Journal of Architectural Engineering

The urban heat island (UHI) effect has detrimental impacts on building cooling demand, public and ecological health, and climate change. Because UHIs are caused by the concentration of construction materials that absorb and retain heat, buildings in urban areas present challenges and opportunities to mitigate them. Specifically, innovative building skin solutions, such as those covered with smart materials (SMs) that respond to environmental stimuli with their dynamic time and temperature-dependent behaviors, have significant potential to reduce the UHI effect. This research provides a review of the state-of-the-art applications of SMs in building skins for urban heat island mitigation (UHIM). It highlights the knowledge gaps and opportunities for future research with an extensive literature review and in-depth analysis. This research classifies the application of skin-integrated smart materials (SISMs) for UHIM into five main groups that included thermal, light, air pollution, humidity and ventilation control, and energy generation, and highlights their challenges and prospects.

Mass timber (MT) is an engineered wood product that has been widely used in Europe and is rapidly gaining popularity in the United States (US). MT structural members consist of multiple wood components connected using adhesives and/or mechanical fasteners. Although wood is a common material in the US, MT is not readily available in the US. Some US structural engineers are reluctant to include MT as a potential construction material in their building designs due to limited MT material availability, cost, and unfamiliarity with MT as a construction material. This unfamiliarity stems from limited US MT education and lack of MT experience at the professional level. This paper attempts to provide a broad-brush MT review for architects and structural engineers interested in incorporating MT in their designs on relevant standards and specifications. Guidelines for designing with MT are provided in the International Code Council’s 2024 International Building Code (2024 IBC) under “Type IV Construction.” The Type IV construction description was initially greatly expanded in the 2021 IBC to allow for tall MT buildings and continues to be included in the 2024 IBC. This paper identifies and reviews the 2024 IBC criteria related to MT. Additionally, discussion is included on military standards pertinent to MT. The composite action of an MT element is highly dependent on the adhesive behavior used to attach the MT member laminations. Consequently, adhesives used with MT members and the testing protocol to validate satisfactory adhesive behavior are discussed.

This study researches the development of a multiobjective optimization environment to continue the investigation of the potential for housing in Toronto to meet Passive House certification. BEopt (Building Energy Optimizer) was used to develop various deep energy retrofits for Century detached, Century-semi, and Wartime archetype homes in Toronto, ON. The optimization environment used various design retrofits to develop configurations of variables which minimize energy use and life cycle cost. The developed solutions were input into WUFI Passive to determine which combination of variables can achieve Passive House certification for the lowest life cycle cost. The optimization results demonstrated that for a life cycle cost of $65,053–$92,950 depending on geometry and housing type, an archetype home in Toronto can reduce energy use by 69%–72% and can meet standards for Passive House. Although the developed numbers include average pricing data, assumptions, and generalizations, the findings of this research demonstrate the applicability of high-performance building standards in retrofit strategies. Through the adoption of energy efficient deep energy retrofits in existing homes, sustainability in the built environment can be achieved.

Amidst the prevailing subjective pricing paradigms for high-rise apartments in India, this paper advocates for a paradigm shift toward thermal comfort–based differential pricing, recognizing its pivotal role in influencing residents’ well-being in hot and humid climates and energy savings. Understanding the correlation between thermal comfort, floor level, and orientation can lead to implementing such pricing strategies. Three models are proposed through market surveys and simulations, incorporating thermal comfort and other existing market preferences using Hedonic regression and two models using the analytic hierarchy process. The comparison reveals that Model 1, based on buyers’ preferences, yields a 0.72% mean improvement in the total sale price, Model 2, focused on thermal comfort, sees a mean increase of 0.86%, and Model 3, incorporating both thermal comfort and buyer preferences, results in a mean increase of 2.22%. The study emphasizes the significance of a multicriteria-based pricing model for high-rise apartments with thermal comfort as the focus, highlighting its flexibility to accommodate diverse criteria and determine suitable differential prices by adjusting percentage priorities based on specific requirements.

Earthquake catastrophes continue to cause substantial damage and casualties in many parts of the world. Despite design codes and standards having succeeded in reducing life losses during earthquakes, the level of damage in buildings after severe earthquakes still cannot be precisely predicted. Code provisions focus on the safety of buildings with no consideration of the amount of damage expected after an event. Current U.S. guidelines designate three performance levels related to the inelastic rotational demands of RC shear walls––immediate occupancy, life safety, and collapse prevention. The damage corresponding to these performance levels is minor, moderate, and severe, respectively. In the current study, these performance limits were implemented, along with other recognized standards, in order to design four RC ductile shear wall buildings with different heights located in a high seismic hazard zone. Each building was designed based on Canadian building codes to reach the three designated performance levels. For each case, the quantities of the constitutive materials of the RC shear walls were estimated and compared. The impact of the targeted performance level on the building’s gravity-load-resisting system was also investigated. The cost effectiveness of using moderately ductile shear walls in high seismic hazard zones was also examined.

Combined usage of computer-aided design (CAD) and building information modeling (BIM) in the same construction project can result in unwarranted issues. Stakeholders might combine CAD and BIM due to a lack of awareness of the benefits of implementing BIM exclusively. A lateral comparison between the impact of CAD and BIM on different project activities can provide stakeholders with the necessary awareness. Therefore, this study aimed to compare the task performance of BIM and CAD in completing different construction project activities in a controlled environment. To achieve that, this study used an experimental lab research approach. The study participants were industry professionals with experience in using CAD and/or BIM to produce different project outputs. The outputs were analyzed to identify shifts in task performance among the participants, including mean and median analysis and ANOVA. The results, encompassing duration, completeness, and accuracy, highlight BIM’s superiority over CAD. Extrapolating these results to overall task performance, BIM exhibits approximately two times better performance than CAD. The study reveals that BIM’s integrated and dynamic modeling approach contributes to its superior performance, enhancing accuracy, completeness, and efficiency in construction project activities. As a result, the study emphasizes the importance of using BIM exclusively. Nevertheless, this is the first study that laterally compares the performance of BIM and CAD in completing different construction project activities in a controlled environment.

Delivering project value primarily depends on understanding project stakeholders' different needs and requirements and translating these needs into a well-constructed facility. This concept is usually insufficiently revealed using different terminologies during the educational journey of architecture, engineering, and construction (AEC) professionals. The goals of this research are to (1) investigate students' and practitioners' familiarity and knowledge about the concept of value, (2) explore underlying gaps in teaching value in AEC education, and (3) propose essential practices to overcome identified educational shortcomings. For this purpose, combined qualitative and quantitative approaches were used to evaluate responses by students and practitioners, including a structured survey, interviews, and statistical analysis. The paper introduced a framework for educational content that supports value delivery using lean principles, design thinking, sustainability, and digital collaborative technologies. The survey and interviews revealed a major deficiency in students' and practitioners' familiarity with the concept of delivering value and the tools needed to enhance it. Thus, a knowledge gap about delivering project value was identified in AEC curricula. Additionally, cross-disciplinary engagement and collaboration efforts were found to be insufficient. Students and practitioners revealed doubts about the relevance of academic projects. Nonetheless, participants confirmed the importance of providing a better understanding of the value concept and related practices. The proposed framework for better incorporating the value concept into AEC curricula has the potential to improve project outcomes and satisfaction in the AEC industry.

As is known, the propagation of cracks in a structural member is associated with local modifications of rigidity and thus possible major effects that can strongly affect its load-bearing capacity and dynamic parameters. As such, among others, the natural frequency control represents a consolidated and efficient approach for damage detection, damage severity assessment, and in situ monitoring for several structural typologies. In this paper, attention is given to typically brittle-in-tension structural glass members and to the analysis of first-crack initiation in terms of natural frequency decrease. The goal is to assess the potential and feasibility of a standardized approach for in situ structural health monitoring (SHM) assessment. To this aim, the investigation takes advantage of a literature analytical model for frequency assessment (i.e., as a function of crack position and depth), and of finite-element (FE) numerical simulations carried out to predict the cracked vibration frequency of various configurations of technical interest. As a first step of this possible methodology assessment, glass beams under an in-plane bending setup are considered, given that they are largely used as stiffeners or fins. It is shown that while glass material is typically brittle in tension and cracks can originate from edges due to several reasons, traditional frequency-based monitoring tools can be efficiently adapted for early detection and to quantify damage in existing glass structures. For the examined configurations, it is shown that frequency reductions up to ≈−20% can be expected due to first-crack initiation. Most importantly, the FE numerical analyses show that crack shape/geometry can further emphasize the expected frequency decrease, and thus additionally enforce the need of specific protocols/performance indicators for SHM purposes in existing structures, as well as for the optimal design of new systems.

Glass curtain walls, while broadly used as a building facade, are vulnerable to extreme winds. Curtain-wall failures in major wind events lead to substantial economic losses, and wind-induced vibration is often a major contributing factor to such failures. The main objectives of this study are to (i) present high-fidelity numerical modeling techniques to reproduce the wind-induced dynamic behavior of building facades, specifically focusing on a single-skin curtain-wall system, and (ii) highlight the impact of the interaction between facade and building structure on the wind-induced dynamic behavior of the curtain-wall system. The developed finite-element model is calibrated for a particular wind scenario tested at the Natural Hazards Engineering Research Infrastructure (NHERI) Wall of Wind Experimental Facility (WOW EF) at Florida International University (FIU), and subsequently validated to assess whether it can realistically reproduce the dynamic behavior in different scenarios involving various wind speeds and directions. This study also uncovers that the interaction between the facade and the building structure plays an important role in governing the wind-induced dynamic behavior of the curtain wall. In addition, this study finds that the presence of a vertical protrusion, attached to the facade for architectural reasons, may negatively impact the wind-induced dynamic response of the curtain wall, with this impact being influenced by the interaction between facade and structure. This study reports the significant discoveries, contributing new insights to facade design and the engineering industry.

This research focuses on schools due to their significant energy consumption. It explores the use of well-designed unshaded courtyards as a passive design strategy in hot climate regions, an area that has received limited attention. The research methodology combines a qualitative approach, case study, and computer simulations through ENVI-met and Integrated Environmental Solutions Virtual Environment (IESve) software. The case study involves an existing school building in the hot arid climate of the United Arab Emirates (UAE). The ENVI-met software evaluates changes in the school’s microclimate and building temperature resulting from modifications to the courtyard’s design, encompassing five phases. Moreover, the research employs the predicted mean vote (PMV) metric to assess outdoor thermal comfort within school courtyards, correlating with the five design phases. The IESve software assesses the reduction in cooling sensible load achieved through improved courtyard design in the case study. The simulation results demonstrate that the optimal courtyard design lowers the school building’s temperature by 1.9°C and 1.7°C on September 21 and March 21, respectively, compared with the base case. Furthermore, it enhances PMV within the courtyard, providing students with a more comfortable outdoor environment during breaks, with maximum PMV reductions of 1.2 and 1.1 on September 21 and March 21. In addition, the optimal courtyard design achieves a significant reduction in cooling sensible load, showing a 19% decrease on September 21 and a 27% decrease on March 21, compared with the basic case. These findings underscore the potential of well-designed courtyards to enhance thermal comfort and energy efficiency in schools within hot arid climates, contributing to sustainable architectural practices.

The recent advancements in theories and numerical methods of engineering optimization have paved the way for the widespread application of computational techniques in architectural and structural design, as well as software development. This paper is focused on exploring the practical implementation of various optimization strategies within architectural and structural design contexts. By utilizing mesh generation algorithms, intricate geometries inherent to architectural and structural design can be systematically constructed and discretized, facilitating analysis, design, and optimization processes. In the domain of grid-shell design, achieving optimal and aesthetic forms while adhering to engineering constraints is essential. This research explores grid-shell form finding and optimization, using a potential energy-based algorithm to reach equilibrium in grid-shell structures. Subsequent size optimization addresses stress and buckling concerns to ensure structural robustness. For long-span structures, often desired for their creation of expansive spaces and incorporation of architectural design principles, structural performance optimization is achieved using topology optimization. This study explores multiple manufacturing constraints embedded within topology optimization to enhance the feasibility of realizing topologically optimized material configurations. Another area of engineering optimization is in roof truss and frame design, aimed at creating distinctive and aesthetically pleasing configurations beyond traditional forms while meeting engineering load combinations and design criteria. To generate unique forms for roof truss structures, the genetic algorithm is employed in this study. This algorithmic approach facilitates diverse geometrical configurations while maintaining required strength and serviceability criteria. Through these studies, the paper highlights the transformative potential of optimization methodologies in shaping innovative architectural and structural designs with enhanced efficiency and functionality.

Mass timber panels including cross-laminated timber (CLT), dowel-laminated timber (DLT), and nail-laminated timber (NLT) are used increasingly as floor slabs in mass timber buildings and hybrid timber buildings. The sound insulation performance of bare mass timber structural floors is insufficient due to their lightweight and relatively high bending stiffness. Floating concrete toppings are commonly applied for improved sound insulation performance with an elastic interlayer. The effect of different elastic interlayers and thickness of concrete toppings on improving the impact sound insulation performance was investigated experimentally according to ASTM standards in this study. The results showed that with the same elastic layer, thicker concrete toppings resulted in better impact sound insulation performance with a higher apparent impact insulation class (AIIC). However, by increasing the concrete thickness from 38 to 50 mm and to 70 mm, the improvement of AIIC between two thicknesses was only within 3, and a significant improvement up to 9 was observed with a 100-mm-thick concrete topping. In general, elastic interlayers with lower dynamic stiffness values performed better; however, the performance was product dependent though the apparent dynamic stiffness was measured using the same standard method. Moreover, with the same panel thickness and wood species, a bare DLT floor provided higher AIIC (35) than a bare CLT (21), but each mass timber floor with the same interlayer and floating concrete topping had the same impact sound attenuation performance. The ISO empirical prediction equation overestimated the impact sound attenuation of floating concrete toppings on mass timber floors.

Abstract

Scissor structures, widely used in kinetic architecture, have been researched for over six decades. However, most studies focus on the deployability of the scissor structures, often disregarding the potential transformability of scissor loops that allow changing the curvature. Three scissor units, namely, translational, polar, and angulated units, do not adhere to the trajectory of an arc suitable for a transformable canopy structure. Although the deployment route of the polar version aligns with this trajectory, it is impractical for achieving transformability due to deviations. Therefore, the paper presents a novel approach to optimize generalized scissor linkages (GSLs), consisting of symmetrical and identical scissor units. Defined by three variables, GSL is introduced to address the transformability issue, and the optimization method is developed. According to this method, the selected polar scissor is modified to synthesize the GSL version. It is demonstrated that no GSL is composed of identical and symmetrical units deploying precisely along the arc trajectory. Nevertheless, the proposed optimization method enables the output GSL to converge toward the desired route. Three basic scissor unit types can be represented by a single parameterized GSL, effectively unifying different scissor linkages under a single definition.

Practical Applications

Scissor linkages find extensive applications in kinetic architecture, such as domes, canopies, tents, emergency bridges, temporary shelters, and responsive facades. Existing studies on such linkages predominantly focus on deployed and contracted configurations of these mechanical structures. This study diverges by attempting to establish intermediate phases for designing such structures that can adapt to changing environmental conditions or user needs. To achieve the objective, the scissor linkage must move within a defined range, conceptualized as an arc of a circle. For instance, by tracking the movement of the sun, one can ensure a consistent positioning of shadowed areas beneath an architectural canopy. None of the existing scissor linkages composed of basic translational, polar, and angulated units in the literature moves along this trajectory precisely. Only polar linkages approximate the desired route despite their large deviations. The generalized scissor linkage (GSL) introduced in the paper with distinct parameters demonstrates fewer deviations. Hence, an attempt is made to synthesize the GSL as the optimized version of the polar linkages. The mathematical foundation of the optimization method is introduced. It is foreseen that this method holds the potential to evolve into a versatile design tool in the future.

Prefabrication is recognized as a key driver for enhancing efficiency in construction projects, encompassing goals related to schedule, cost, quality, and sustainability. Despite the global surge in interest and growth of the modular construction industry, Australia lags behind in the adoption of prefabrication methods. The decision-making process in the construction sector is characterized by subjectivity, dependence on experience and intuition, and a lack of documented decision-support approaches. Additionally, early project decisions are frequently made without a comprehensive understanding of available options and without the direct involvement of relevant parties. This research, following an exhaustive literature review and pilot study, employs a survey distributed among Australian construction experts to gather their perspectives on the decision-making process and preferences concerning traditional and contemporary concrete construction systems. Statistical methods are employed to analyze the collected data, including ranking methods, factor analysis, and ANOVA. The results of the study highlight that schedule control emerges as the most significant factor influencing the choice between in situ and precast concrete in construction projects, emphasizing the importance of adhering to project timelines. Moreover, Australian construction professionals demonstrate a notable preference for precast concrete in diverse building types, a trend supported by factor analysis results indicating a shift toward prioritizing environmental considerations over cost. The comprehensive objectives include highlighting key stakeholders in the decision-making process, identifying preferred precast building types, prioritizing concrete construction systems, and examining potential outcome variations across the public and private sectors, project contractual parties, and Australian states as perceived by construction industry professionals. This study aims to provide valuable insights, specifically targeting the Australian construction industry, with the ultimate goal of improving the informed and structured decision-making process. It seeks to offer decision makers a preliminary feasibility analysis for adopting an optimal level of modularization in construction projects, incorporating expert knowledge accumulated during the early design stage.

Many Tribal Nations are working to build capacity to plan, scope, execute, and operate construction projects internally, yet they face a lack of resources designed to support their efforts to self-perform such projects. In a research study conducted by the authors, 22 professionals in the construction industry were interviewed to identify best practices and strategies for designing and building facilities on tribal lands. This paper presents a construction planning tool borne from these interviews, the Project Definition Rating Index for Tribal Building Projects (PDRI—Tribal Building Projects), which supports planning and executing projects on tribal land considering their unique features. The paper further explores the PDRI—Tribal Building Projects through the lens of the Diné (Navajo) philosophy of Sa’ąh Naagháí Bik’eh Hózhóón (SNBH), and the guiding principles of Nistáhákees (thinking), Nahat’á (planning), Iiná (living), and Sihasin (assurance/reflection). This paper contributes to the architectural engineering and construction planning bodies of knowledge by presenting a new tool to support planning and executing projects on Tribal lands, the PDRI—Tribal Building Projects, and its benefits, including the promotion of culturally responsive communication, ensuring capital projects meet the needs of the tribe, and building capacity for front-end planning in Tribal Nations. The paper also makes explicit connections between the Diné philosophy and the front-end planning process for tribal construction projects.

The cooling energy consumed by HVAC systems is continuously increasing. This can be attributed to climate changes and greater comfort expectations. Technical solutions are required to reduce cooling energy while maintaining the same level of comfort. The application of indirect evaporative cooling (IEC) can significantly decrease the cooling energy demand of existing air handling systems. The feasibility of implementing this method was examined through a real case study. The system’s operation is examined under various heat recovery procedures. Based on the study, the retrofit application of the dry-coil IEC method yields substantial energy benefits. Throughout the study, our goal was to investigate an existing air handling unit (AHU) under actual operational conditions after implementing a direct evaporative cooler and to determine if it leads to a decrease in the demand for mechanical cooling power. This enhancement was attained with minimal adjustments needed in both the control system and technical setup of the AHU. Implementation of the procedure enables a reduction in mechanical cooling peak load, while significantly increasing the useful operating time of the heat recovery and the total obtainable cooling energy. The daily average efficiency of the applicated evaporative cooling was ranged between 72.7% and 72.8%. As a result, the air temperature extracted from the interior decreased by 4.5°C–6.5°C, leading to a boost in the cooling capacity that the heat recovery unit (HRU) can deliver. One of our aims is to draw attention to the importance of moisture transfer within the HRU when conducting energy calculations, as it affects the results. The operational characteristics of the procedure are presented based on results obtained during a torrid day, a hot day, and a summer day.

Abstract

This study explores the major “design issues” raised by the goals, missions, and pedagogical approaches of educational programs and tries to link pedagogical approaches and the architectural design of educational spaces. The scope of this research is the latest Quebec Educational Program (QEP) published in 2005–2007. Donna Duerk’s issue-based architectural programming is used as a research approach to investigate issues and requirements for the design of educational spaces. This approach is a systematic method of inquiry that defines the requirements for a successful project, and it is used to develop a model for the design issues related to the goals, missions, and pedagogical approaches of the QEP for secondary school design in Quebec. The following ten major design issues extracted from the literature review are considered as the basis for the analysis of the QEP: health and comfort, flexibility, technology, efficiency, accessibility, safety and security, pedagogy and space, aesthetics, building condition, and school size. The latest QEP is analyzed to verify which of these design issues are related to the goals and approaches of this program and based on the issue-based programming approach, the final model of design issues related to the QEP is developed.

Practical Applications

New pedagogical approaches replaced the traditional understanding of the transition of knowledge with the viewpoint that knowledge is constructed through active learning and social interactions among students. Therefore, hands-on learning, critical thinking and problem-solving are encouraged as the basics of knowledge acquisition and incorporated into educational programs in many countries. Regarding the significant changes in educational approaches, one of the important challenges for architects is how to translate these requirements into the architectural design of schools. Studies show that the organization of a learning space affects the choice of teaching styles and the prevailing characteristics of the physical design of schools are crucial impediments to reform in educational approaches in schools. This study tries to create a practical approach toward the design of educational spaces to incorporate and translate educational programs into architectural design to support the teaching and learning requirements. Although this study focuses on the QEP, the result of this study can be applied to other educational programs that are based on the same pedagogical approaches.

Abstract

Within the built environment, different types of disciplines, such as architects, civil engineers, and construction (AEC), overlap in professional services. A similar overlap also happens at the university, with architects and civil engineers teaching in construction management-type programs. Academic unit affiliation (i.e., architecture, engineering, or construction management) marks a difference in the requirements for educator terminal degrees, teaching load, and research requirements. Further, there are differences in the discipline-specific coursework (lectures, laboratories, and/or studios) of the different disciplines. These differences may impact educators' perspectives about the online learning environment (OLE). Thus, this paper summarizes the findings of a research project focused on determining how program discipline affiliation differences affect educator perspectives for OLE. A survey methodology was utilized where an online Qualtrics survey was disseminated to AEC educators to determine their concerns about delivering online courses, lectures, design studios, and laboratory-type courses. Since the data collected were qualitative, the framework for analysis of qualitative data for construction and engineering disciplines was used. This research determined that department or program affiliation impacted perceptions of educators and identified a significant difference in perceptions between the two educator groups. This includes differences between educators' concerns and perceptions about which courses cannot be taught online.

Practical Applications

There is a distinct difference in coursework delivery between architecture/architectural engineering/architectural engineering technology disciplines and civil engineering/construction management. As higher education identifies how it will adjust in the future to unforeseen events mandating transitions to online learning, the distinct differences between teaching the closely related disciplines of architectural engineering and civil engineering should be addressed. Recommendations include identifying alternate student engagement for exogenous circumstances that result in school closures. These results further identify differences intrinsic to different engineering faculty based on their accreditation types: ABET-EAC, ABET-ETAC, ABET-ANSAC, ACCE, or other.

Concrete is used as a material in the construction of several types of structures. The structural behavior of concrete is constrained by its lower tensile strength, bending strength, and toughness. Fiber-reinforced concrete is gaining importance in various concrete applications. Research has been carried out to use multiple types of fibers in concrete in different combinations to improve its mechanical characteristics, such as toughness, strength, ductility, and durability. In traditional concrete, microcracks have developed before loading the structure because of volume changes and drying shrinkage. When the load is applied, the microcracks start opening and propagating. Therefore, failure of the concrete member occurs. Hence, the usage of fibers helps arrest the growth of the crack and improves concrete characterization. The goal of this research study is to examine mechanical properties of concrete when used in combination with steel, basalt, and glass fibers. Steel fiber is useful in arresting macrocracks, whereas basalt and glass fibers are effective in preventing microcracks. In this research, the specimens incorporated hybrid (steel, glass, and basalt) fibers in the concrete mix with various percentage proportions at a 0.5% volume fraction. Experiments were carried out to assess the bending strength, compression strength, and splitting tensile strength. Therefore, this research can show comparative analysis for different percentages of fibers to enhance the qualities of concrete and can show the optimum fiber percentage among the proportions selected for this study.

Structural aspects of masonry facade repairs are not always obvious at the project's outset. Stone removal or in situ repairs may cause unintended overstress or instability. Through case studies, this technical note describes our work alongside preservationists, architects, and contractors to provide masonry repairs that address the hidden challenges of structural stability in both permanent and temporary conditions.