A life-cycle energy analysis of building materials in the Negev desert

Environmental quality has become increasingly affected by the built environment—as ultimately, buildings are responsible for the bulk of energy consumption and resultant atmospheric emissions in many countries. In recognizing this trend, research into building energy-efficiency has focused mainly on the energy required for a building's ongoing use, while the energy “embodied” in its production is often overlooked. Such an approach has led in recent years to strategies which improve a building's thermal performance, but which rely on high embodied-energy (EE) materials and products. Although assessment methods and databases have developed in recent years, the actual EE intensity for a given material may be highly dependent on local technologies and transportation distances. The objective of this study is to identify building materials which may optimize a building's energy requirements over its entire life cycle, by analyzing both embodied and operational energy consumption in a climatically responsive building in the Negev desert region of southern Israel—comparing its actual material composition with a number of possible alternatives. It was found that the embodied energy of the building accounts for some 60% of the overall life-cycle energy consumption, which could be reduced significantly by using “alternative” wall infill materials. The cumulative energy saved over a 50-year life cycle by this material substitution is on the order of 20%. While the studied wall systems (mass, insulation and finish materials) represent a significant portion of the initial EE of the building, the concrete structure (columns, beams, floor and ceiling slabs) on average constitutes about 50% of the building's pre-use phase energy.     

Inventory analysis of LCA on steel- and concrete-construction office buildings

A life-cycle inventory model for the office buildings is developed in this paper. The environmental effects of two different building structures, steel and concrete, are intercompared. The results show that the steel-framed building is superior to the concrete-framed building on the following two indexes, the life-cycle energy consumption and environmental emissions of building materials. It is found that the life-cycle energy consumption of building materials per area in the steel-framed building is 24.9% as that in the concrete-framed building, whereas, on use phase, the energy consumption and emissions of steel-framed building are both larger than those of concrete-framed building. As a result, lower energy consumption and environmental emissions are achieved by the concrete-framed building compared with the steel-framed building on the whole life cycle of building. The present study also provides a good method of assessing the performance of energy saving and environmental protection of different building structures based on a whole life cycle.     

Life-cycle cost optimal design of passive dissipative devices

The cost-effective performance of structures under natural hazards such as earthquakes and hurricanes has long been recognized to be an important topic in the design of civil engineering systems. A realistic comprehensive treatment of such a design requires proper integration of (i) methodologies for treating the uncertainties related to natural hazards and to the structural behavior over the entire life-cycle of the building, (ii) tools for evaluating the performance using socioeconomic criteria, as well as (iii) algorithms appropriate for stochastic analysis and optimization. A systematic probabilistic framework is presented here for detailed estimation and optimization of the life-cycle cost of engineering systems. This framework is a general one but the application of interest here is the design of passive dissipative devices for seismic risk mitigation. A comprehensive methodology is initially presented for earthquake loss estimation; this methodology uses the nonlinear time-history response of the structure under a given excitation to estimate the damage in a detailed, component level. A realistic probabilistic model is then presented for describing the ground motion time history for future earthquake excitations. In this setting, the life-cycle cost is uncertain and can be quantified by its expected value over the space of the uncertain parameters for the structural and excitation models. Because of the complexity of these models, calculation of this expected value is performed using stochastic simulation techniques. This approach, though, involves an unavoidable estimation error and significant computational cost, features which make efficient design optimization challenging. A highly efficient framework, consisting of two stages, is discussed for this stochastic optimization. An illustrative example is presented that shows the efficiency of the proposed methodology; it considers the seismic retrofitting of a four-story non-ductile reinforced-concrete building with viscous dampers.     

建筑材料的组合方式

在研究国内外相关设计实践及理论的基础上．本文重点从材料的知觉特性与空间关系的角度．总结出建筑材料的几种组合方式,并分析其对建筑表现的影响,为今后的设计实践,提供一定的借鉴和指导。     

整合介入——气候适应性建筑表皮的设计过程研究

气候适应性建筑表皮作为建筑物与空气、阳光、阴影和水的分界面。是协调内外环境的智能面层,已成为建筑表皮发展的新趋势。整合设计过程（IDP）也为可持续建筑设计（SBD）带来了新的契机。包括设计的创新以及设计决策的客观性。实际案例选择的建筑实践是将气候与地域文脉整合设计的典型案例,通过丰富的图例试图揭示气候适应性表皮构件复杂的层次关系。并体现出隐藏在建筑表皮外观下的建筑系统整合过程,凸显了整合设计的介入过程。     

超高层建筑结构生命周期多维度经济成本评估及优化方法

超高层建筑结构具有结构体系复杂、结构功能多样、生命周期长、投资量大、持有人固定不变等特点,其全生命周期成本费用包含初始费用、维护费用、灾害失效费用以及拆除费用等多项费用。为了实现超高层结构全生命周期经济利益最大化而采用的生命周期经济评估方法通过方案对比、构件对比、费用项目等多维度对超高层结构成本费用进行管理。使用该方法能够在项目初期就对结构项目进行全面的评估与优化,同时,一个超高层建筑的实例将被引用来说明其有效性与适用性。     

Air-handling energy efficiency and design practices

With good design practices and life-cycle cost optimization, the specific fan power for individual (SFPI) fans will be between 0.5 and 1 kW m⁻³⁻¹. Data from nearly 1000 audited fans in Sweden show that the average measured SFPI weighted by drawn motor power is 1.5 kW m⁻³ s⁻¹ and the situation appears to be similar in other countries. Contract forms used by Swedish builders and consultants' design practices are analyzed here to search for an explanation of the low performance of installed systems. Identified as two major barriers to efficient system design are the lack of performance specifications when procuring systems and the incentive structure in the building sector. As a consequence, duct design methods, rules of thumb, and vendor recommendations do not lead to system optimization. The broad minima in life-cycle costs over a range of air-handling unit sizes show that potential economic welfare losses from efficiency standards are likely to be smaller than the losses that result from today's design practices.     

A physical study of plumbing life cycle in apartment houses

We know that extending the life span of a building can reduce environmental impact, and also save money with the viewpoints of life-cycle cost. But due to the complex system construction of buildings, if we apply the concept of life-cycle cost to design, we must consider it in coordination with the life spans of subsystems in order to avoid unreasonable wastage and problems of utility function. Concerning corrosion of piping, past documents mostly direct investigation and analysis to the physical or chemical characteristics of materials. This paper focuses on the plumbing system of a building, by matching up the investigation of practical cases, we determined the life span of a plumbing system in a building and try to offer an assessment system for a life-cycle model. This could be of use in life-cycle architectural planning and design.     

建筑性能模拟软件在绿色建筑设计不同阶段的应用效果比较

建筑性能模拟软件在绿色建筑设计中承担了重要的作用,在本研究中主要探讨模拟软件使用的不同时期如何影响建筑性能表现和设计策略的选择。基于不同工作方式(不同阶段引入模拟软件)的两个真实设计案例,通过采访建筑师和调研设计过程的文本和资料,分析了两种不同工作方式的设计效果差异。模拟软件在早期介入的方案可以考虑更多与当地气候相适应的被动式的设计策略,而模拟软件在晚期介入的方案更多地考虑用主动技术的方式来实现建筑性能的指标。本研究建议将被动式设计策略引入到绿色建筑评估体系中,以鼓励设计团队在早期设计阶段就采用模拟软件指导设计的工作方式。     

零能耗建筑的整合设计与实践——以清华大学O-House太阳能实验住宅为例

针对建筑、技术和工程的整合设计是可持续建筑设计的一项重要议题。城市住宅面临人口密度高、建造方法传统、建筑物理性能缺陷、系统设备老化和资源紧缺等诸多问题,且这些问题在中国大中城市尤为显著,因此,整合可持续策略与住宅建筑设计成为一项挑战。本文意在建立一个基于中国住宅市场情况、在零能耗住宅设计到建造的过程中、整合可持续策略的技术框架。O-House是中国国际太阳能十项全能竞赛的参赛作品之一,是一个面向中国住宅市场的零能耗建筑。该实例证明了建筑的组成发展模式、建筑设计和材料、建筑与可再生资源策略利用的一体化、建筑与系统设备一体化、建筑与室内家具一体化等整合设计的策略和流程。文末列举了可持续住宅设计的利用范围领域,同时指出未来发展中可能存在的优势和局限。     

Life-cycle of structural systems: recent achievements and future directions

Structural systems are under deterioration due to ageing, mechanical stressors, and harsh environment, among other threats. Corrosion and fatigue can cause gradual structural deterioration. Moreover, natural and man-made hazards may lead to a sudden drop in the structural performance. Inspection and maintenance actions are performed to monitor the structural safety and maintain the performance over certain thresholds. However, these actions must be effectively planned throughout the life-cycle of a system to ensure the optimum budget allocation and maximum possible service life without adverse effects on the structural system safety. Life-cycle engineering provides rational means to optimise life-cycle aspects, starting from the initial design and construction to dismantling and replacing the system at the end of its service life. This paper presents a brief overview of the recent research achievements in the field of life-cycle engineering for civil and marine structural systems and indicates future directions in this research field. Several aspects of life-cycle engineering are presented, including the performance prediction under uncertainty and optimisation of life-cycle cost and intervention activities, as well as the role of structural health monitoring and non-destructive testing techniques in supporting the life-cycle management decisions. Risk, resilience, sustainability, and their integration into the life-cycle management are also discussed.     

建筑材料在建筑表皮中的生态运用

本文以建筑材料为切人点,着重阐述了建筑材料在建筑表皮中的生态运用策略。建筑材料的使用贯穿了建筑建造、维护以及改造等整个生命周期。材料会对建筑的外观、性能和建造成本造成影响。经过几十年的发展科研人员对材料的特性有了新的了解。材料有了全生命周期评价（LCA）,当材料选择时可以考虑在建造过程中的可持续问题。通过材料在建筑表皮中的分层组成方式的分析模拟,设备的控制以及空腔等系统和材料自身物理性能,来完成应对气候和建筑微气候的适应及其变化。     

BEPAS—a life cycle building environmental performance assessment model

This paper presents a building environmental performance analysis system—BEPAS, which was developed based on the life cycle assessment (LCA) framework. In BEPAS, environmental impacts were investigated in three main aspects of a building that were closely related to environmental performance—building facilities, building materials and location. In addition, a set of environmental databases were developed, covering the environmental performance profiles of these environmental aspects. The BEPAS can be used to assess the environmental performance of a new or existing building. This paper also discusses a case project in order to illustrate the assessment procedures and test the effectiveness of the system in application.     

Life cycle cost implications of energy efficiency measures in new residential buildings

The importance of the built environment from an environmental impact and energy use perspective is well established. High thermal efficiency of the constructed building envelope is a key strategy in the design and construction of buildings which limit use of active space conditioning systems. Australia's current housing stock is thermally poor and national energy performance standards are relatively weak when benchmarked against international best practice. A lack of data has impeded the policy debate and a significant gap in analysis remains a lack of empirical research into the life-cycle cost implications of increased building thermal efficiency, particularly for residential buildings. This paper applies an integrated thermal modeling, life cycle costing approach to an extensive sample of dominant house designs to investigate life cycle costs in a cool temperate climate, Melbourne Victoria. Empirical analysis provides new insights into lifetime costs and environmental savings for volume housing design options and identifies sensitive factors. Results suggest that the most cost-effective building design is always more energy efficient than the current energy code requirements, for the full time-horizon considered. Findings have significant policy implications, particularly in view of present debates which frequently present higher energy efficiency standards as prohibitive from a costs perspective.     

Bridge life-cycle performance and cost: analysis,prediction, optimisation and decision-making

The development of a generalised framework for assessing bridge life-cycle performance and cost, with emphasis on analysis, prediction, optimisation and decision-making under uncertainty, is briefly addressed. The central issue underlying the importance of the life-cycle approach to bridge engineering is the need for a rational basis for making informed decisions regarding design, construction, inspection, monitoring, maintenance, repair, rehabilitation, replacement and management of bridges under uncertainty which is carried out by using multi-objective optimisation procedures that balance conflicting criteria such as performance and cost. A number of significant developments are summarised, including time-variant reliability, risk, resilience, and sustainability of bridges, bridge transportation networks and interdependent infrastructure systems. Furthermore, the effects of climate change on the probabilistic life-cycle performance assessment of highway bridges are addressed. Moreover, integration of SHM and updating in bridge management and probabilistic life-cycle optimisation considering multi-attribute utility and risk attitudes are presented.     

高性能结构抗多次多种灾害全寿命性能分析与设计理论研究进展

为促进高性能结构抗多次多种灾害全寿命性能设计理论研究在我国的发展,详细介绍了该领域的国内外研究现状并建立了其基本研究框架。对高性能结构在全寿命周期内可能遭受的多种灾害单独作用和联合作用的发生概率模型的研究成果进行了阐述,以碳化腐蚀作用和风致疲劳作用为例,论述了在结构全寿命周期内由环境作用引起材料及构件退化的时变模型研究现状,为开展多次多种灾害作用下高性能结构的全寿命性能分析研究提供了方向,并系统介绍了多种灾害作用下结构易损性分析方法和考虑灾害损失成本的结构全寿命抗灾性能优化设计方法的研究进展。基于全寿命周期的结构抗多次多种灾害性能设计方法,能够合理地解决传统设计方法中未考虑多种灾害联合作用和结构性能退化问题,对于建筑结构设计领域的发展具有重要意义。     

基于建筑环境性能评估体系的住宅建筑设计策略探究

通过对国内外现行的具有代表性的建筑环境性能评估体系(LEED、GBTOOL、EcoHomes、CASBEE以及《绿色建筑评价标准》)的深入研究,该文试图从这些评估体系的指标系统中提取出能够为建筑师绿色建筑设计决策过程提供指导的设计策略。首先,从整体上分析研究目前国内外建筑环境性能评估体系的评价因素构成特征;其次,在此基础上将所举评估体系的评价因素指标进行分类,找出有关住宅建筑设计决策的评价因素指标;最后,将这些评价因素指标按特定的框架分类,以形成开放的设计策略体系。     

Sustainability assessment and rating of buildings: Developing the methodology SBTool–H

Although sustainable building is a multidimensional concept, attention to the issue often focuses solely on environmental indicators, ignoring the substantial importance of social, economic and cultural indicators. Building sustainability involves various relations between built, natural and social systems and therefore comprises a complex of different priorities that require consideration at each stage of a building’s life-cycle. To cope with this complexity and to support sustainability systematic, holistic and practical approaches to building design need to be developed. The main objective of a systematic methodology is to support the development of a building design that achieves the most appropriate balance between the different sustainability dimensions, and is, at the same time, practical, transparent and flexible enough to be easily adapted to different types of buildings and technology.     

Uncertainty-based life-cycle analysis of near-zero energy buildings for performance improvements

Near-zero energy buildings( nZEBs) are considered as an effective solution to mitigating CO_2 emissions and reducing the energy usage in the building sector. A proper sizing of the nZEB systems( e. g. HVAC systems,energy supply systems,energy storage systems, etc.) is essential for achieving the desired annual energy balance,thermal comfort,and grid independence. Two significant factors affecting the sizing of nZEB systems are the uncertainties confronted by the building usage condition and weather condition,and the degradation effects in nZEB system components. The former factor has been studied by many researchers; however,the impact of degradation is still neglected in most studies. Degradation is prevalent in energy components of nZEB and inevitably leads to the deterioration of nZEB life-cycle performance. As a result,neglecting the degradation effects may lead to a system design which can only achieve the desired performance at the beginning several years. This paper,therefore,proposes a life-cycle performance analysis( LCPA) method for investigating the impact of degradation on the longitudinal performance of the nZEBs. The method not only integrates the uncertainties in predicting building thermal load and weather condition,but also considers the degradation in the nZEB systems. Based on the proposed LCPA method,a two-stage method is proposed to improve the sizing of the nZEB systems.The study can improve the designers "understanding of the components"degradation impacts and the proposed method is effective in the life-cycle performance analysis and improvements of nZEBs. It is the first time that the impacts of degradation and uncertainties on nZEB LCP are analysed. Case studies showthat an nZEB might not fulfil its definition at all after some years due to component degradation,while the proposed two-stage design method can effectively alleviate this problem.     

Critical Building Design Factors for Indoor Air Quality and Climate: Current Status and Predicted Trends

In recent yean, some building design professionals have become more aware of the indoor air quality concerns of owners and occupants and as a result, they have made some important changes to improve indoor air quality and climate. These changes include improvements in site planning and design; overall building design; ventilation and climate control systems; and materials selection and specifications. In addition, changes that limit the chemical contamination of building air during the construction process and during occupancy of buildings are also occurring; some of these changes are specified or controlled by design professionals. However, the majority of design professionals have little or no awareness of indoor air quality considerations. There is inadequate dissemination of building science research results to design professionals. There is a need for a useful general body of knowledge, theory, and practice regarding building-environment-occupant interactions. The lack of such knowledge, theory, and practice is an impediment to developing the necessary professional design tools and practices to address effectively indoor environmental quality and energy conservation issues.