High-resolution and localized parametric embodied impact calculator of PV systems

Buildings are responsible for a large amount of greenhouse gas emissions in the world. In order to decarbonize the electricity grid and reduce the environmental impact of the building stock, photovoltaic panels can be installed. However, in order to assess the environmental impact of PVs, the whole life cycle has to be considered including embodied emissions. Several options for photovoltaics exist on the market or are under development including silicon-based panels, thin films, and third generation panels. Currently, many configurations of the panels exist making it difficult to estimate the embodied impact. The goal of this paper is to close this gap by providing a parametric PV carbon calculator for designers and decision-makers. In this study, the embodied impact of different PV types and configurations is assessed. First, the life cycle inventories data and bill of quantities for different generations\u27 panel types are gathered. Second, life cycle impact assessment is performed. The results of the analysis are presented in a form of a software application allowing users to select the panel\u27s composition, e.g., frame and glass type, cell type, encapsulant, etc. The developed application will assist in understanding the impact of choices made in regards to PV systems and will support engineers and architects in the selection of the photovoltaic panels from embodied impact perspective

A data-driven parametric tool for under-specified LCA in the design phase

Life Cycle Assessment (LCA) is increasingly applied to evaluate the environmental performance of buildings. However, current tools for building LCA require detailed information not available in the decisive early design stages. As a result, LCA is usually applied as post-design evaluation and not used to improve the building design. The goal of this paper is to adapt the method of structured under-specified LCA to the Swiss context and implement it in a design-integrated tool. The users of the tool should be able to get a complete estimation of the life cycle impact based on very few inputs, such as building type, intended use and structural system. In addition, the tool should allow to replace these assumptions with more detailed information step by step throughout the design process. The paper describes the development of a structured database and a parametric tool. Furthermore, it exemplifies the intended workflow during the design process on a building design. The presented approach can be scaled up and adapted to the needs of other national contexts in the future. It facilitates environmental performance optimisation of buildings and supports making use of the big potential the building sector has regarding contributing towards climate action (UN SDG 13)

Statistical method to identify robust building renovation choices for environmental and economic performance

Building renovation is urgently required to decrease the energy consumption of the existing building stock and reduce greenhouse gas emissions coming from the building sector. Selecting an appropriate renovation strategy is challenging due to the long building service life and consequent uncertainties. In this paper, we propose a new framework for the robust assessment of renovation strategies in terms of environmental and economic performance of the building\u27s life cycle. First, we identify the possible renovation strategies and define the probability distributions for 74 uncertain parameters. Second, we create an integrated workflow for Life Cycle Assessment (LCA) and Life Cycle Cost analysis (LCC) and make use of Sobol’ indices to identify a prioritization strategy for the renovation. Finally, the selected renovation scenario is assessed by metamodeling techniques to calculate its robustness. The results of three case studies of residential buildings from different construction periods show that the priority in renovation should be given to the heating system replacement, which is followed by the exterior wall insulation and windows. This result is not in agreement with common renovation practices and this discrepancy is discussed at the end of the paper

Application and validation of a method to assess the energy reduction and environmental impact of renovation alternatives

The renovation of residential stock is one of the most promising areas, in terms of energy reduction, because these buildings are highly inefficient and represent the largest part of the building stock. However, the environmental impact assessment over the life cycle of building renovation is rare. It is more common to develop an assessment for new buildings. This study presents a method that combines the evaluation of the benefits of renovating residential buildings, considering cost, energy and environmental benefits using Life Cycle Assessment (LCA). The method is based on 3 stages of development. First, the database of energy certificates, costs and LCA was analysed. The second step is to develop a workflow in Rhino/Grasshopper/E-Plus to automatically model a residential building and feed the simulation model with the data obtained from the databases. Finally, a simulation campaign was carried out to obtain an optimal renovation package, minimising energy consumption and environmental impact. The research was carried out in a case study in Uddevalla, Sweden. The residential building has different measurements including energy consumption data before and after renovation. This was used to validate the proposed methodology. The validation shows that accurate results are achievable with potential for mass application

What is the optimal robust environmental and cost-effective solution for building renovation? Not the usual one

Buildings are responsible for a large share of CO2 emissions in the world. Building renovation is crucial to decrease the environmental impact and meet the United Nations climate action goals. However, due to buildings’ long service lives, there are many uncertainties that might cause a deviation in the results of a predicted retrofit outcome. In this paper, we determine climate-friendly and cost-effective renovation scenarios for two typical buildings with low and high energy performance in Switzerland using a methodology of robust optmization. First, we create an integrated model for life cycle assessment (LCA) and life cycle cost analysis (LCCA). Second, we define possible renovation measures and possible levels of renovation. Third, we identify and describe the uncertain parameters related to the production, replacement and dismantling of building elements as well as the operational energy use in LCCA and LCA. Afterwards, we carry out a robust multi-objective optimization to identify optimal renovation solutions. The results show that the replacement of the heating system in the building retrofit process is crucial to decrease the environmental impact. They also show that for a building with already good energy performance, the investments are not paid off by the operational savings. The optimal solution for the building with low energy performance includes the building envelope renovation in combination with the heating system replacement. For both buildings, the optimal robust cost-effective and climate-friendly solution is different from the deep renovation practice promoted to decrease the energy consumption of a building

Improving the collaboration between architects and energy consultants through design-integrated early BIM-tools

There is a lack of optimization of buildings towards energy performance in early design stages in practice. Interviews with architects and energy consultants showed that one reason is the inefficient communication between these two groups. This paper investigates how a design-integrated early-BIM tool can improve the relation between architects and energy consultants to support an optimization process in early design stages and facilitate issuing energy performance certificates. Two case studies show that the early-BIM tool provides meaningful results for the architects involved and can reduce the input time for energy consultants by 50%. Furthermore, the simple 3D model functions as boundary object between the two groups and supports the collaboration

Review of visualising LCA results in the design process of buildings

Life Cycle Assessment (LCA) is increasingly used for decision-making in the design process of buildings and neighbourhoods. Therefore, visualisation of LCA results to support interpretation and decision-making becomes more important. The number of building LCA tools and the published literature has increased substantially in recent years. Most of them include some type of visualisation. However, there are currently no clear guidelines and no harmonised way of presenting LCA results. In this paper, we review the current state of the art in visualising LCA results to provide a structured overview. Furthermore, we discuss recent and potential future developments. The review results show a great variety in visualisation options. By matching them with common LCA goals we provide a structured basis for future developments. Case studies combining different kinds of visualisations within the design environment, interactive dashboards, and immersive technologies, such as virtual reality, show a big potential for facilitating the interpretation of LCA results and collaborative design processes. The overview and recommendations presented in this paper provide a basis for future development of intuitive and design-integrated visualisation of LCA results to support decision-making.ISSN:0360-1323ISSN:0360-132

IEA EBC Annex 72: Assessing Life Cycle Related Environmental Impacts Caused by Buildings: Guidelines for design decision-makers:Energy in Buildings and Communities Technology Collaboration Programme

The purpose of this report is to provide support to the design decisions-makers during the design process. For each of the defined design step decision the important topics to consider were identified, the key stakeholders are declared and the purpose of LCA at the selected design step is defined. The report covers: The definition of the design steps, the definition of the tasks in each design step and an overview of the relevant milestones for performing LCA; An overview of the systematic building decomposition methods and the appropriate levels at each design step; An overview of the tools that can be used for LCA and a selection process for choosing the right LCA tool. A special emphasize is given to the topic of Building Information Modelling (BIM), how the BIM tools can facilitate the LCA assessment and what information should be implemented in the BIM model; Strategies on how to reduce the design-related uncertainties; An overview of the visualization of the LCA results and which are appropriate in the selected design steps