Journal of Architectural Engineering

The process of constructing a sustainable green building presents a number of challenges compared with regular buildings. Additional work and documentation is needed in every stage of the project life cycle for the sustainable building to reach its goal of being certified according to one of the available sustainability rating systems. One of the most important steps toward achieving that goal is the eco-charrette process that takes place during the predesign phase of the project. The importance of this step stems from the fact that it sets the sustainability goals and objectives for the entire project. This necessitates the creation of an effective decision support methodology that will support project stakeholders in setting the sustainability goals and objectives of the project before committing valuable time and budget resources to the eco-charrette process. Therefore, this paper presents the development of an agent-based model for simulating the interactions between project stakeholders in the sustainability goal and objective setting process of the project predesign phase. The proposed model was developed based on extensive interviews with industry professionals and project stakeholders, and was tested and validated using a case study of an institutional building project. Simulation results were shown to closely resemble the actual case studies evaluated and highlighted the sensitivity and relationships of building design parameters.

Digitally addressable lighting systems offer tremendous opportunities for performance monitoring and control of individual light fixtures. However, the locations of individual light fixtures within a building are not easily differentiable; as such, facility managers cannot distinguish and control each fixture. Virtual models contain semantic representations of objects that enable users to visually identify, distinguish, and interactively monitor building components, thus providing opportunities for controlling components. To monitor and control light fixtures from these models, each physical fixture needs to be tightly integrated with its virtual representation in order to enable bidirectional coordination. Bidirectional coordination between virtual models and physical light fixtures offers tremendous opportunities for enhancing progress monitoring during construction and performance monitoring and control during the operations and maintenance phase of a building’s life cycle. This paper presents an approach to facilitating this through cyber-physical systems integration between virtual models and physical light fixtures. The importance of actively monitoring and controlling light fixtures is highlighted. A cyber-physical systems architecture that illustrates the key features, enabling technologies and their roles, is presented. The paper also presents a prototype system that has been developed and implemented to demonstrate the functionality of the proposed approach.

Quality designs generally emerge from a conceptual design process that generates and communicates large design spaces of objectives, alternatives, impacts, and values. Parametric modeling is a popular means for generating large alternative spaces; however, it is difficult to use effectively when the other spaces are not well generated. In this study, a framework for measuring design space clarity and quality is applied to traditional nonparametric practice—and to two applications of parametric modeling—on high-rise projects. The framework reveals deficiencies in both the quality and clarity of the design spaces that building designers are able to construct using traditional and parametric methods. A fourth industry case study illustrating the application of a formal methodology called design scenarios developed to address these shortcomings is described. The case studies illustrate the potential for significant impact that parametric modeling can have on the overall conceptual design process performance, particularly when supported by methodologies that better generate and communicate design spaces.

The primary advantage offered by the Eco-indicator 99 (EI99) methodology is its ability to consider life cycle assessment (LCA) uncertainties. EI99 considers these uncertainties through a perspective-specified set that includes egalitarian/egalitarian (e/e), hierarchist/hierarchist (h/h), and individualist/individualist (i/i) methodological options, along with a perspective-averaged set that includes individualist/average (i/a), egalitarian/average (e/a), and hierarchist/average (h/a) methodological options. These two sets of options are based on a cultural theory framework that was initially intended for different areas of interest. The objective of this study was to determine the robustness of EI99 for the environmental evaluation of building technologies under LCA uncertainties. A split-unit design was used to determine the robustness of EI99 for evaluating four reinforced concrete technologies and four masonry structure technologies. A significant disordinal interaction was observed between the two methodological sets evaluated by EI99. The h/h and h/a options were considered to fall within the same area of interest. Different rankings for the building technologies were obtained using the different EI99 methodological options. A full set of EI99 methodological options should be used by building designers and practitioners to determine the impact of a preferred decision on the initial construction cost, the life-cycle cost, the embodied energy, occupant health, and resource and/or habitat conservation.

Bayesian and nonlinear least-squares methods of calibration were evaluated and compared for gray-box modeling of a retail building. Gray-box model calibration is one form of system identification and is examined here with perturbations to the simple yet popular European Committee for Standardization (CEN)-ISO thermal network model. The primary objective was to understand whether the computational expense of probabilistic Bayesian techniques is required to provide robustness to signal noise, specifically with regard to lower dimensional problems (physical or semiphysical), where model calibration is preferred over uncertainty quantification. The Bayesian approach allows parameter interactions and trade-offs to be revealed, one form of sensitivity analysis, but its full power for uncertainty quantification cannot be harnessed with gray-box or other simplified models. Surrogate data from a detailed building energy simulation program were used to ensure command over latent variables, whereas a range of signal-to-noise and noise colors were considered in the experimental study. The fidelity to the building zone temperature and thermal load was the basis for comparing results. Utilization of uniform priors showed that both methods performed similarly well. Bayesian calibration outperformed traditional methods on noisy data sets; however, traditional methods were adequate up to an approximately 25% noise level. The thermal gray-box model calibration has the intended application of embedded model predictive control, where speed, accuracy, and robustness are crucial. Traditional methods required approximately 100 times less CPU time and are recommended given the model simplicity, application, and expected system noise levels.

The growing complexity of buildings requires architectural engineering to integrate many different specialized capabilities, among which building physics often plays a primary role. Architectural engineers must understand all building systems and be able to apply physics principles to the building envelope and indoor environment. This paper discusses the content and educational approaches of two new courses, Building and Architectural Acoustics and Building Electrical and Lighting Systems, in the new architectural engineering program at Worcester Polytechnic Institute (WPI). For both courses, teaching through project-oriented education presents unique challenges. The projects the classes focused on included optimizing the lighting design at the Worcester Art Museum and the acoustic design in WPI classrooms. This hands-on approach, focusing on both actual measurements and simulations, encourages students to develop a professional attitude for applying theoretical principles to the solution of engineering problems and trains them in the use of state-of the-art tools. Finally, the extension of these experiences to other courses is discussed.

Integrated buildings are one goal of the architectural/engineering/construction (A/E/C) community. Integration implies quality work and it is perceived to add value to a project; but, how is integration defined and how is it applied? This paper reflects on the current status of integration and assesses where the industry stands. To do this, integration was evaluated through publicly available documents of the major professional organizations that represent the field. The American Institute of Architects; ASCE; two ASCE institutes (Structural Engineering Institute and Architectural Engineering Institute); the American Society of Heating, Refrigerating and Air-Conditioning Engineers; and the Associated General Contractors of America were examined for their commitment to and implementation of integration and integrated design. This survey of the resources has found that integration is important to the industry on the whole, but that the effort to include integration into the A/E/C industry varies in commitment by discipline. However, while there is unevenness in the industry toward integration, there is movement to address the complex idea of integration and changes are ongoing.

Precast concrete load-bearing wall panels have been used for decades with unparalleled success due to their architectural versatility, thermal insulation, ease of production and erection, and structural performance. According to the current building code, structural walls do not need transverse ties if the vertical reinforcement ratio is less than 1% or when vertical reinforcement is not required as compression reinforcement. Also, minimum reinforcement requirements do not apply to structural walls with an average effective prestress of 1,551 kPa (225 psi) or greater. Elimination of transverse ties in structural precast walls simplifies the production of the panels. The presence of large openings in precast walls is very common in the design of modern buildings. This results in a significant reduction of the panel cross section. Most designers tend to design the remaining portion of the panel cross section as a column and not a wall, which requires minimum transverse ties according to the current building code in the United States. The requirement could complicate wall detailing and reduce the efficiency and economy of panel fabrication. This paper summarizes the literature review conducted to determine when precast load-bearing walls should be designed as columns/walls with respect to transverse reinforcement. The requirements of transverse reinforcement in walls and columns in various building codes were studied, and design recommendations were made.