Sustainability Tools for the Assessment of Construction Materials and Buildings

The construction industry, contributing to about 9% of the European Union's GDP, has played a significant influential role in the development of the energy strategy of Europe and is also anticipated to be an important contributor in its successful implementation (EC, 2016). Holistic sustainability assessment tools that are able to evaluate and optimise the environmental performance of construction materials and buildings are considered a key for the development of advanced building designs and use of sustainable building materials and elements and green energy- efficient systems that will raise high the sustainability level of the European built environment. The aim of this work is the thorough explanation of the standardised LCA methodology, and the introduction of the approach of EcoHestia, a comprehensive building sustainability assessment tool. In view of that, the current legislation addressing the construction industry, as well as the state-of-the- art Life Cycle Assessment (LCA) tools that are used for the sustainability assessment and optimisation of construction materials and buildings are also presented. Furthermore, through the employment of EcoHestia, the environmental impact of a case study building is defined, also providing a detailed breakdown of the contribution of each construction material in the overall environmental performance of the building. The analysis of the results has not only determined on the construction materials of the building that are most harmful to the natural resources and the environment, but also showcased the effectiveness and added value of utilizing this approach in moving forward towards a more sustainable green building sector

Integration of Building Information Modelling (BIM) and Life Cycle Assessment (LCA) for sustainable constructions

The construction industry and the scientific community continue to seek for innovative approaches that can estimate the level of sustainability to be achieved at the end of the project from the early design stages. One of the tools developed for this purpose is Building Information Modelling (BIM), which represents the state- of- the- art tool for bringing together different expertise and achieving optimal designs at an early design stage for the maximisation of their impact. However, the level of the prospect of this tool has not been fully exploited. This paper integrates BIM with an established methodology for assessing a product's or a system's environmental performance- Life Cycle Assessment (LCA)- in an attempt to maximise the benefits from this synergy and achieve the most sustainable constructions. The impact from the integration of these two valuable tools is presented for a water supply system using case studies for a range of different materials. Comparison of a modern Vernetztes Polyethylen (VPE) water supply system against two systems made from traditional materials (steel and copper) was made. The results of this study show that a VPE water supply system performs 87% better than the steel system, and 88% better than a copper water supply system in terms of climate change, while the carbon dioxide emissions released during the production of a VPE system are almost the one tenth of traditional materials water supply systems

Numerical data on heat flux of a novel controlled-temperature double skin façade

Hourly heat flux for variant boundary conditions of a novel controlled-temperature double skin façade (DSF) building element in a two- dimensional time- dependent study was determined. The building element is subjected to boundary conditions, characterizing different orientations (azimuth 0°, 90°, 180°, 270°) and climatic conditions of the four seasons. This data article provides detailed numerical data on the hourly heat flux, temperatures attained at the exterior and within the building element for six different geometries and for the variant boundary conditions under study. The external boundary conditions were determined with the use of the PVGIS tool, corrected in accordance to the sol-air temperature equation. The numerical simulation studies were performed with the use of the computational fluid dynamics (CFD) tool Comsol Multiphysics [2]

Boundary Conditions Accuracy Effect on the Numerical Simulations of the Thermal Performance of Building Elements

Numerical simulation is widely used in the field of computational building physics for the definition of the thermal performance of building elements. An integral component of numerical simulation using finite elements is the boundary conditions, which, in the case of simulating the thermal performance of a building element, are usually expressed in terms of the external surface temperature as a function of time. The purpose of this study is to examine the effect of the accuracy of the boundary conditions on the thermal performance simulation of building elements. The assumption that the temperature versus time is a sinusoidal function, applied in standard methods, is comparatively assessed with the actual function for diverse climatic conditions using finite elements simulation. The findings of the analysis indicate that the sinusoidal function fails to accurately simulate real boundary conditions. The originality of this study lies within the adoption of a signal reconstruction algorithm, which follows a novel approach by reconstructing the actual temperature versus time signal for the simulation of the actual boundary conditions

Phase change materials (PCMs) integrated into transparent building elements: A review

Phase change materials (PCMs) represent an innovative solution that can contribute to the improvement of the energy performance of buildings. Recently a trend towards integrating PCMs into transparent envelope components is observed. This study aims to present the main solutions proposed in the literature for applications in the past few years for PCMs integrated into transparent buildings elements. The temporal development of this application as well as the fundamental principles of its operation is described in detail. The concept of the existing transparent PCM systems is presented, and the rationale of selecting appropriate materials is discussed. This is followed by the current practices in testing the thermal performance of transparent PCMs. The future trends in terms of the current barriers and the potential improvements are discussed. To this end the future technologies of transparent PCMs are also considered

Life Cycle Assessment of concrete manufacturing in small isolated states: the case of Cyprus

Life Cycle Assessment (LCA) is an effective and valuable methodology for identifying the holistic sustainable behaviour of materials and products. It is also useful in analysing the impact a structure has over the course of its life cycle. Currently, there is no sufficient knowhow regarding the life cycle performance of building materials used in the case of small isolated states. This study focuses on the LCA of the production of concrete for the investigation of its environmental impact in isolated island states, using the case of Cyprus as an example. Four different scenarios for the production of 1 tonne of concrete are examined: (i) manufacturing of concrete by transporting raw materials from different locations around the island, (ii) manufacturing of concrete using alternative energy resources, (iii) manufacturing of concrete with reduced transportation needs, and (iv) on-site manufacturing of concrete. The results, in terms of environmental impacts of concrete produced, indicated that the use of renewable electricity instead of fossil-fuelled electricity in isolated states can drastically improve the environmental performance of the end product. Also, the minimisation of transportation distances and the use of locally available resources can also affect, to a degree, the environmental impact of concrete production. Abbreviations: AP: Acidification Potential; CRC: Completely Recyclable Concrete; GWP: Global Warming Potential; HFO: Heavy Fuel Oil; LCA: Life Cycle Assessment; LCI: Life Cycle Inventory; LCIA: Life Cycle Impact Assessment; MPA: Mineral Products Association; ODP: Ozone Depletion Potential; POCP: Photochemical Ozone Creation Potential; PV: Photovoltaic

Key Performance Indicators (KPIs) approach in buildings renovation for the sustainability of the built environment: A review

[EN] The reduction of the energy consumption and the improvement of the indoor climate issues when renovating can achieve added benefits including reduced outlay on government subsidies, and improved health due to less air pollution and a better indoor quality conditions and improved worker productivity. This is the essence of assessing the level of sustainability of building renovation projects. The functionality of the Key Performance Indicators (KPIs) approach has made it one of the most popular and valuable tools among recorded literature regarding the measurement of the level of sustainability of construction projects. The aim of this paper is to review the previous studies that employed the KPIs approach in buildings renovation for the measurement of the sustainability of the built environment. This work provides a brief foreword regarding the state of the art in building renovation projects, as well as the suitability of the application of the KPIs approach for the assessment of the level of sustainability in such projects and analyzes the results of the literature review. The future trends in building assessment methodologies for sustainability purposes are also presented, while some significant conclusions are also given based on the identification of the existing gaps of the specific fieldAuthors are indebted to COST Action TU 1104 "Smart Energy Regions" for supporting this work.Kylili, A.; Fokaides, PA.; López Jiménez, PA. (2016). Key Performance Indicators (KPIs) approach in buildings renovation for the sustainability of the built environment: A review. Renewable and Sustainable Energy Reviews. 56:906-915. doi:10.1016/j.rser.2015.11.096S9069155

Thermal performance of brick and stone masonry: Cumulative heat flux dataset for main orientations and under diverse seasonal conditions

This dataset consists of the hourly heat flux for four seasons and orientations of 15 different construction configurations of brick and stone masonry combined with insulation system solutions. The analysis was conducted with the use of Finite Element Modelling (FEM). The development of the models and the investigation of their thermal performance was conducted with the use of thermal modelling and numerical simulation analysis with COMSOL Multiphysics. For this purpose, a transient 2D multi- dimensional, time- dependent simulation model on finite elements was developed. The governing equations of heat transfer were considered as well as the convection and radiation heat transfer coefficients in accordance to the ISO 6946:2017 [1]

Lignin valorisation: Life Cycle Assessment (LCA) considerations for enabling Circular Bioeconomy

Lignin constitutes the sole renewable aromatic resource found in abundance on Earth and does not call into question the ethics of diverting land from food to energy production. In view of that, the potential of lignocellulosic biomass in promoting the Circular Economy and Bioeconomy concepts in future biorefinery operations is widely acknowledged. Biorefineries can convert lignocellulosic biomass into high-value products, lessen their environmental effect, and hasten the advent of a sustainable and renewable future by incorporating cutting-edge technologies and doing thorough Life Cycle Assessment analysis. However, converting lignin into added-value products is a challenging field from technological, environmental, and economic perspectives. This work set out to determine the most critical environmental aspects expected to provide reliable evidence in support of lignin valorisation routes that enable the production of value-added products and bioenergy. Findings provide the necessary knowledge for decision-making in biorefineries aligned with the Circular Bioeconomy concept, like how decision-making relating to future biorefineries is facilitated. Highlights Environmental burdens of lignin-derived products valorisation due to complex lignin structure A limited number of LCA studies on the valorisation of lignin to added-value products Future lignin-based biorefineries development should be assessed using holistic, sustainable approaches LCA methodologies on environmental performance of promising lignin valorisation routes Controversial aspects of lignin valorisation under the Circular Bioeconomy concept Raised concerns as a result of the lignin fraction expected high demand Identified controversial environmental aspects linking lignin valorisation to adverse impact

Lignin valorisation: Life Cycle Assessment (LCA) considerations for enabling Circular Bioeconomy

Lignin constitutes the sole renewable aromatic resource found in abundance on Earth and does not call into question the ethics of diverting land from food to energy production. In view of that, the potential of lignocellulosic biomass in promoting the Circular Economy and Bioeconomy concepts in future biorefinery operations is widely acknowledged. Biorefineries can convert lignocellulosic biomass into high-value products, lessen their environmental effect, and hasten the advent of a sustainable and renewable future by incorporating cutting-edge technologies and doing thorough Life Cycle Assessment analysis. However, converting lignin into added-value products is a challenging field from technological, environmental, and economic perspectives. This work set out to determine the most critical environmental aspects expected to provide reliable evidence in support of lignin valorisation routes that enable the production of value-added products and bioenergy. Findings provide the necessary knowledge for decision-making in biorefineries aligned with the Circular Bioeconomy concept, like how decision-making relating to future biorefineries is facilitated. Highlights Environmental burdens of lignin-derived products valorisation due to complex lignin structure A limited number of LCA studies on the valorisation of lignin to added-value products Future lignin-based biorefineries development should be assessed using holistic, sustainable approaches LCA methodologies on environmental performance of promising lignin valorisation routes Controversial aspects of lignin valorisation under the Circular Bioeconomy concept Raised concerns as a result of the lignin fraction expected high demand Identified controversial environmental aspects linking lignin valorisation to adverse impacts