Journal of Architectural Engineering

With the occurrence of devastating natural disasters worldwide, even though initially used interchangeably with green or environmental development, sustainability has evolved to possess social and economic implications as well. Therefore, a complete sustainability assessment of any civil infrastructure requires an evaluation of its three major components: cost, and environmental and social impacts. Because the construction industry is a pioneer in the sustainability movement, the civil engineering community at large needs an integrated methodology for conducting sustainability assessment of civil infrastructure. This paper focuses on the environmental impact assessment component of sustainability within a comprehensive framework for conducting a life-cycle assessment of structures subjected to natural hazards. Although environmental emissions and waste generation in the initial manufacturing and construction phases make significant contributions to the total environmental impact, long-term structural performance (including damage resulting from natural hazards) plays an important role in the sustainability of a structure. The damage experienced by a structure in future natural hazards might substantially increase the total environmental impact because of repair activities. In this paper, a life-cycle environmental impact assessment methodology is proposed with specific emphasis on RC buildings subjected to earthquakes. The methodology is applied to a RC building, and the results confirm the importance of the life-cycle environmental impact assessment as an essential component of sustainability in the presence of seismic threats.

Building owners and design teams rely greatly on building energy models to identify effective strategies for maximizing building energy performance. However, past studies of building energy-model performance, particularly among Leadership in Energy and Environmental Design (LEED)-certified buildings, have shown that models can vary significantly at the individual building level. Conducting retrospective analyses of building energy models can provide more insight regarding empirical variation and models’ sources of error than past studies that reported the observed difference between predicted and actual annual energy performances. This paper describes a method for conducting retrospective analyses on building-energy models, and then applies the method to three LEED-certified dormitory buildings that are owned and operated by the U.S. Department of Defense. All three buildings contained varying levels of actual building-energy data, which served to illustrate the extent to which model error may be explained. Significant changes in building occupancy, as evidenced through building occupancy reports as well as building water-consumption data, represented the greatest source of deviation.

As a fundamental infrastructure to sustain human activities and development, urban wastewater systems are becoming more and more important in the context of population growth and business expansion. It is important to analyze and assess environmental impacts of these systems to community development. This paper presents a model developed for estimating carbon dioxide equivalent (${\text{CO}}_{2\text{e}}$) emissions resulting from urban wastewater systems addressing both construction and operational activities. Construction emissions are divided into three categories: material manufacture, material transportation, and pipe installation. Operational emissions include the following: energy consumption–related emissions and wastewater treatment–related emissions. Emission factors of gasoline, diesel oil, and electricity were calculated. The model was demonstrated by applying it to the wastewater system in the city of Suzhou, China, to quantify ${\text{CO}}_{2\text{e}}$ emissions for the period of 2005–2010. The results highlight the high proportion of emissions from material manufacturing during the construction stage and electricity usage during the operational stage. The ${\text{CO}}_{2\text{e}}$ emissions in the construction and operational phases were $517.52\hspace{0.17em}\text{t}\hspace{0.17em}{\text{CO}}_{2\text{e}}/\text{km}$ of pipe construction and $0.53\hspace{0.17em}\text{kg}\cdot {\text{CO}}_{2\text{e}}/\text{t}$ for wastewater treatment, respectively. Finally, a forecasting model was developed to predict future ${\text{CO}}_{2\text{e}}$ emissions over a 5-year horizon, which is a contribution to the overall body of knowledge in environmental sustainability.

As the sustainability of building projects has become of great concern for construction professionals, a number of different green building rating systems have been developed to help ensure that building projects are designed and built using strategies intended to minimize or eliminate their impacts on the environment. In the United States, although the Leadership in Energy and Environmental Design (LEED) green building rating system has been widely accepted as the national standard for sustainable building design, its assessment of green buildings is challenging and time-consuming owing to its complicated process. Such a green building rating process could be accelerated and facilitated by using computer technology such as building information modeling (BIM), an innovative, new approach to building design, engineering, and construction management that has been widely used in the architecture, engineering, and construction industry. To enable the green building rating for a building design in BIM applications, building information must be represented in such a way that the knowledge contained in LEED green building criteria can be extracted from the BIM model to support the assessment. In this paper, a building knowledge framework representing the LEED green building criteria will be presented. The proposed framework was implemented into a BIM platform to obtain an automated tool for the rating of a green building design. The development of the automated green building rating system and the results of its implementation will be discussed.

The building envelope plays an important role for the contributions to the whole building thermal load, especially for residential houses without significant internal heat gain; hence, it is a critical component for influencing a building’s thermal performance. However, the envelope $R\text{-value}$ is usually acquired from the original design value, regardless of the thermal insulation degrading that has occurred during the whole long lifecycle. The main reason lies in that, with traditional methods, the in situ envelope $R\text{-value}$ is extremely inconvenient to measure. In this study, a simple noninvasive approach was proposed to measure the envelope $R\text{-value}$ using the interfacial thermal resistance from the thermal boundary layer between the envelope exterior surface and the ambient air, and the envelope surface temperature measured through the infrared thermal imaging. A field measurement procedure was developed and implemented for a typical detached residential house, along with a widely accepted method using film heat-flux sensors as a validation test. The final results show a good approximation between these two tests, which shows that the proposed method could extend the functions of thermography from only qualitative diagnosis to quantitative measurement on envelope thermal performance.

Given the importance of buildings as major consumers of resources worldwide, several organizations are working avidly to ensure the negative impacts of buildings are minimized. The U.S. Green Building Council (USGBC) Leadership in Energy and Environmental Design (LEED) rating system is one such effort to recognize buildings that are designed to achieve superior performance in several areas, including energy consumption and indoor environmental quality. This paper discusses testing these hypotheses by examining LEED-certified buildings on the Arizona State University (ASU) campus in Tempe, AZ, from two different perspectives: the macrolevel and the microlevel. Heating, cooling, and electricity data were collected from the LEED-certified buildings on campus, and their energy use intensity was calculated to investigate the buildings’ actual energy performance. In addition, indoor environmental quality occupant-satisfaction surveys were administered to investigate users’ satisfaction with the space layout, space furniture, thermal comfort, indoor air quality, lighting level, acoustic quality, water efficiency, cleanliness, and maintenance of the facilities they occupy. From a macrolevel perspective, the results suggest ASU LEED-certified buildings consume less energy than regional counterparts and exhibit higher occupant satisfaction than national counterparts. From a microlevel perspective, results of the data analysis suggest an inconsistency between the LEED points earned for the energy-and-atmosphere and indoor-environmental-quality categories on one hand, and the respective levels of energy consumption and occupant satisfaction on the other hand. Accordingly, this paper showcases the variation of LEED-certified buildings’ assessment results when approached from different perspectives. This contribution necessitates consideration of the complementary macrolevel and microlevel assessments in tandem. To ensure a fair and representative LEED certification system, the authors recommend basing the awarded LEED points on the actual performance of the building during the occupation phase as opposed to the intended performance during the design and construction stages.

On the basis of known geometry, loads, and materials but with incomplete design details, the structure of a certain tall building was recreated. The first phase was a series of hand calculations to initially estimate the necessary cross sections. Then, a global finite-element (FE) model of the building was constructed and subjected to gravity and wind forces. Of particular interest were the peripheral H-shaped columns located immediately inside the glass curtain. The detailed FE buckling models of those columns were created and subjected to moderately dynamic axial loading. The analyses were carried out for an average-sized column section, and its results are discussed here. Two types of models were used in the FE work, shell and solid models. Although the magnitude of the buckling force was obviously set by the design requirements, the postbuckling characteristic was of interest, because it could play a role under some extreme loading conditions. The properties of the column material, namely, high static strength and low ductility, had a decisive influence on the postbuckling resistance.

In their assumption of a static nature for occupants’ energy-use characteristics, the conventional energy-simulation tools have failed to bring about a reliable prediction regarding changes in occupants’ behavior and the resulting impact on energy consumption. Thus, this study investigated an agent-based approach to simulating the diffusion of energy-saving policies among the occupants and the related impact on energy consumption and emission production of commercial buildings. Two different strategies were implemented in the agent-based environment to track the changes in occupants’ behavioral patterns and the consequential energy conservation by providing informational feedback to the occupants. Compared to the results obtained from energy-simulation software, the first model showed a 13% variation/reduction in building energy consumption from Year 1 to Year 3; the second model, inspired by Bass diffusion theory, showed 20% variation/reduction in the same period. The results indicate that the adoption of energy-saving policies or positive changes in occupants’ behavioral patterns of energy use may follow Bass diffusion theory in simulation of product adoption. Also, the results of both agent-based models show that there is considerable potential in energy preservation and emission reduction by providing feedback to the occupants. However, the resulting word-of-mouth effect among the occupants had a stronger influence on persuading the occupants to save energy.

A new integrated control system was recently proposed to combine double-skin façades and mass dampers in buildings to improve both building safety and energy efficiency. Double-skin façade systems protect and insulate buildings with two heavy glass layers between which air is allowed to flow for ventilation. By enabling movements in the outer façade skin, the authors proposed to (1) use them as mass dampers to reduce structural vibration and damage during earthquakes and wind storms and (2) adjust the gap size between the outer and inner skins to control the ventilation rate and improve energy efficiency. The synergy of the proposed system can lead to buildings that are structurally safe, energy efficient, and ultimately sustainable. In this paper, two structural control strategies—passive and active—are considered. The façade damper system was formulated first, and stochastic and historical earthquake responses were simulated. Then, the damper parameters (stiffness and damping coefficients) for passive control were optimized using a parametric study to minimize structural responses under earthquake excitations. Five configurations with 1, 2, 4, 5, or 10 dampers were optimized and analyzed; the optimized passive configurations can significantly reduce vibrations. Active control strategies were then applied to these five damper configurations using a linear-quadratic regulator. Different control weights were evaluated to balance performance in reducing story-to-story drifts and accelerations, and the resulting active systems outperformed their passive counterparts.

Prefabricated modular structures are increasingly becoming popular as a strategy that can be used to achieve cost-effective and speedy construction. However, there is an absence of detailed engineering research and case studies dealing with the structural performance of this technology. Although such prefabricated modules are already used for some buildings, they cannot be categorized as exclusively modular structures because a core structure is used in most of them to carry the lateral loads. This paper gives a brief overview of prefabricated modular structures and an introductory preview into an innovative structural system that can be adopted to deliver a purely modular construction. The introduced structural system was assessed through a case study of a multistory apartment building that was constructed using prefabricated modules. The static and dynamic behavior of the structure was analyzed using finite-element analysis techniques with the aid of a three-dimensional (3D) computer model. Torsional or twisting effects are a major problem for the designers of buildings. Results show that with the introduced system, the elevator shafts can be flexibly shifted around the plan without causing adverse torsional effects to the structure. The introduced technology is discussed in detail along with the key points that make it a viable option to be used in medium- and high-rise buildings.