Estimates of pollutant temporal and spatial variability in commercial buildings from the joint urban 2003 field experiments

In this paper, we report on the indoor concentrations from a suite of full-scale outdoor tracer-gas point releases conducted in the downtown area of Oklahoma City in 2003. A point release experiment consisted of releases of sulfur hexafluoride (SF₆) in multiple buildings and from different outdoor locations. From the measurements, we are able to estimate the concentration variations indoors for a building operating under “typical” operating conditions. The mean indoor spatial coefficients of variation are 30% to 45% from a daytime outdoor release are around 80% during an outdoor evening release. Having estimates of the spatial coefficient of variation provides stakeholders, including first responders, with the likely range of concentrations in the building when little is known about the building characteristics and operating behavior, such as developing urban-scale hazard and consequence analyses. We show differences in indoor measurements at different distances to the release points, floors of the building, and heating, ventilation, and air conditioning system (HVAC) operation. We also show estimates at different time resolutions. The statistics show that in the studied medium to large commercial buildings, spatial differences would result in peak indoor concentrations in certain parts of the buildings that may be substantially higher than the building average. To our knowledge, very few tracer gas measurements have been conducted in buildings of this scope, particularly with measurements on multiple floors and within a floor. The resulting estimates of spatial variability provide a unique opportunity for hazard assessment, and comparison to multi-zone models.     

Adding new floors to old timber-framed buildings: An assessment of demolished and preserved courtyard houses in the historic centre of Madrid

The constructive analysis of Madrid's old timber-framed collective courtyard buildings, whether demolished, preserved intact, or enlarged, has achieved the dating of relevant case studies. New parameters established in this study set a chronology based on front sector original projects: old (1737–1788), pre-modern (1788–1847) and modern (1847–1892). The on-site inspection and archival research point to ongoing misleading construction in the historic Southern area. Some modern corralas erected on top of pre-existing buildings confirm the initial hypothesis. First dimensioning rules for new façades and the stability required in old ones before adding new storeys, maintaining the original masonry or double-layered system, are discovered. Undated buildings suggest their possible origin a la malicia and a later transformation into transitional corralas. Finally, an analysis of the demolished courtyards narrows down the dating and points to new conjectures in some preserved by showing their uneven layout, old features, and structural discordances in each sector.     

Growth,employment and the construction industry in Trinidad and Tobago

Trinidad and Tobago is a small open oil‐ and gas‐based economy that has experienced the effects of boom and bust and the associated fluctuations in income and employment. This paper focuses on the behaviour of the construction sector and its relationship to income and employment over the last three decades in this small oil‐rich economy. In the boom period the construction sector grew twice as fast as the rest of the economy. Similarly, during the recession the construction sector contracted faster than any other sector, providing proof that the multiplier operates in both directions. The correlation coefficient between construction labour productivity and per capita GDP for the period 1973–2002 was 0.70. As pertains to employment in construction per thousand population and per capita GDP, the correlation coefficient was 0.94.     

城市建设强度与热岛的相关性——以重庆市开州区为例

城市建设强度是城市热岛形成与演变的主要驱动因素,为了揭示两者之间的量化关系,以重庆市开州区为例,在用地地块、规则网格和建筑斑块3个空间尺度上,使用ArcGIS提取地表温度(LST)与建设强度指标,利用SPSS分析其相关性并构建多元回归模型。结果表明:用地地块尺度上,LST与绿化率、建筑密度和容积率之间均呈现显著的负相关,与建筑底面积和总建筑面积之间均呈现显著的正相关。规则网格尺度序列上,LST与建设强度各指标之间的相关性系数随网格面积的增大而增大,在840m网格时达到最大值;总体上LST与绿化率之间呈显著的负相关,与建筑密度和容积率之间呈显著的正相关。建筑斑块的尺度上,LST与建筑层数之间有显著的负相关关系,与总建筑面积之间有显著的正相关关系。城市建设强度直接或间接影响了城市热岛的形成与演变,而相关分析发现,建设强度指标并非都与LST之间呈正相关关系,这表明城市热岛除受建设强度的影响外,还受区域气候、城市形态、城市性质、交通方式以及建筑材质与色彩等多种因素的协同影响,是一个非线性的复杂过程。     

Generating construction schedules through automatic data extraction using open BIM (building information modeling) technology

The architecture, engineering, and construction industries have had rapid technological advancements over the last decade, particularly in the area of building information modeling (BIM). BIM stores all the information of a building and can be leveraged for many new and exciting applications including the generation of quantity takeoffs, 4D scheduling, and building simulations. The main objective in this study is to establish a framework for automating the generation of construction schedules by using data (e.g. spatial, geometric, quantity, relationship and material layer set information) stored in BIM. Using the extracted information, the proposed system in this research creates construction tasks, computes activity durations using available activity production rates, applies sequencing rules, and finally outputs a schedule. To demonstrate the functionality of this framework, a prototype system has been developed to import BIM representations with basic building elements such as slabs, walls, doors, windows, roofs, floors, and ceilings in two story buildings.     

Energy and building technology for the 2000 W society—Potential of residential buildings in Switzerland

The 2000 W society, achievable through cuts in resource consumption and per capita CO₂ emissions, is closely related to the goals of sustainable development. This study identifies the specific targets that need to be met both globally and by Switzerland to realize the vision. As a major energy consumer, the buildings sector will have to make a substantial contribution to meeting these targets. The report starts by examining the energy-saving potential of individual residential buildings through different combinations of building standard and building services system. Various building concepts already available today offer considerable potential and, as individual solutions, often achieve the targets of the 2000 W society. Yet, as the impact of such individual solutions on the building stock is dampened by a range of factors (e.g. long refurbishment cycles, low energy prices, scepticism of investors towards new technology), the effective gains fall far short of the theoretical potential. As the considered implementation scenarios and building stock projections show, the average buildings-sector targets required for the 2000 W society are nonetheless attainable. However, in order to tap the potential in the residential buildings sector, there is an urgent need for immediate action at various levels (e.g. through financial incentive systems, consumer information campaigns).     

Building codes vs. the existing housing stock‐some guidelines for energy conservation policy

Energy conservation in the housing sector has become a major policy issue since the first oil crisis in 1973–74. When mandatory building codes are used to improve the energy‐efficiency of new buildings, a high growth of construction will create a strong trend towards lower consumption per dwelling. But construction also adds new buildings to the housing stock, which will mean a higher total energy consumption, even if the marginal consumption is falling. These considerations lead to the conclusion that operating with codes is uniquely a long‐term policy in an energy conservation sense. To be able to gain short‐term conservation effects the policy measures should be directed towards existing buildings. This relation of time is not always clearly understood in the policy formulations that have been studied.     

Material stocks in Germany's non-domestic buildings: a new quantification method

The building sector consumes large quantities of resources and generates high levels of construction and demolition (C&D) waste. From an ‘urban mining’ perspective, the building stock can be seen as a repository of natural resources. In order to manage this repository, evidence is needed on its quantity and dynamics. Although data exist for domestic buildings, little evidence exists for non-domestic buildings. A new method is presented to quantify the material stock of non-domestic buildings – based on the German building stock. The quantification process involves three steps: (1) material composition indicators (MCIs) are calculated with respect to various building types; (2) the country's total floor space is estimated and disaggregated; and (3) the total material stock is calculated. The main results are MCIs and the floor space for both domestic and non-domestic stocks, as well as the material mass in total. In Germany the total material mass of non-domestic buildings is approximately 6.8 billion tonnes, accounting for 44% of the entire building stock. The method can be adapted and validated for use in other countries. These results will assist both policy-makers and the construction industry to understand the potential for moving toward a more circular economy.     

Building energy performance: sphere area as a fair normalization concept

ABSTRACT

Residential building energy performance indicators are compared with a different approach for the normalization of the characteristic yearly primary energy use. The purpose is to analyse which approach results in a fair assessment of more compact, energy-efficient building geometries, and of smaller building size. A normalization by floor area is shown to result in a poorer energy performance rating for smaller buildings. The notional building approach, as recently introduced in various countries, does not lead to a fair assessment of efficient geometries. Furthermore, the choice of reference characteristics to calculate the energy performance rating has a different impact on buildings with different characteristics. An average building approach is introduced as an improvement of the notional building approach. Form-efficient buildings are found to achieve a lower energy performance rating, but the choice of the reference characteristics is still present to a limited extent. As a second alternative, it is proposed to normalize the energy use by the sphere-area approach: the area of a sphere with the same volume as the rated building. This method leads to a fair assessment of form-efficient buildings and creates an incentive for more efficient building geometries and typologies.     

Current design guidelines’ streetscape improvement for visual perception and walkability: A case study of Sejong City,Republic of Korea

This study explores how recent design guidelines have focused on the visual variety of streetscapes making them more attractive. To date, this topic has been one of the most challenging parts of constructing walkable streets. We evaluated the streetscape features of Sejong City, recently constructed as Republic of Korea’s new capital city, and investigated their relationships with design guidelines. Consequently, we identified three principal reasons related to the design guidelines for the visual monotony in the street produced by the most up-to-date design guidelines compared with an ordinary street. First, the design guidelines cannot restrict the construction of large-scale buildings on the street, hindering visual changes caused by the zoning ordinance regulations because zoning regulations took priority when it comes to urban planning and regulatory governance. Second, design standards intending for a consistent street wall of buildings, which were used only in regard to the street enclosure standard, produced less spatial diversity and indistinct building bases, presenting weak vertical articulation. Third, applying the uniform standards for each building created repetitive architecture despite design standards for visual variety, such as recessed top floors, arcades, and retail uses for the ground floors facing a street.     

Urban planning indicators,morphology and climate indicators: A case study for a north-south transect of Beijing,China

Eleven sites, representing different urban morphologies across central Beijing, are used to simulate urban heat island effects and explore the relationship between urban planning indicators and climate indicators such as daily maximum and minimum surface temperatures. The results indicate that mesoscale urban planning indicators can explain the majority of the urban climate differences among the sites. For example, green cover ratio and floor area ratio can explain 94.47–98.57% of the variance for daily maximum surface temperature, green cover ratio and building height can explain 98.94–99.12% of the variance for daily minimum surface temperature, and floor area ratio, green cover ratio and building density together can explain 99.49–99.69% of the variance for time of peak surface temperature. Furthermore, green cover ratio is identified as the most significant urban planning indicator affecting the urban thermal environment.     

Gebäude aus Lebenszyklusperspektive – Ökobilanzen im Bauwesen

Life cycle assessment in the construction sector. Under the impression of an increasing demand for sustainability thinking in the building and construction sector, the method of Life Cycle Assessment (LCA) is constantly gaining relevance. LCA is a method to quantify and assess the environmental impacts of technical systems – in the building and construction sector, these could be both, building products or complete buildings – over their entire life cycle. In the construction sector, LCAs of building products have been well established, while LCAs of entire buildings are just now becoming more common. The German certificate for sustainable buildings strongly promotes this development by including Life Cycle Thinking into the rating of the sustainability of buildings. Due to this development, planners and other stakeholders in the construction industry have to face the necessity of life cycle based environmental optimization of a building already during the planning phase of the building. With the cooperation of LCA experts and experts in the field of assistance in the planning and construction process, dedicated and feasible solutions for this task can be developed. This article provides an overview on LCA in the building and construction sector and presents a possible approach to the question of planning‐integrated environmental optimization of buildings.     

希望大厦顶层悬挑式钢结构新工艺的研究

大连希望大厦是大连市标志性建筑物 ,共 41层 (地上 38层 ) ,高 170 6m ,是集办公、商场、餐饮、停车场于一体的多功能大厦。在原设计中顶层悬挑部分为现浇混凝土结构 ,施工难度大 ,后改用钢结构。作者对此新工艺作了有意义的探索。     

哈工大动力楼巨型框架增层结构设计与测试

哈尔滨工业大学动力楼原为两层砌体结构房屋 ,建筑面积 3 90 0m2 。根据学校发展要求 ,决定在原建筑上续建 4层。经反复论证 ,决定采用套建预应力混凝土巨型框架增层的结构方案。着重论述了基础设计、上部结构设计、套建施工方案、测试方案与测试结果分析等内容 ,相关思路和方法可供同类房屋的套建增层设计与施工参考。     

钢—混凝土混合体系结构设计和分析

福建某十层办公楼,建筑要求需在二层楼面开设大洞,开洞率占该分段单元楼层面积的56.1%;同时由于建筑平面对剪力墙的布置限制较多,仅允许布置在平面的中上方,从而导致结构布置较为严重的偏心;建筑空间上荷载较大,部分楼面活载达到12kN/m2,且布置不对称。本文通过对工程结构体系的造型比较和分析来叙述钢-混凝土混合体系在该工程的应用及其钢结构转换桁架的设计要点。     

Establishing the zero-carbon performance of compact urban dwellings

This paper presents an analysis of the zero-carbon performance of a case-study building which is representative of a growing number of new buildings that are being built on redevelopment sites in inner-city areas in the UK. Compact urban dwellings are apartment style buildings with a floor area of ～50 m² per dwelling, often based over two floors. The constraints of this type of building on achieving zero-carbon performance in the context of the Code for Sustainable Homes is discussed and the shortcomings of the code are demonstrated in terms of the target heat and electricity demand targets for the design of the building systems. A graphical representation of the simulation results is used to present the findings. It has been demonstrated that in specific urban contexts, zero-carbon performance as defined within the current UK compliance framework may be very difficult to achieve in practice given the assumptions used in the simulation here. Therefore, it is very likely that zero-carbon compact urban dwellings may require a net off-site import of electrical and/or thermal energy.     

高速铁路站点周边城市空间演变研究——以日本东海道新干线站点为例

以日本东海道新干线沿线车站为研究对象,确定站点周边半径800m为研究范围,研究时间为1964-2014年,时间跨度50年。统计了该范围的商业开发量、容积率、建筑密度空间演变相关指标,将站区发展划分为快速增长、稳定增长、缓慢增长三种类型,详细分析了不同类型代表站点周边空间演变的历程和特点,归纳出影响站点周边空间发展的因素,最后总结了相关启示,以此为我国高速铁路车站及周边城市空间的规划和建设提供参考。     

福建省城镇民用建筑能耗与社会经济发展水平的关系测算

通过统计福建省2000年～2009年城镇民用建筑能耗的情况,剖析了福建省城镇建筑能耗与社会经济发展水平的关系,并建立了单位城镇住宅建筑面积能耗、单位城镇公共建筑面积能耗与衡量社会经济发展水平的各种指标的关系函数,为预测福建省城镇民用建筑的能耗发展、科学地规划建筑节能工作,提供了基础性的统计数据和有效的数学模型.     

A matrix in life cycle perspective for selecting sustainable materials for buildings in Sri Lanka

This paper presents a matrix to select sustainable materials for buildings in Sri Lanka, taking into consideration environmental, economic and social assessments of materials in a life cycle perspective. Five building elements, viz., foundations, roofs, ceilings, doors and windows, and floors are analyzed based on materials used for these elements. Environmental burdens associated with these elements are analyzed in terms of embodied energy and environmental impacts such as global warming, acidification and nutrient enrichment. Economic analysis is based on market prices and affordability of materials. Social factors that are taken into account are thermal comfort, interior (aesthetics), ability to construct quickly, strength and durability. By compiling the results of analyses, two building types with minimum and maximum impacts are identified. These two cases along with existing buildings are compared in a matrix of environmental, economic and social scores. Analysis of the results also indicates need for higher consideration of environmental parameters in decision-making over social and economic factors, as social and economic scores do not vary much between cases. Hence, this matrix helps decision-makers to select sustainable materials for buildings, meaningfully, and thus helps to move towards a more sustainable buildings and construction sector.     

公共建筑能耗影响因素与调研分析

从建筑本体、地域、设备、行为等方面总结公共建筑能耗的影响因素。以东营市50栋公共建筑为调研对象,对被调研建筑分项能耗(空调能耗、照明能耗、设备能耗、其他能耗)占比进行箱线图分析。对4类影响因素(外墙保温、空调系统冷源形式、外窗类型、空调设置温度)对建筑能耗的影响进行箱线图分析。对于分项能耗占比:空调能耗占比波动幅度比较大,绝大部分被调研建筑的空调能耗处在较高水平,对空调系统的节能优化是降低建筑能耗的重点。照明能耗占比波动幅度比较小,虽然被调研建筑的照明能耗节能潜力有限,但仍有空间。设备能耗占比波动幅度比较大,且有较大节能潜力。其他能耗占比与照明能耗占比相似。对于影响因素:无外墙保温公共建筑的单位建筑面积能耗波动幅度更大,且单位建筑面积能耗平均水平更高。采用分体式空调器的公共建筑单位建筑面积能耗波动幅度最大,采用空气源热泵机组的公共建筑单位建筑面积能耗平均水平最高,压缩式冷水机组居中,分体式空调器最低。采用Low-E玻璃的公共建筑单位建筑面积能耗波动幅度最大,采用普通单层玻璃的公共建筑单位建筑面积能耗平均水平最高,双层中空玻璃居中,Low-E玻璃最低。空调设置温度小于26℃的公共建筑单位建筑面积能耗平均水平更高。