Life-cycle energy analysis of buildings: a case study

Energy use is a widely used measure of the environmental impact of buildings. Recent studies have highlighted the importance of both the operational and embodied energy attributable to buildings over their lifetime. The method of assessing lifetime building energy is known as life-cycle energy analysis. With Kyoto target obligations necessitating the quantification of greenhouse gas emissions at the national level, it seems increasingly probable that analyses of this kind will increase in use. If conducted in primary energy terms, such analyses directly reflect greenhouse gas emissions, except for a few processes which involve significant non-energy related emissions such as cement manufacture. A Life-Cycle Assessment would include these issues, as well as other environmental parameters, though probably with a corresponding decrease in system boundary completeness. This paper briefly explains some of the theoretical issues associated with life-cycle energy analysis and then uses an Australian based case study to demonstrate its use in evaluating alternative design strategies for an energy efficient residential building. For example, it was found that the addition of higher levels of insulation in Australia paid back its initial embodied energy in life-cycle energy terms in around 12 years. However, the saving represented less than 6% of the total embodied energy and operational energy of the building over a 100-year life cycle. This indicates that there may be other strategies worth pursuing before additional insulation. Energy efficiency and other environmental strategies should be prioritized on a life-cycle basis. La consommation d'energie est un parametre tres utilise lorsque l'on veut mesurer l'impact des batiments sur l'environnement. Des etudes conduites recemment ont mis en lumiere l'importance de l'energie operationnelle et celle de l'energie intrinseque degagees par les batiments pendant leur duree de vie. L'analyse energetique des batiments pendant leur cycle de vie est une methode d'evaluation de l'energie d'un batiment pendant sa duree de vie. Pour respecter les objectifs de la Conference de Kyoto, il faut quantifier les emissions de gaz de serre au niveau national; il semble donc de plus en plus probable que la pratique de ces analyses va aller en augmentant. Si elles portent sur l'energie primaire, ces analyses rendront parfaitement compte des emissions de gaz a effets de serre, sauf pour quelques procedes industriels, comme la fabrication du ciment, ou les emissions de ces gaz ne sont pas liees a l'energie. Toute evaluation du cycle de vie doit tenir compte de ces questions mais aussi d'autres parametres environnementaux, mais avec, sans doute, une moindre nettete des limites des systemes. Le presente communication expose brievement quelques uns des problemes theoriques lies aux analyses energetiques sur le cycle de vie et s'appuie sur une etude de cas australienne pour demontrer son utilite a evaluer d'autres strategies de conception de batiments a usage d'habitation a faible consommation d'energie. On a constate, par exemple, qu'en Australie le fait d'ajouter des niveaux d'isolation remboursait en 12 ans environ l'energie intrinseque initiale en terme d'energie sur le cycle de vie. Toutefois, les economies representaient moins de 6% de l'energie intrinseque totale et de l'energie operationnelle du batiment sur un cycle de vie de 100 ans. Cela veut dire qu'il serait peut etre interessant d'envisager d'autres strategies avant d'augmenter l'isolation. On devrait donner priorite a l'efficacite energetique et a d'autres strategies environnementales sur la base du cycle de vie.     

Life-cycle energy analysis of buildings: a case study

Energy use is a widely used measure of the environmental impact of buildings. Recent studies have highlighted the importance of both the operational and embodied energy attributable to buildings over their lifetime. The method of assessing lifetime building energy is known as life-cycle energy analysis. With Kyoto target obligations necessitating the quantification of greenhouse gas emissions at the national level, it seems increasingly probable that analyses of this kind will increase in use. If conducted in primary energy terms, such analyses directly reflect greenhouse gas emissions, except for a few processes which involve significant non-energy related emissions such as cement manufacture. A Life-Cycle Assessment would include these issues, as well as other environmental parameters, though probably with a corresponding decrease in system boundary completeness. This paper briefly explains some of the theoretical issues associated with life-cycle energy analysis and then uses an Australian based case study to demonstrate its use in evaluating alternative design strategies for an energy efficient residential building. For example, it was found that the addition of higher levels of insulation in Australia paid back its initial embodied energy in life-cycle energy terms in around 12 years. However, the saving represented less than 6% of the total embodied energy and operational energy of the building over a 100-year life cycle. This indicates that there may be other strategies worth pursuing before additional insulation. Energy efficiency and other environmental strategies should be prioritized on a life-cycle basis.

La consommation d'énergie est un paramètre très utilisé lorsque l'on veut mesurer l'impact des bâtiments sur l'environnement. Des études conduites récemment ont mis en lumière l'importance de l'énergie opérationnelle et celle de l'énergie intrinsèque dégagées par les bâtiments pendant leur durée de vie. L'analyse énergétique des bâtiments pendant leur cycle de vie est une méthode d'évaluation de l'énergie d'un bâtiment pendant sa durée de vie. Pour respecter les objectifs de la Conférence de Kyoto, il faut quantifier les émissions de gaz de serre au niveau national; il semble donc de plus en plus probable que la pratique de ces analyses va aller en augmentant. Si elles portent sur l'énergie primaire, ces analyses rendront parfaitement compte des émissions de gaz à effets de serre, sauf pour quelques procédés industriels, comme la fabrication du ciment, où les émissions de ces gaz ne sont pas liées à l'énergie. Toute évaluation du cycle de vie doit tenir compte de ces questions mais aussi d'autres paramètres environnementaux, mais avec, sans doute, une moindre netteté des limites des systèmes. Le présente communication expose brièvement quelques uns des problèmes théoriques liés aux analyses ènergétiques sur le cycle de vie et s'appuie sur une étude de cas australienne pour démontrer son utilitè à évaluer d'autres stratégies de conception de bâtiments à usage d'habitation à faible consommation d'énergie. On a constaté, par exemple, qu'en Australie le fait d'ajouter des niveaux d'isolation remboursait en 12 ans environ l'énergie intrinsèque initiale en terme d'énergie sur le cycle de vie. Toutefois, les economies répresentaient moins de 6% de l'énergie intrinsèque totale et de l'energie opérationnelle du bâtiment sur un cycle de vie de 100 ans. Cela veut dire qu'il serait peut etre intéressant d'envisager d'autres stratégies avant d'augmenter l'isolation. On devrait donner priorité à l'efficacité énergétique et à d'autres stratégies environnementales sur la base du cycle de vie.     

Movers and stayers: The resident's contribution to variation across houses in energy consumption for space heating

A general method is proposed that identifies the contribution of resident-dependent effects to the observed variability of energy consumption in similar houses. The method presumes that in addition to records of energy consumption over time, one has access to information about the date of change of occupants. For Twin Rivers data, the role of resident-dependent effects is seen to dominate the role of effects that depend on structural variations over which the resident has no effective control.     

Long-term impact of water desalination plants on the energy and carbon dioxide balance of Victoria,Australia: a case study from Wonthaggi

In 2007, the state government of Victoria, Australia, announced plans to build a large desalination plant with a capacity of 150 million m³ per year of desalinated water. Currently, the only feasible source for significant expansion of the greenhouse-gas neutral (GGN) energy generation in the state is wind power. A criterion for GGN of a desalination plant has been formulated. In a case of no greenhouse gas contribution from the desalination plant, the criterion is satisfied if the annual growth of the electrical energy generated by GGN sources is around 6–9% for the period 2010–2070. Higher annual growth of 18% for the period 2008–2015, 8% annually for the period 2015–2035 and 6% annual growth thereafter are required if the desalination plant is contributing to the greenhouse-gas balance of the state.     

Opportunities for tidal range projects beyond energy generation: Using Mersey barrage as a case study

Currently there is renewed interest in harnessing the vast tidal resource to combat the twin challenges of climate change and energy security. However, within the UK no tidal barrage proposals have passed the development stage, this is due to a combination of high cost and environmental concerns. This paper demonstrates how a framework, such as the North West Hydro Resource Model can be applied to tidal barrages, with the Mersey barrage as a case study. The model materialised in order to provide developers with a tool to successfully identify the capacity of hydropower schemes in a specific location. A key feature of the resource model is the understanding that there is no single barrier to the utilisation of small hydropower but several obstacles, which together impede development. Thus, this paper contributes in part to a fully holistic treatment of tidal barrages, recognising that apart from energy generation, other environmental, societal and economic opportunities arise and must be fully investigated for robust decision-making. This study demonstrates how considering the societal needs of the people and the necessity for compensatory habitats, for example, an organic architectural design has developed, which aims to enhance rather than detract from the Mersey.     

Impacts of energy legislation on organizational motivation: a case study

ABSTRACT

In an attempt to reduce operational energy use in non-domestic buildings and mitigate climate change, the UK government has introduced Energy Savings Opportunity Scheme (ESOS) legislation to motivate large organizations to implement energy-efficiency (EE) measures. However, evidence suggests that an organization’s behaviour with regard to EE measures does not follow rational cost minimization, demonstrating potential ESOS weakness. A case study is presented that assesses whether ESOS can lead to EE measures deployment despite different overarching agendas. A generic qualitative approach is used to assess the change within the organization; auto-ethnomethodology was used to assess the change within its facility management (FM). The results demonstrate that the energy audit delivered through an agenda of cost minimization was weak in creating organizational behaviour change. However, the ESOS audit along with the research process led to a mindset change of the FM, resetting an overarching agenda from cost minimization to co-evolution between a building and its occupants, further empowering the FM to facilitate behavioural change within the whole organization. These findings suggest that the success of EE policies can increase if policies shift from understanding end-users as passive to proactive and capable of shaping better outcomes for themselves and their organizations.     

Cardboard as a construction material: a case study

A small cardboard building with a 25-year intended lifetime was developed as a live innovation project to explore and resolve the practical problems surrounding the design, fabrication and construction, costs, and use of an alternative building material. The primary aim to reduce environmental impacts was based on developing the potential of a recycled material as the main structural and cladding component that could be further recycled at the end of its working life. This case study of a small school building presents both the research and development undertaken by the project team and the practical implications of realizing this as a building for a client.     

Cardboard as a construction material: a case study

A small cardboard building with a 25-year intended lifetime was developed as a live innovation project to explore and resolve the practical problems surrounding the design, fabrication and construction, costs, and use of an alternative building material. The primary aim to reduce environmental impacts was based on developing the potential of a recycled material as the main structural and cladding component that could be further recycled at the end of its working life. This case study of a small school building presents both the research and development undertaken by the project team and the practical implications of realizing this as a building for a client.     

Measuring the rebound effect: A case study of residential photovoltaic systems in San Diego

This study examines the effect of solar photovoltaic system installation on the electricity consumption in residential households across various geographic regions in San Diego. Using meter-level data, the electricity consumption for residential households is calculated before and after installation to assess whether there are any significant rebound effects in usage. Results reveal significant variations in the change in electricity usage depending on geographical location. The findings are relevant to regional resource planning and climate response, as the failure to account for the rebound effect may result in significant overestimation of the energy and emissions benefits of distributed renewable energy adoption.     

Modeling the dynamics of landscape structure in Asia’s emerging desakota regions: a case study in Shenzhen

The rapid urbanization taking place in Asia since 1970 has exhibited a process different from that of the developed countries in the West. This process has contributed to the emergence of a new landscape in Asia — widely known as the desakota (a combination of two Indonesian words: “desa” for village, “kota” for town) regions described in the McGee–Ginsburg model. These desakota regions are characterized by an intense mix of agricultural and non-agricultural activities that often stretch along corridors between large city cores. Although, the McGee–Ginsburg model captures the socio-demographic dimensions of the rapid urbanization process, little is known about the dynamics of landscape structures in the emerging desakota regions in Asia. By linking remote sensing, landscape characterization indices, and cellular automata modeling with geographic information systems (GIS), this paper develops a GIS-based spatial analysis and modeling approach to study the landscape dynamics of the desakota regions in southeast China. We tested our method using data between 1992 and 1996 for the city of Longhua in the Shenzhen Special Economic Zone — one of the fastest growing areas in southeast China. The results not only confirm the effectiveness of GIS-based spatial analysis and modeling approach in studying the ecological impacts of human activities, but also reveal the salient features of landscape dynamics in the desakota regions. Drawing from the results of this research, we conclude that the pace of urbanization and the size of desakota regions must be controlled in order to create a sustainable future in developing countries.     

Energy consumption and the potential of energy savings in Hellenic office buildings used as bank branches—A case study

Energy performance of non-residential buildings and in particular of office buildings used as bank branches is very limited. This paper presents new data from 39 representative bank branches and results from a more in-depth analysis of information from energy audits in 11 typical bank branches throughout Greece. The data was used to derive practical energy benchmarks and assess various energy conservation measures. Accordingly, the average annual total energy consumption is 345 kWh/m². The breakdown of the different end-uses reveals that HVAC averages 48% of the final energy consumption, lighting averages 35% and other office and electronic equipment average 17%. The most effective energy conservation measures reach annual energy savings of 56 kWh/m² by regulating the indoor set point temperature, while the use of HF electronic ballasts and CFL lamps may save about 22 kWh/m² and 29 kWh/m² with and without the use of the external marquee sign, respectively.     

The global GIS: a case study

Geographic information systems (GIS) play a crucial role in the management of the environment and allocation of resources in many application domains. We discuss appropriate technologies and their requirements including the GIS technology issues such as data acquisition, database technology and interoperability tools as well as the availability of suitable models. In this paper, the project I-VOIR is discussed which is a prototype for GIS inquiries via the Internet for inland shipping traffic. Our conclusions are based on the evaluation of this project.     

Habitat evaluation using GIS: A case study applied to the San Joaquin Kit Fox

Concern over the fate of plant and animal species throughout the world has accelerated over recent decades. Habitat loss is considered the main culprit in reducing many species’ abundance and range, leading to numerous efforts to plan and manage habitat preservation. Our work uses Geographic Information Systems (GIS) data and modeling to define a spatially explicit analysis of habitat value, using the San Joaquin Kit Fox (Vulpes macrotis mutica) of California (USA) as an example. Over the last 30 years, many field studies and surveys have enhanced our knowledge of the life history, behavior, and needs of the kit fox, which has been proposed as an umbrella or indicator species for grassland habitat in the San Joaquin Valley of California. There has yet been no attempt to convert much of this field knowledge into a model of spatial habitat value useful for planning purposes. This is a significant omission given the importance and visibility of the imperiled kit fox and increasing trends toward spatially explicit modeling and planning. In this paper we apply data from northern California to derive a small-cell GIS raster of habitat value for the kit fox that incorporates both intrinsic habitat quality and neighborhood context, as well the effects of barriers such as roads. Such a product is a useful basis for assessing the presence and amounts of good (and poor) quality habitat and for eventually constructing GIS representations of viable animal territories that could be included in future reserves.     

Architectural construction documents on the web: VRML as a case study

The Virtual Reality Modeling Language (VRML) and the World Wide Web (WWW) offer new opportunities to communicate an architect’s design intent throughout the design process. We have investigated the use of VRML in the production and communication of construction documents, the final phase of architectural building design. A prototype, experimental Web site was set up and used to disseminate design data as VRML models and HTML text to the design client, contractor, and fabricators.In this paper, we discuss the way our construction documents were developed in VRML, the issues we faced implementing it, and critical feedback from the users of the Web space/site. We analyze the usefulness of VRML as a communication tool for the design and construction industries. Finally, we discuss technical, social, and legal issues the AEC industry faces as it shifts to embrace widespread use of a “paperless” Web-based communications infrastructure for design documentation.Les documents de construction en architecture: le VRML, étude d'un cas spécifiqueLe “Virtual reality Modeling Language” (VRML) et le “World Wide Web” offrent de nouvelles possibilités de communiquer les intentions de l’architecte au cours du processus de la conception. Nous avons examiné l’utilisation de VRML lors de la production et la communication de dessins de construction, la dernière phase de la conception architecturale. Un site Web prototype expérimental a été établi et utilisé pour disséminer des textes et des modèles VRML du design aux clients, au contracteur, et aux fabricants.Dans ce papier nous expliquons la façon dont nos documents de construction ont été développés en VRML, ainsi que les obstacles auxquels nous devions faire face lors de la mise en pratique, et les critiques des utilisateurs du site Web. Nous examinons l’utilité du VRML en tant qu’outil de communication pour les industries du design et de la construction. Enfin, nous discutons les conséquences sociales et légales pour l’industrie AEC lorsqu’elle se met à adopter l’utilisation universelle d’une infrastructure “sans papier” de communication, basée sur le Web pour les documents du design.     

浅谈建筑与城市的接续——以槙文彦设计的“山边露台”综合体为例

本文以槙文彦设计的"山边露台"综合体为例,通过现场调查与分析,将该建筑综合体与周边城区良好接续的关节点,通过"出入口""透明性""新旧关系"三个方面进行了梳理、分析与解读。     

居住建筑节能65%研究——以宁波为例

以宁波为例,使用DeST-h建立了一幢宁波地区节能50%的典型居住建筑模型,并将其定义为基准住宅.分析了基准住宅的围护结构能耗比例及节能潜力,并研究了宁波地区居住建筑节能65%的实现途径.结果表明,在节能50%基础上,再节能30%,可通过围护结构保温隔热性能的改善和供暖空调能效比的提高来实现,两者所占的节能份额约各一半.     

The influence of the IR reflection of painted facades on the energy balance of a building

The investigation on the effect of painted facades with spectrally selective properties on the energy balance of a building is made by comparing real measured data from an outdoor test of facade samples with data calculated using the ESP-r simulation program.The following factors were investigated: influence of solar radiation, calculated with a solar model, the absorption of direct solar radiation as a function of the angle of incidence, IR radiation exchange and the influence of heat loss caused by convection.During this investigation, it was determined that the influence of solar radiation and especially the heat loss caused by convection are the most dominant influences on the examined energy balance of a building.After adapting the simulation program in order to simulate the data correctly, the influence of selective facades is investigated using an office model as an example. In the case of the location of Freiburg, Germany, two different types of outer walls are investigated and described in this publication: A well-insulated wall with a U-value of 0.42 W/(m² K) and a poorly insulated wall with 1.95 W/(m² K).The savings in the heating demand are higher in the case of poorly insulated walls than in well-insulated walls. In contrast to this effect, the cooling demand increases nearly in the same way for both types of walls. The tendency for condensation is also weakened, as is documented in [4].     

Can weathering improve the toughness of a fractured rock? A case study using the San Giacomo granite

The physical–mechanical behaviour of the weathered San Giacomo granite, Sardinia, has been investigated using a combination of physical–mechanical tests and microstructural analysis. Fieldwork and microscopy suggest a pervasive microfracture system developed on a pre-existing magmatic quartz anisotropy. Alteration indices, chemical analyses and mineralogy indicate that the yellow staining is produced by the circulation of oxygen-rich rainwater through microfractures in the rock, resulting in the oxidation of biotites. Apart from the obvious modification of the original grey colouring, the precipitation of Fe-oxides and hydroxides has welded fractures together, leading to the partial recovery of the physical–mechanical properties previously compromised due to microfracturing.     

Using indicators to profile energy consumption and to inform energy policy in a university—A case study in Ireland

The services sector has the least amount of energy end use data available, which poses significant challenges to companies within the sector attempting to benchmark their energy performance and inform energy management decisions. This paper explores through a case study analysis the use of simple performance indicators and how additional data and new metrics can greatly enhance the understanding of energy trends and in particular the assessment of building energy performance. The country chosen for the analysis is Ireland, where the services sector has experienced high energy demand growth since 1990 (4.1% annually) compared with the EU-15 (1.5% annually). Despite this growth, the available energy data is poor, in particular for the public service sub-sectors. The case study chosen is an institution within the education sub-sector, University College Cork. The paper presents some simple energy performance indicators that have been used to date to inform energy policy. The paper then introduces new approaches and tools for assessing energy performance in buildings and how these may be utilised to improve the energy policy decision making and energy management. It discusses how these approaches are been implemented for buildings with separate functions, presents some initial results and discusses future planned work.