ construction and operation are major contributors to global greenhouse gas (GHG) emissions, and the substantial reduction of GHG emissions across their full life cycle is required to enable meeting international climate targets. For effective climate change mitigation - as recent studies have shown - a special focus has to be put on lowe...

Buildings account for 40% of global Greenhouse gas (GHG) emissions. In heating-dominated climates, most building-related emissions originate from building stock operational energy, especially from buildings constructed before energy requirements were introduced. Renovation can mitigate operational emissions, however, materials should be included to...

The increasing awareness on climate issues in the built environment places a greater responsibility on the different actors to map the building emissions, reduce and optimise the use of materials, and thereby lower the environmental footprint. With several countries enforcing legally binding CO 2 limits to assess and benchmark the negative environm...

In a context of digitalization and increasing quality requirements, the building sector is facing an increasing level of complexity regarding its design process. This results in a growing number of involved actors from different domains, a multitude of tasks to be completed and a higher degree of needed expertise. New buildings are also required to...

Buildings can potentially be carbon sinks by use of wood under correct circumstances because wood sequesters CO 2 i.e., biogenic carbon, from the atmosphere by photosynthesis during growth. Consequential life cycle assessment (CLCA) works as a decision support tool to assess consequences from a change in demand by including only the processes that...

The built environment is responsible for reaching global climate targets such as the Paris agreement and carbon neutrality in 2050. It is a well-known fact that buildings stand for 37% of global greenhouse gas (GHG) emissions, where 10% is due to emissions from the production of building materials, while the remaining 27% comes from energy consumpt...

Life cycle assessment (LCA) is increasingly being used as a tool by the building industry and actors to assess the global warming potential (GWP) of building activities. In several countries, life cycle based requirements on GWP are currently being incorporated into building regulations. After the establishment of general calculation rules for buil...

Immense amounts of natural resources are consumed and processed by the construction sector every year resulting in a significant climate impact. In return, the resource and environmental value of these resources is lost due to the vast amounts of construction and demolition waste (C&DW) that is down-cycled. Thus, the potential of transitioning the...

With a growing building stock and initiatives such as the European “renovation wave” which aims to double the annual energy renovation rates in the next ten years, environmental assessment of building refurbishment becomes still more important. Using standardized environmental assessment methods such as life cycle assessment (LCA) on renovation pro...

The Circular Economy (CE) is gaining traction throughout all industries and nations globally. However, despite several attempts, no one-off solutions for assessing the benefits and pitfalls of CE have been established, and neither have any measures with which to determine decisions. In line with this general observation, the Built Environment (BE)...

The purpose of this project is to examine the break-even in greenhouse (GHG) emissions between material use and energy saving in renovations. The project includes the interventions thermal insulation, windows and photovoltaics (PV). Furthermore, the project seeks to illustrate opportunities as well as obstacles when employing this type of assessmen...

Buildings play a vital role in reaching the targets stated by the Intergovernmental Panel on Climate Change to limit global warming to 1.5 degrees. Increasing the use of wood in construction is a proposed upcoming strategy to reduce the embodied greenhouse gas emissions of buildings. This study examines existing life cycle assessments of wooden bui...

The use of wood and timber products in the construction of buildings is repeatedly pointed towards as a mean for lowering the environmental footprint. With several countries preparing regulation for life cycle assessment of buildings, practitioners from industry will presumably look to the pool of data on wood products found in environmental produc...

Transitioning to a circular built environment can reduce the environmental impacts, resource consumption and waste generation emanating from buildings. However, there are many options to design circular building components, and limited knowledge on which options lead to the best environmental performance. Few guidelines exist and they build on conv...

The climate debate necessitates reducing greenhouse gas emissions from buildings. A common and standardized method of assessing this is life cycles assessment (LCA); however, time and costs are a barrier. Large efficiency potentials are associated with using data from building information models (BIM) for the LCA, but development is still at an ear...

Whole life carbon assessment of 60 buildings - Possibilities to develop benchmark values for LCA of buildings assesses the hitherto largest number of building cases collected in Denmark with regard to GWP. As part of the objective to reduce global greenhouse gas emissions, in recent years there has been great focus in the building and construction...

Buildings are a major cause of global resource consumption, greenhouse gas (GHG) emissions and other impacts on the environment, originating from both operational energy and material use. Informed design decisions can help mitigate potential impacts on the environment, by the use of life cycle assessment (LCA) in the early project stages. In order...

Circular Economy (CE) can help reduce the building industry's immense environmental impact. Life cycle assessment (LCA) can facilitate CE decision-making by identifying the largest environmental impact reduction opportunities throughout a building's life cycle, but it does not suffice in a design situation. Thus, aggregated LCA knowledge is needed....

Introduction: The international research project IEA EBC Annex 72 investigates the life cycle related environmental impacts caused by buildings. The project aims inter alia to harmonise LCA approaches on buildings. Methods: To identify major commonalities and discrepancies among national LCA approaches, reference buildings were defined to present a...

Introduction: Design practitioners’ knowledge and understanding of LCA is crucial for the necessary transition to decarbonisation of the built environment, as well as for lowering other environmental impacts. Recently, the Nordic councils of ministers suggested enhancing cooperation and harmonization within the use of LCA in the built environment i...

Introduction: In building LCAs, the calculations are carried out over a chosen reference study period (RSP), which is commonly set around 50-60 years. When developing the Danish LCA method for DGNB certification, and later for the preparation of the voluntary sustainability class for the building code, longer RSP’s were suggested by technical commi...

Introduction: Buildings are responsible for 39 % of CO2 emissions in the world and have the largest consumption of natural resources. The concept of Circular Economy can be used as an approach for mitigating environmental impact in this sector. Circular economy in the built environment can be implemented on a building level through preservation ins...

Introduction. The building sector consumes 40% of resources globally, produces 40% of global waste and 33% of greenhouse gas emissions. The transition towards a Circular Economy (CE) in the built environment is vital to achieve the Sustainable Development Goals (SDGs) of climate action and responsible consumption and production. Metrics are needed...

In the face of the unfolding climate crisis, the role and importance of reducing Greenhouse gas (GHG) emissions from the building sector is increasing. This study investigates the global trends of GHG emissions occurring across the life cycle of buildings by systematically compiling life cycle assessment (LCA) studies and analysing more than 650 bu...

Transitioning the built environment to a circular economy (CE) is vital to achieve sustainability goals but requires metrics. Life cycle assessment (LCA) can analyse the environmental performance of CE. However, conventional LCA methods assess individual products and single life cycles whereas circular assessment requires a systems perspective as b...

This chapter considers how circularity is being, and might be, approached and achieved within the built environment. Three case studies illustrate the current situation. The first case address life cycle assessment (LCA) in measuring circularity, showing that while LCA encourages recycling it gives little support to Design for Disassembly. The seco...

While the operational energy use of buildings is often regulated in current energy saving policies, their embodied greenhouse gas emissions still have a considerable mitigation potential. The study aims at developing a multi-objective optimization method for design and renovation of buildings incorporating the operational and embodied energy demand...

Target values for creating carbon budgets for buildings are important for developing climate-neutral building stocks. A lack of clarity currently exists for defining carbon budgets for buildings and what constitutes a unit of assessment—particularly the distinction between production- and consumption-based accounting. These different perspectives o...

Use of life cycle assessment (LCA) in choice of road corridor could reduce environmental impacts of traffic and infrastructure. This paper explores how the LCA model LICCER, designed to compare life cycle climate impact and energy use of alternative road corridors, fulfills practitioners’ requirements concerning data availability and usefulness for...

The concept of circular economy has been introduced as a strategy to reduce the greenhouse gas (GHG) emissions from buildings and mitigate climate change. Although many innovative circular solutions exist, the business model is challenged by a lack of environmental data on the circular solutions, and thus the potential benefits are not verifiable....

The considerable environmental impacts, resource consumption and waste generation emanating from buildings are a cause of great concern and political attention. Interest in the circular economy (CE) concept of slowing, narrowing and closing material loops through CE strategies (reuse, repair, refurbish, recycle and recover) has grown in recent year...

This study presents the environmental life cycle assessment of four low carbon design strategies applied in Danish, architectural practice. The subject of analysis is a set of five buildings erected within the same constrictions in terms of floor area, energy performance and construction costs. The tested design strategies were: use of recycled mat...

Buildings are major sources of greenhouse gas (GHG) emissions and contributors to the climate crisis. To meet climate-change mitigation needs, one must go beyond operational energy consumption and related GHG emissions of buildings and address their full life cycle. This study investigates the global trends of GHG emissions arising across the life...

I rapporten Livscyklusvurdering for cirkulære løsninger med fokus på klimapåvirkning etableres der et første bud på dokumentation af cirkulære byggematerialers klimapåvirkning. I byggeriet har der i de senere år været fokus på at finde holdbare løsninger til at minimere bygningers miljøbelastning og ressourcetræk. Her indgår ”cirkulær økonomi” som...

The purpose of this study is to investigate absolute environmental sustainability in the built environment, by assessing whether contemporary environmentally optimized approaches to building design, with their associated consumption of resources and subsequent emissions, can be considered within the carrying capacity of Earth Systems. A life cycle...

The building sector is of major concern when seeking to reduce the environmental impact of our society. A common tool often used in certification systems for quantification of environmental impacts is Life Cycle Assessments (LCAs). LCAs are traditionally used for relative comparisons, i.e. to assess whether one product or service performs better th...

As circular economy (CE) is becoming a growing focus in the building industry due to the industries large resource consumption, waste production and environmental impacts a better understanding of buildings material composition, resource consumption and resulting environmental performance becomes increasingly important in order to support the trans...

Purpose The 71st LCA forum was held on 18 June 2019 in Zurich, Switzerland, to discuss the current status and future plans of environmental benchmarking for buildings in view of the 1.5 °C target stipulated in the Paris Agreement. The Paris Agreement requires a significant reduction in greenhouse gas emissions, in fact net zero by 2050. One of the...

Increasing building demands from a growing world population puts enormous pressure on natural resources. Management of resource consumption and environmental impacts is therefore vital to secure contemporary and future well-being and progress. Circular Economy (CE) is perceived as an industrial economy model potentially minimizing resource consumpt...

The IEA EBC Annex 72 focuses on the assessment of the primary energy demand, greenhouse gas emissions and environmental impacts of buildings during production, construction, use (including repair and replacement) and end of life (dismantling), i.e. during the entire life cycle of buildings. In one of its activities, reference buildings (size, mater...

There is an increasing demand for Life Cycle Assessment (LCA) as a method for environmental impact and resource assessments of buildings. At early design stages, where major design decisions are made, the potential for improving the environmental performance using LCA is greatest. However, detailed building information is usually not available at t...

Investment decisions for buildings made today largely determine their environmental impacts over many future decades due to their long lifetimes. Such decisions involve a trade-off between additional investments today and potential savings during use and at end of life - in terms of economic costs, primary energy consumption, greenhouse gas emissio...

Life Cycle Assessment (LCA) is used and accepted as a method to assess environmental impacts and resource use of buildings. In practice, LCA is typically used in stages where the design of the building is already finalized. However, LCA-calculations from early design stages can be used actively in design and optimization of the building. One of the...

This paper publishes the results from a major five year International Energy Agency research project which investigated the reduction of embodied energy and greenhouse gas emissions over the whole life (‘cradle to grave’) of buildings. Annex 57 collated and analysed over 80 detailed quantitative and qualitative building case studies from the partic...

In the autumn of 2014, the Danish government presented a national strategy for the building sector. Sustainability was mentioned as one of five focus areas for the future political work within the sector. Subsequently, the development of a national Life Cycle Assessment tool for buildings was initiated, and the first version of LCAbyg was launched...

This study provides LCA reference benchmarks for residential buildings in Northern Italy and Denmark. Furthermore, the benchmark derivation process is analysed to highlight the trade-offs that relate to the methodological choices made by benchmark developers, considering the objectives of the stakeholders. Reference benchmarks for the two contexts...

This paper investigates how the EU Level(s) can be adopted in Denmark. The study is limited to life cycle assessment (LCA) requirements within the Level(s) scheme. As a measure for the Danish building sector's LCA practice, the specifications for LCAbyg, the official Danish building LCA tool, is used. In 2017, the European Commission's Joint Resear...

Within the ReSOLVE framework, the concept of 'Looping' materials in an efficient way is a crucial theme to ensure environmental sustainability of circular economy. This paper investigates how current calculation practice of building LCA from the EN 15804/15978 standards affects the global warming potential (GWP) of building designs where material l...

The availability of sustainable (or green) building certifications schemes is constantly increasing and it is not always easy to understand how the schemes on the market differentiate from each other. The purpose of this study is to create a better dialog between client and consultant in relation to building certification systems. Here it is releva...

As the construction industry consumes vast amounts of natural resources and in return produces large waste quantities, interest in circular economy has emerged as the means to reduce sector specific environmental impacts meanwhile ensuring continued economic growth. Life cycle assessment is a scientifically based and ISO standardized method for ass...

The building industry contributes to resource scarcity by consuming vast amounts of natural resources and produces in addition large amounts of waste, both contributing to a considerable portion of the environmental impacts induced by the demands of a growing world population. Manufacturing of most building materials require large amounts of materi...