Integrated life-cycle design of building enclosures

In spite of the progress in developing methods and tools to support sustainable building design, there is still a lack of a formal approach to bridge the “no man’s land” gap between the traditional building engineering disciplines, and between these and the architecture, to achieve the level of building integration required for sustainability. This paper presents an integration framework that aims at facilitating the inclusion of life-cycle considerations in the design process from the outset, so that materials and systems are selected not only from environmentally friendly resources, but most importantly, to match service life performance expectations. The framework describes an iterative methodology to evaluate these expectations in practice, which is based on an understanding and modeling of the dynamics of the built environment to which materials, components, and systems are exposed. Quantitative methods and test protocols can be incorporated into the framework for assessing function-performance aspects of alternative solutions. Due to its complexity stemming from its inherent exposure to variable environmental loads and its multi-functionality, the framework focuses on addressing the life cycle of the building enclosure system. It is expected that the organization of the underlying principles of building life-cycle performance described in this paper will become a knowledge core that will facilitate a more integrated treatment of buildings in research, education, and practice.     

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.     

Theory of valuing building life-cycle investments

The physical adaptability of buildings is very important in today's fast-changing business environment. The actors who invest in long-term adaptability are positioned better to the changes during the life cycle of a building. This conceptual paper argues that the current dominating real estate (property) investment analysis theories do not accommodate enough building design-related information (i.e. physical asset characteristics), which results in long-term loss of competitiveness and unsustainable use of built environment resources. It is demonstrated that physical asset characteristics can create valuable real options that should be acknowledged in real estate investment analysis and management. The real estate investment literature has not so far been able to produce a widely accepted financial model for justifying life-cycle investments. A theory is proposed here that can be used to value life-cycle investments in buildings. This new theory combines of real options valuation, investment analysis and building component life-cycle design. These themes are used to formulate a conceptual framework for valuing life-cycle investments. The framework is intuitive and transparent, and it can be easily added to current spreadsheet investment analysis tools.     

高层建筑全寿命周期的消防安全管理体系

总结我国高层建筑防火管理存在的缺陷.针对我国城市高层的防火问题,在借鉴国外先进经验的基础上,建立一套高层建筑全寿命周期的火灾防控安全管理体系.为加强其执行力度,运用社会各方参与立体化管理模式,研究高层建筑常规使用、非常规使用等不同状态下的动态管理.     

Environmentally sustainable development: a life-cycle costing approach for a commercial office building in Melbourne,Australia

A range of property and construction options is analysed using standard life-cycle costing methodology. The options are to renovate the existing building, buy an alternative building and renovate, and buy a development site and construct a new building. The do-nothing option and a hypothetical option to construct a new building on an ideal site are analysed as benchmarks. The results show that the optimum option is to buy a suitable site and construct a new building and that the least sustainable option, in the case study, is to stay in the existing property and renovate the building. Although staying in the existing building and doing nothing carries the lowest financial cost, energy consumption and greenhouse emissions are significantly worse than for the alternative options.     

Equipment reliability: a life-cycle approach

The dawn of the new millennium has seen a radical change in the manufacturing sector, where more and more companies are moving towards globalisation, restructuring and downsizing strategies. The impetus of this transformation has triggered organisations to reduce the manufacturing costs and produce more for less by making their plans increasingly reliable. Equipment reliability is not just another fad, or a buzzword, it is a competitive advantage in today's global environment. Many companies are now developing reliability strategies at corporate levels rather than just dealing with plant maintenance activities at shop floor level. The overall objective of this article is to show that a simple model can help reliability practitioners to develop a comprehensive reliability strategy. This also gives them an insight into some of the tools and techniques that are essential in achieving the right strategy     

论全生命周期造价管理在建筑设计中的应用

在分析全生命周期造价管理在建筑设计中应用的必要性及重要意义的基础上,从建设方案、造价计算、BIM技术三方面,探讨了建筑设计中全生命周期造价管理的具体措施,旨在为提升我国建筑设计的全生命周期造价管理水平提供参考。     

A novel approach for building occupancy simulation

Building occupancy is an important basic factor in building energy simulation but it is hard to represent due to its temporal and spatial stochastic nature. This paper presents a novel approach for building occupancy simulation based on the Markov chain. In this study, occupancy is handled as the straightforward result of occupant movement processes which occur among the spaces inside and outside a building. By using the Markov chain method to simulate this stochastic movement process, the model can generate the location for each occupant and the zone-level occupancy for the whole building. There is no explicit or implicit constraint to the number of occupants and the number of zones in the model while maintaining a simple and clear set of input parameters. From the case study of an office building, it can be seen that the model can produce realistic occupancy variations in the office building for a typical workday with key statistical properties of occupancy such as the time of morning arrival and night departure, lunch time, periods of intermediate walking-around, etc. Due to simplicity, accuracy and unrestraint, this model is sufficient and practical to simulate occupancy for building energy simulations and stochastic analysis of building heating, ventilation, and air conditioning (HVAC) systems.     

基于全寿命周期的体育建筑可持续发展研究

简述了可持续发展的体育建筑的含义与特点,对全寿命周期体育建筑的可持续发展策略进行了研究,并从规划、设计、施工、运营、拆除五个阶段作了论述,以实现体育建筑的可持续发展。     

A holistic approach to energy efficient building forms

Minimizing energy consumption in buildings has become an important goal in architecture and urban planning in recent years. Guidelines were developed for each climatic zone aiming at increasing solar exposure for buildings in cold climates and at reducing solar exposure for buildings in hot climates. This approach usually plans for the season with the harshest weather; often forgetting that temperatures in cities at latitude 25° can drop below thermal comfort limits in winter and that temperatures in cities at latitude 48° often rise above thermal comfort limits in summer. This paper argues that a holistic approach to energy efficient building forms is needed. It demonstrates a generic energy efficient building form derived by cutting solar profiles in a conventional block. Results show that the proposed building form, the Residential Solar Block (RSB), can maximize solar energy falling on facades and minimize solar energy falling on roofs and on the ground surrounding buildings in an urban area in winter; thus maximizing the potential of passive utilization of solar energy. The RSB also supports strategies for mitigating the urban heat island through increased airflow between buildings, the promotion of marketable green roofs and the reduction of transportation energy.     

A product modeling approach to building knowledge integration

Knowledge informatics is still playing only a minor role in the design process of buildings and civil engineering efforts, particularly in the inception stage. The primary reason that most knowledge tools are not well integrated into the process is that most tend to be based on stand alone expert system technology. Improving the re-use of existing knowledge is required to increase industry performance. A solution could be a new generation of integrated knowledge systems. One problem that must be addressed is how to cope with the conflicting requirements of each particular subsystem when each is optimized for its own knowledge domain. No optimum solution exists that is able to simultaneously optimize each subsystem for a total solution. This paper discusses an approach to building knowledge integration that attempts to address these shortcomings through the use of combined product model and meta-knowledge approach.     

A mini-scale modeling approach to natural daylight utilization in building design

This paper purposes on shading devices as natural daylight utilization component for building design. It was proved that a proper setting for shading device could conspicuously promote the room lighting performance. Natural daylight which includes directional sunlight, diffused skylight and reflected light can also exert as a perspective of energy conservation in buildings. In order to verify a simple approach can also be workable, a mini-scale model (1:20) is employed in this study. It reveals that when a suitable altitude and azimuth is maintained, in regards to the vertical shading device and the sun position, not only is shading achieved, but the area of the daylight zone can also be substantially increased. The experiment investigated and analyzed the details of this modeling data and subsequently proposed relevant design criterion for vertical shading devices that both users and designers can apply. Namely, it proved that a mini-scale model could also assist in natural daylight utilization and building energy-conservation design.     

基于全生命周期的建筑节能多级模糊综合评价分析

讨论了基于全生命周期的建筑节能多级模糊综合评价的相关问题,以求为未来建筑节能设计提供理论支撑,分析了全生命周期建筑节能评价指标体系的构建方法,探讨了全生命周期建筑节能评价指标的相关内容,最后建立多级模糊综合评价模型,对建筑节能的相关问题进行评述。     

A combined CFD-HAM approach for wind-driven rain on building facades

Numerical heat-air-moisture (HAM) transfer models are increasingly being used to study the hygrothermal performance and the durability of building facades. One of the most important boundary conditions for HAM simulations is wind-driven rain (WDR). Due to the complexity of WDR, however, the current HAM models generally incorporate it in a very simplified way. Recent research has shown that CFD can provide quite accurate estimates of the spatial and temporal distribution of WDR on building facades. Therefore, in this paper, a combined CFD-HAM approach is presented. It consists of implementing catch-ratio charts resulting from CFD simulations into the HAM model. Within the model, these charts are used to convert the standard meteorological input data (wind speed, wind direction and horizontal rainfall intensity) into WDR distribution records that are used as boundary condition for the actual HAM simulations. The combined approach is demonstrated for a simplified wall model. It is shown that the accuracy of the HAM-simulation results is to a large extent determined by the time resolution of the meteorological input data and by the data-averaging technique used for these data. Some important guidelines for accurate HAM analyses with WDR are provided.     

A multicriteria lifespan energy efficiency approach to intelligent building assessment

This paper presents a multicriteria decision-making model for lifespan energy efficiency assessment of intelligent buildings (IBs). The decision-making model called IBAssessor is developed using an analytic network process (ANP) method and a set of lifespan performance indicators for IBs selected by a new quantitative approach called energy–time consumption index (ETI). In order to improve the quality of decision-making, the authors of this paper make use of previous research achievements including a lifespan sustainable business model, the Asian IB Index, and a number of relevant publications. Practitioners can use the IBAssessor ANP model at different stages of an IB lifespan for either engineering or business oriented assessments. Finally, this paper presents an experimental case study to demonstrate how to use IBAssessor ANP model to solve real-world design tasks.     

A parametric approach for performance optimization of residential building design in Beijing

During the early design stage of green residential buildings, there are tremendous potential of using parametric optimization to achieve preferable green performance, such as building energy consumption efficiency, daylighting, ventilation and thermal comfort. Taking residential design features into consideration, this paper presents an optimization workflow and effects based on a case study of a residential building project in Beijing. Firstly, 27 design parameters related to residential spatial form and building envelope were selected for the optimization. The simulation results of the cooling and heating load were taken as the optimization objects. Secondly, optimized schemes were obtained from 6246 simulation results, with 1925 verified simulation results proving that the optimized result is reliable. Finally, analysis was performed to establish the correlations between design parameters and performance in order to create the easy access for architects to determine design parameters depending on the performance sensitivity of each parameter. Analysis results showed that parametric optimization of spatial form and building envelope at the design stage is a feasible approach to reducing energy consumption in residential building design.

     

Modelling perceptions of building quality—A neural network approach

The conceptual framework for this study was based on the premise that there are lifestyle groups within a culture which commonly share attitudes and perceptions which are reflected in the form and design of their buildings. This study focussed on a particular lifestyle group of people from the same ethnic background, i.e. Caucasian of European ancestry who owned and lived in detached houses. The sample of participants were homogenous in terms of their ethnic background and houses. The setting of this study was a residential estate in Townsville, Queensland, Australia, a hot-humid environment. This study used the ethnographic approach of case study methodology; hence, data were gathered from questionnaires, interviews, observations, building plans, notes and photographs. The attitudes and perceptions of the selected group of homeowners on the quality of their houses in six areas of building performance: spatial, thermal, acoustical, visual, building integrity and indoor air quality, were investigated. The data were qualitatively analysed, assembled and manipulated in a computer-based model. In developing the computer-based model, the capabilities of the programming paradigms—conventional programs, knowledge-based systems and learning systems, were investigated. A neural network learning system was chosen for developing the computer-based model. The neural network model was tested and validated on example cases of houses to verify its prediction capability.     

A state machine approach in modelling the heating process of a building

Process models and their applications have gradually become an integral part of the design, maintenance and automation of modern buildings. The following state machine model outlines a new approach in this area. The heating power described by the model is based on the recent inputs as well as on the past inputs and outputs of the process, thus also representing the states of the system. Identifying the model means collecting, assorting and storing observations, but also effectively utilizing their inherent relationships and nearest neighbours. The last aspect enables to create a uniform set of data, which forms the characteristic, dynamic behaviour of the HVAC process. The state machine model is non-parametric and needs no sophisticated algorithm for identification. It is therefore suitable for small microprocessor devices equipped with a larger memory capacity. The first test runs, performed in a simulated environment, were encouraging and showed good prediction capability.     

基于经济投入-产出生命期评价模型的我国建筑物化能与大气影响分析

在我国城市化进程加速与基础设施大规模建设的社会发展背景下,研究建筑物化能消耗量及其所导致的大气污染物排放量。从全社会经济活动的角度出发,以建筑生命期为主线,建立并运行经济投入-产出生命期评价模型,比较和分析建筑物化能的来源与组成,量化主要大气污染物的排放。此外,对建筑物化能与大气影响进行预测分析,并为建筑节能减排工作提出对策与建议。研究结果表明:建筑物化能约占我国社会总能耗量的16%,因此对其研究不可忽视;各类能源在消耗过程中所释放的有害气体,是我国大气环境的重要污染源;若继续2002年的产业关联状况水平,2015年我国建筑物化能及其大气污染物在全社会总能源消耗和污染物排放中的比重将持续上升。研究成果丰富了全生命周期评价模型在我国建筑领域的应用,完善当前的相关统计数据,为我国广义建筑能耗与环境影响问题提供计算方法和数据支持,同时也为政府主管部门制定相关政策提供理论参考与依据。