journal article
LitStream Collection
Home
doi: 10.1002/tal.472pmid: N/A
The task of the architect has always been to find a balance between art and science, between performance and beauty. Conventionally, talking about the science of architecture has meant a discussion of building structure and systems, and the effect those elements will have on a building's interior and immediate exterior environments. We have not traditionally regarded the science of architecture as something that has a far‐reaching effect on our neighbourhoods, our cities and our planet as a whole. But now we are rapidly approaching a critical juncture in our earth's history. Pollution is threatening our environment, our air quality, our water, our very way of life. Contrary to popular thinking, it is often buildings, not automobiles that are the largest environmental offenders. This is especially true in urban areas, where buildings are responsible for as much as 80% of carbon emissions. The design community must accept responsibility for curbing the dangerous levels of pollution generated by modern buildings, and create a built environment that exists in harmony with the natural world. But we cannot move backwards. We will need to make concessions, but we cannot expect society to operate in a world without modern conveniences and comforts. Instead, we must learn to work within these parameters. The buildings of the 21st century must move beyond performing programmatically and aesthetically. They must also perform efficiently and cleanly, and be powered by natural energy. Copyright © 2008 John Wiley & Sons, Ltd.
doi: 10.1002/tal.470pmid: N/A
This paper will cover the role of the builder in delivering sustainable tall buildings. Using projects completed by Turner as examples and citing data from Turner Construction's Green Market Barometer Surveys, it will discuss the high degree of misperception on the part of decision makers about the true costs and benefits of green buildings that have, until recently, slowed the adoption of green buildings in the commercial market. It will discuss the importance and the limits of the builder's role during the pre‐construction, procurement, construction and post‐construction phases of a project, and the construction manager's ability and obligation to inform the client by providing current and accurate information on costs and benefits of green building. It will discuss progress in both raising the bar for what is possible (and at what cost) as well as raising the floor for what constitutes acceptable minimum performance in terms of legislation, regulation and market demand. It will pose questions to the design/construction/development community about how and if tall buildings individually and as part of the larger urban fabric can be truly sustainable, and if it is possible to take tall buildings from sustainable to restorative. Copyright © 2008 John Wiley & Sons, Ltd.
doi: 10.1002/tal.471pmid: N/A
Structure by its own nature is sustainable. It is all about doing more with less. Good structural engineering revolves around achieving efficiency and minimization of material. However, thinking will have to be broadened to accommodate the pressing needs of the environment. Structure can no longer stay on the sidelines and will have to be an active partner in the building‐design process. Although the architect is usually perceived as the designer of a tall building, a partnership between him/her and the engineer will have to be established before any meaningful design process can commence. This paper presents an insight into sustainable structures within tall buildings. The elements that constitute such a structure, the strategies that confirm this approach and the proposed hypothesis for the structure‐environment interaction are discussed. Copyright © 2008 John Wiley & Sons, Ltd.
doi: 10.1002/tal.475pmid: N/A
Sustainable structural engineering strategies for tall buildings are presented with an emphasis on stiffness‐based material‐saving design methodologies. The design methodologies are applied to the systems with diagonals such as braced tubes and more recently developed diagrid structures. Guidelines for determination of bending and shear deformations for optimal design, which uses the least amount of structural material to meet the stiffness requirements, are presented. The impact of different geometric configurations of the structural members on the material‐saving economic design is also discussed, and recommendations for optimal geometries are made. The design strategies discussed here will contribute to constructing built environments using the minimum amount of resources. Copyright © 2008 John Wiley & Sons, Ltd.
doi: 10.1002/tal.482pmid: N/A
Wind is often regarded as the foe of tall buildings since it tends to be the governing lateral load. Careful aerodynamic design of tall buildings through wind tunnel testing can greatly reduce wind loads and their affect on building motions. Various shaping strategies are discussed, aimed particularly at suppression of vortex shedding since it is frequently the cause of crosswind excitation. The use of supplementary damping systems is another approach that takes the energy out of building motions and reduces loads. Different applications of damping systems are described on several buildings, and an example of material savings and reduced carbon emissions is given. Wind also has some potential beneficial effects particularly to tall buildings. One is that, since wind speeds are higher at the heights of tall buildings, the potential for extracting wind energy using wind turbines is significantly improved compared with ground level. This paper explores how much energy might be generated in this way relative to the building's energy usage. Other benefits are to be found in judicious use of natural ventilation, sometimes involving double‐layer wall systems, and, in hot climates, the combination of tailored wind and shade conditions to improve outdoor comfort near tall buildings and on balconies and terraces. Copyright © 2008 John Wiley & Sons, Ltd.
doi: 10.1002/tal.480pmid: N/A
Utilizing the earth and near‐grade environment as a source of energy has historically been a common practice. Beyond solar and wind, designers do not usually look towards the sky as the source of additional benefits. The objective of this paper was to make tall‐building designers more aware of the additional sources of sustainability ‘in the sky’; how these sources change with altitude; and how this knowledge can benefit the design, construction and operation of tall buildings. Exterior environmental factors including temperature, presssure/air density, solar, wind and moisture, and their relationships with altitude are discussed. Selected approaches are suggested on how to benefit from them. Since current energy codes and ‘green’ building standards do not address the issue of enrironmental variations with altitude, the sky has potential to offer unique energy‐saving opportunities and possibly add to the quantified sustainability of a tall building. Where possible, a speculative 1‐km (3281 ft) tall tower in Dubai is used as an example for illustration. Copyright © 2008 John Wiley & Sons, Ltd.
doi: 10.1002/tal.477pmid: N/A
The service core is now acquiring an increased consideration in the design process of a tall building, since it is responsible for a great share of its energy consumption. Nowadays architecture is required to design green buildings, and the industry of high rises is strongly influenced by the ‘sustainable’ movement too. For this reason, several researches have been carried out recently, meant to lower the energy requirements of the core as a whole and of each of its sub‐components. On the contrary, little work has been done in order to assess its relevance on the embodied energy of the skyscraper. The present paper provides the author's definition for the service core, and analyzes the energy used by a tall building and the energy embodied in the materials during its construction. The author proposes several design strategies meant to lower the embodied energy of the service core. In order to assess the effectivity of alternative design strategies, the software Energy Plus has been used on a digital model of an existent building and on fictitious building having different core positioning. Copyright © 2008 John Wiley & Sons, Ltd.
doi: 10.1002/tal.474pmid: N/A
Effective use of daylighting is an essential component to achieve a sustainable building design. In a tall building, the amount of useable space with a potential for the use of daylight is the space between the exterior wall and the core. This is commonly referred to as the ‘lease span’. Class A office buildings in the USA have typically utilized lease spans of around 45 ft (13·7 m), primarily due to efficiency of space usage. In Europe, however, lease spans in high‐rise office buildings have typically been shortened due to concerns of natural light penetrations and views. For instance, in Germany, the amount of leasable space per floor is less than in the USA. The maximum allowable depth of space in Germany is typically about 18 ft (5·5 m), whereas in the USA, as much as 50 ft (15 m) is no rarity. The lease span also has an impact on other items, such as the aspect ratio, floor‐to‐floor height, total height and total floor area. In this study, to assess and predict daylight performance, two different requirements were analysed: daylight factor (DF) and the daylight requirement of Leadership in Energy and Environmental Design (LEED) 2.2 green‐building rating system. The recommended average DF (DFave) ranges from 2 to 5% and LEED 2.2 requires that a minimum daylight illumination of 25 footcandles be achieved in at least 75% of all regularly occupied areas. This study conducted a series of computer simulations using RADIANCE to first show the effects of each of the fenestration parameters and then to provide an optimum effective aperture to meet the two daylight requirements in four lease span types ranging from 20 to 50 ft. As a final step, regression models and simple evaluation tools were developed to correlate the DF, daylight requirement in LEED 2.2 and the various fenestration parameters, such as window area, visible transmittance and lease span in four different cities (London, Chicago, Dubai and Bangkok). This paper provides a simplified method for evaluating indoor daylight performance to meet the two daylight requirements. This can be used as a pre‐design tool, not only to achieve more credits in LEED 2.2 green‐building rating systems, but also to evaluate based on DFave to ensure that the building meets the recommended level. Copyright © 2008 John Wiley & Sons, Ltd.
doi: 10.1002/tal.481pmid: N/A
All buildings with noise‐sensitive spaces, and residential occupancy in particular, require noise mitigation to be incorporated throughout the architectural, structural and building services design. For tall buildings, the number and type of noise and vibration sources increase, particularly where sustainable design features are incorporated, such as natural ventilation, that can reduce the acoustic performance of facades. Additional noise sources located on and near the facade of a building and the reduced noise isolation afforded by the facade have a detrimental effect on the acoustical amenity within the occupied spaces. This paper reviews noise source identification and mitigation for tall buildings, and considers additional acoustic issues associated with green buildings. In particular, approaches to achieving improved noise transmission loss performance across facades, and the identification and mitigation of the effects of noise and vibration sources located internal and external to the building are considered. Copyright © 2008 John Wiley & Sons, Ltd.
Showing 1 to 10 of 11 Articles