Embodied Energy Savings Research Articles

Environmental performance assessment: A comparison and improvement of three existing social housing projects

The energy consumption of buildings accounts for 22% of total global energy use and 13% of global greenhouse gas emissions. In this context, this study aims to evaluate the environmental performance of three social housing designs located in emerging economies by analysing sustainability indicators adopting different technical solutions. The analysis incorporates eleven construction strategies to improve the environmental performance of the buildings. The performance assessment is analysed by using EDGE (Excellence in Design for Greater Efficiencies) Methodology. Therefore, this study aims to help identify the construction strategies, with the aim of improving the operational energy performance (kWh/year/m 2 floor), operational CO 2 emissions (tCO₂eq/Year/m 2 floor), embodied energy (MJ/m 2 floor) and operational water consumption of housing (m3/year/m 2 floor). The results showed that when the technical measures are implemented, the energy demand decreases by 38.52% in Case A, 19% in Case B, and 41% in Case C. The embodied energy savings in materials in Case A 3%, Case B 0% and Case C 36% Regarding water consumption, the demand decreases by 46%, 4%, and 12% in Case A, B, and C respectively. • Strategies to improve the environmental building performance are identified. • Key implications to achieve green renovation in existing social housing design. • A contribution to the housing environmental performance assessment is presented.

Selection of Sustainable Materials for Energy Savings of Infrastructure-Transportation Project in Ahmedabad, India Using BIM and FCM

This study aims to develop a methodology for the selection of sustainable building materials for the reduction of embodied and operational energy for a complex infrastructure transportation project, i.e., elevated metro rail station of Ahmedabad, India by application of building information modelling (BIM) and factor comparison method (FCM). Evaluation of the alternative building materials and designs to obtain the best energy efficiency has been carried out using Revit Architecture 2018 and Green Building Studio. The achieved average embodied energy savings is about 73%, which is by the suggested alternative materials instead of existing ones. By application of FCM, which is a multi-criteria decision making (MCDM) technique, it has been observed that the polished Kota-stone flooring, stone-floor tile cladding, toughened fibre-glass ceiling and insulated fibre-glass door appear to be the most feasible sustainable material for flooring, wall cladding, ceiling, openings and fenestrations for the design of the metro rail station box in Ahmedabad, India. This study contributes significant knowledge in the field by highlighting the application of BIM as a tool for sustainable development and recommends a few alternate building materials and sustainable designs which would result in the reduction of energy usage for the metro-rail-station and other building structures leading to a sustainable future.

Application of integrated fuzzy FCM-BIM-IoT for sustainable material selection and energy management of metro rail station box project in western India

Fuzzy Factor Comparison Method is a paired comparison-based Multi-Criteria Decision-Making method which can be effectively applied for selection of the best feasible alternative among a set of available alternatives. This paper aims at developing a methodology by application of fuzzy Factor Comparison Method for selection of most feasible, sustainable material for the design of floor, ceiling, walls, cladding, openings and fenestrations for an infrastructure transportation facility like metro rail station box of Ahmedabad, India. Results of fuzzy Factor Comparison Method reveal that polished Kota stone tiles, toughened fibreglass ceiling, Kota stone wall tiles and insulated fibreglass door appear to be the most feasible sustainable materials. Evaluation of the alternative building materials and design strategies was carried out through Building Information Modelling, and the observed results show 73% of average embodied energy savings achieved by the suggested alternative materials instead of the existing ones. Furthermore, this study also proposes a framework for real-time automated Building Information Modelling-enabled energy management system for the elevated metro rail station by the Internet of Things sensors. It has been observed that more than 25% of the operational cooling load can be reduced by the proposed integrated Building Information Modelling-Internet of Things framework. This novel approach plays a key role in the sustainable future of infrastructure projects.

Precast Bamboo Reinforced Furniture Elements using Self Compacting Concrete

Public furniture in India are designed based on ergonomics standards derived from the international standards proving a significant hurdle in comfort for the users. We propose to tackle this by conducting ergonomic studies of true users. This study aims to check the viability of using an eco-friendly composite as street furniture, i.e., Park Bench. Additionally, owing to the increasing negative impact steel manufacturing has on the environment, the furniture is designed using a Bamboo-SCC composite. The objective of the study is to use bamboo as reinforcement in SCC to make furniture. The furniture is made using self-compacting concrete to ensure greater stability of the bamboo reinforcement and further to increase the durability of the benches. The final product is analysed based on deflection tests, cost-benefit analysis, and embodied energy savings. It was concluded that in areas where bamboo is readily available, this project can be implemented as a more energy-efficient and low-cost option.

Optimizing the architectural layouts and technical specifications of curtain walls to minimize use of aluminium

During the recent decades it has become common to enclose large buildings with lightweight, weathertight walls that hang, like curtains, from the floor edges. The frames of these curtain walls are, usually, extruded aluminium – a material whose production is highly energy-intensive. Although means of enhancing the thermal performance of building envelopes have been scrutinized, comparatively little attention has been given to the cost and embodied energy savings that can be achieved through efficient structural design. No guidelines for efficient use of aluminium in a curtain wall have been published, and architects therefore have not known the impact that their decisions have upon the facade's material content.In this study more than 1000 unique curtain wall systems have been optimized numerically, each one to a different set of design criteria, and the results show the extent to which aluminium content is influenced by floor height, locations of supports, number of horizontal members per panel, width of the extrusions, spacing between mullions, design wind pressure, and the minimum allowable thickness of aluminium. The conditions in which the amount of metal required to construct a window wall (glazing spanning between two floors) might be less than that required for a curtain wall (an uninterrupted, multi-floor shroud), also have been explored. The results show that substantial metal savings – reductions of 40% or more – can be realized by making modest changes to the layout geometries and specifications that are in common use. The value of the corresponding construction cost reductions is significant: in the worldwide construction market, the potential savings are in billions of dollars per year.The practical steps that an architect and specifier should take in order to reduce metal content in a curtain wall are set out in a list. These savings are separate from, and in addition to, any that might be attained by optimizing the cross-sectional shapes of extrusion profiles.Unlike improvements in a facade's thermal performance, which usually require capital investment in insulating materials for returns that accrue over decades, material-efficient design methods are free to apply, and the benefits can be enjoyed immediately.

Concrete structures using fabric formwork

Using fabric formwork, it is possible to cast architecturally interesting, optimised structures that use up to 40% less concrete than an equivalent strength prismatic section, thereby offering the potential for significant embodied energy savings in new concrete structures. This paper reports on the philosophy of and background to fabric formwork before techniques for the design, optimisation and shape prediction of fabric formed concrete beams are presented. The practicality of construction with non-orthogonal elements is discussed before the results of new structural test data, undertaken at the University of Bath on 4m span elements formed in reusable fabric moulds, are presented. Potential areas of future development for fabric formwork, including the use of woven advanced composite fabrics as permanent participating formwork and the feasibility of uniform strength prestressed beams, are then discussed.

Urban form and life-cycle energy consumption: Case studies at the city scale

By combining daily (operations) and embodied energy demands, this work estimates life-cycle energy demands for residents and workers in different city settings. Using life-cycle analyses (LCAs) of different neighborhood types in Austin, Texas, this analysis fabricates five different city types, reflecting actual accessibility and resident and employment density profiles. Five residential and three commercial neighborhood types are distributed across 16-kilometer (10-mile) radius regions, with demographics held constant, for comparability. As expected, per-capita daily energy demands decrease with increased resident and employment density. Interestingly, embodied energy savings via increases in density are substantial. Though embodied energy makes up only 10-20 percent of total life-cycle energy, per-capita savings via density suggest it should be included in planning analyses. Overall, average life-cycle per-capita energy use ranges from 140 gigajoule (GJ)/ year/capita in the least dense Orlando-style setting to around 90 GJ/ year/capita in the maximum-density scenario, corresponding to a 35 percent reduction in per-capita energy demand. Energy reductions for Phoenix, Austin, and Seattle settings (relative to an Orlando-based de- sign) are 18, 22, and 24 percent per-capita, respectively. Results provide a rare view of how total annual energy demands in both residential and commercial sectors are affected by density.

Identifying the potential for resource and embodied energy savings within the UK building sector

The EU building sector is widely acknowledged as a primary source of anthropogenic emissions, contributing directly to climate change. Recent studies estimate the sector to account for approximately 40% of primary energy use and 50% of extracted materials within the European Union. The Energy Performance of Buildings Directive 2010/31/EU requires efficiency improvements to be implemented in all new EU buildings, with a requirement that from 2020 all new buildings constructed should be “nearly energy zero”. From this stance the embodied energy of a building, when taking a full life-cycle perspective, is gaining importance and will become a more dominant issue to tackle when striving for sector-wide reduction in the coming years. This research took the UK as a case study and investigated where reduction measures are most suited to reduce material and energy consumption. The study proposes four reduction measures strategically focusing on hotspots of excessive consumption. The findings demonstrate that significant reductions can be achieved for the UK building sector's annual material and embodied energy consumption in the short to midterm, with projections estimating resource and embodied energy savings respectively of 4.7% and 6.4% by 2020 and 9.3% and 28.6% by 2030.

Embodied Energy Assessment and Comparisons for a Residential Building Using Conventional and Alternative Materials in Indian Context

Building sector is responsible for 40 % of the primary energy use and 24 % of carbon dioxide emissions in India. The main source of green house gas emissions from buildings is due to energy consumption. This paper aims to assess the embodied energy index and environmental impact of a two storied residential building. The study proposes various alternative materials which can be used in day to day construction in order to mitigate the environmental impact and climate change due to construction activity in India. Two types of construction techniques have been considered for the study, namely load bearing and reinforced concrete framed construction. Embodied energy and carbon dioxide emissions of walling and roofing components using conventional and alternative materials has also been analyzed and compared. The comparison is done based on two parameters namely, embodied energy/m2 and CO2 emissions per unit of floor area. The study shows that bricks, cement and steel are the three major contributors to the energy cost of constructing a building by conventional methods. A conventional two storied load bearing structure is 22 % more energy efficient when compared to a reinforced concrete structure. It has also been observed from the study that use of alternative material in the building envelope gives embodied energy savings between 50 and 60 % for a two storey load bearing structure and 30–42 % for a two storey reinforced concrete structure. Hence a load bearing construction is certainly a better alternative to RC framed construction for up to two storied structures in terms of embodied energy and environmental impacts.

Comparing the Environmental Impact of Stabilisers for Unfired Earth Construction

Buildings account for approximately one third of the total worldwide energy emissions, of which approximately a quarter can be attributed to the embodied energy of the building. Current UK legislation for low-energy homes is only concerned with operational energy. Embodied energy, and carbon, is not currently considered but over the design life of an average building is expected to make a significant contribution to the total whole life energy used. Earthen building materials contribute to reduce energy consumption in use through their passive regulation of temperature and humidity. In addition, there can also be significant embodied energy savings compared to other materials. Traditional methods of earthen construction, using locally sourced materials and manual labour require minimal energy for the transport and construction. A greater uptake of earth construction is likely to come from modern innovations such as industrialised manufacture. Extruded fired brick manufacturing processes has the potential to produce a high quality, low cost and low energy product suitable for the mainstream construction sector in both developed and developing nations. By not firing the extruded clay bricks, an embodied energy saving of 86% can be achieved, compared to fired clay, and 25% compared to concrete blocks. However, there are limitations to the structural use of unstabilised earth bricks due to the loss of strength under high moisture content conditions. The use of traditional and novel stabilisation methods can be adopted to address the concerns over strength and durability. Cement and lime are widely used in some countries, but both significantly increase material embodied energy and carbon and can inhibit passive humidity regulation. The paper presents results from a study of the embodied energy of various stabilisers used for unfired clay materials. The Global Warming Potential (GWP) is a measure of the equivalent carbon dioxide that allows for the relative weightings of damaging greenhouse gasses. Both the embodied energy and the GWP figures of various stabilisers are compared and discussed. The conclusion of the work is that there is a maximum quantity of stabiliser than should be used. Typically the quantities of stabiliser are quoted as the amount that gives the maximum strength, but this should take account of not only strength but the environmental impact of achieving the improvement.

Energy, economic and environmental analysis of metal oxides nanofluid for flat-plate solar collector

For a solar thermal system, increasing the heat transfer area can increase the output temperature of the system. However, this approach leads to a bigger and bulkier collector. It will then increase the cost and energy needed to manufacture the solar collector. This study is carried out to estimate the potential to design a smaller solar collector that can produce the same desired output temperature. This is possible by using nanofluid as working fluid. By using numerical methods and data from literatures, efficiency, size reduction, cost and embodied energy savings are calculated for various nanofluids. From the study, it was estimated that 10,239kg, 8625kg, 8857kg and 8618kg total weight for 1000 units of solar collectors can be saved for CuO, SiO2, TiO2 and Al2O3 nanofluid respectively. The average value of 220MJ embodied energy can be saved for each collector, 2.4years payback period can be achieved and around 170kg less CO2 emissions in average can be offset for the nanofluid based solar collector compared to a conventional solar collector. Finally, the environmental damage cost can also be reduced with the nanofluid based solar collector.

Appraisal of Vernacular Building Materials and Alternative Technoligies for Roofing and Terracing Options of Embodied Energy in Buildings

Nearly two million residential building are built annually in India apart from the offices, commercial and industrial buildings with demand and supply which is increasing year by year. It is essential to conserve the conventional energy by developing energy efficient buildings. Environmental quality and conservation of fossil fuels may become important in the context of limiting of GHGs emission and also reducing cost of materials. The most important stages from point of view of energy intensity: (a) Raw material acquisition; (b) Preparation & Manufacturing;(c) Transportation But this paper broadly considered to analyze the first two parts as the third part of transportation energy vary from location to location, however it has been emphasized in the literature that 1MJ/ tonne /km (diesel) for transporting materials can be integrated for location specific analysis. Besides, Energy estimates given in the literature for various materials such as the Cement 5.85MJ/kg, lime 5.62MJ/kg, LP 2.33MJ/kg (lime 30%, Pozzolana 60% and 10%calcined gypsum), steel 42MJ/kg, Al 236.8MJ/kg, Glass 25.8Mj/kg, Burnt clay brick 4.25MJ, Hollow block 12.3-15MJ, etc have been considered for energy appraisal. It is focused on some issues pertaining to Embodied Energy savings by identifying a few appropriate options for important building components and a comparison of energy in different types of roof and terracing has been made. Energy in different options of alternative systems have been discussed and compared with the energy consumed in conventional specifications to appreciate the consumption of energy in various materials for selection of appropriate materials with reference to energy savings and sustainable development.

Life cycle greenhouse gas emissions and energy analysis of prefabricated reusable building modules

Prefabrication is one strategy considered to provide improved environmental performance for building construction. However, there is an absence of detailed scientific research or case studies dealing with the potential environmental benefits of prefabrication, particularly the embodied energy savings resulting from waste reduction and the improved efficiency of material usage. This paper aims to quantify the embodied energy of modular prefabricated steel and timber multi-residential buildings in order to determine whether this form of construction provides improved environmental performance over conventional concrete construction methods. Furthermore this paper assesses the potential benefits of reusability of materials, reducing the space required for landfill and need for additional resource requirements.An eight-storey, 3943m2 multi-residential building was investigated. It was found that a steel-structured prefabricated system resulted in reduced material consumption of up to 78% by mass compared to conventional concrete construction. However, the prefabricated steel building resulted in a significant increase (∼50%) in embodied energy compared to the concrete building. It was shown that there was significant potential for the reuse of materials in the prefabricated steel building, representing up to an 81% saving in embodied energy and 51% materials saving by mass. This form of construction has the potential to contribute significantly towards improved environmental sustainability in the construction industry.

Assessing embodied energy of building structural elements

Although operational energy is currently the focal point of sustainability in building regulations, embodied energy and carbon dioxide emissions will become more significant as operational energy consumption is reduced. In the near future, embodied energy could account for a significant proportion of a building's carbon footprint over its lifetime, bearing in mind that the construction of energy-efficient buildings is carbon and energy intensive. Unlike operational energy, embodied energy savings have an immediate significant effect on carbon footprint and are independent of human behaviour. However, there is a lack of consensus within the construction industry on how to assess embodied energy and carbon dioxide and where to draw system boundaries, which has impeded advancement on the issue. This paper analyses the life-cycle embodied energy and carbon dioxide emissions of a building's structural elements, and examines which stages within a building's life are the most significant and offer the most opportunities for a reduction of embodied energy and carbon dioxide. The embodied energy and associated carbon dioxide at the product and construction, maintenance and end-of-life stages of a structure are examined, as well as the potential for energy recovery and carbon dioxide offsetting. A simple single-storey structure is used as a case study to perform comparative analyses between two structural design alternatives: glue-laminated timber panels and steel frame with infill concrete blockwork.

Modeling the Thermal Effects of Artificial Turf on the Urban Environment

Abstract The effects of artificial turf (AT) on the urban canopy layer energy balance, air and surface temperatures, and building cooling loads are compared to those of other common ground surface materials (asphalt, concrete, and grass) through heat transfer modeling of radiation, convection, and conduction. The authors apply the Temperatures of Urban Facets in 3D (TUF3D) model—modified to account for latent heat fluxes—to a clear summer day at a latitude of 33° over a typical coastal suburban area in Southern California. The low albedo of artificial turf relative to the other materials under investigation results in a reduction in shortwave radiation incident on nearby building walls and an approximately equal increase in longwave radiation. Consequently, building walls remain at a relatively cool temperature that is similar to those that are adjacent to irrigated grass surfaces. Using a simple offline convection model, replacing grass ground cover with artificial turf was found to add 2.3 kW h m−2 day−1 of heat to the atmosphere, which could result in urban air temperature increases of up to 4°C. Local effects of AT on building design cooling loads were estimated. The increased canopy air temperatures with AT increase heat conduction through the building envelope and ventilation in comparison with a building near irrigated grass. However, in this temperate climate these loads are small relative to the reduction in radiative cooling load through windows. Consequently, overall building design cooling loads near AT decrease by 15%–20%. In addition, the irrigation water conservation with AT causes an embodied energy savings of 10 W h m−2 day−1. Locally, this study points to a win–win situation for AT use for urban landscaping as it results in water and energy conservation.

An analysis of factors influencing waste minimisation and use of recycled materials for the construction of residential buildings

Residential building construction activities, whether it is new build, repair or maintenance, consumes a large amount of natural resources. This has a negative impact on the environment in the form depleting natural resources, increasing waste production and pollution. Previous research has identified the benefits of preventing or reducing material waste, mainly in terms of the limited available space for waste disposal, and escalating costs associated with landfills, waste management and disposal and their impact on a building company's profitability. There has however been little development internationally of innovative waste management strategies aimed at reducing the resource requirement of the construction process. The authors contend that embodied energy is a useful indicator of resource value. Using data provided by a regional high‐volume residential builder in the State of Victoria, Australia, this paper identifies the various types of waste that are generated from the construction of a typical standard house. It was found that in this particular case, wasted amounts of materials were less than those found previously by others for cases in capital cities (5‐10 per cent), suggesting that waste minimisation strategies are successfully being implemented. Cost and embodied energy savings from using materials with recycled content are potentially more beneficial in terms of embodied energy and resource depletion than waste minimisation strategies.

96/04231 Assessing the embodied energy savings from recycling and alternate materials in buildings

96/04231 Assessing the embodied energy savings from recycling and alternate materials in buildings