Journal of Architectural Engineering

Hydronic heating and cooling systems are among the most common types of heating and cooling systems installed in older existing buildings, especially commercial buildings. According to the 2012 Commercial Building Energy Consumption Survey (CBECS) data set, hydronic heating systems in the United States include two main systems: (i) boilers inside the building represented with a boiler system and (ii) district steam and hot water systems represented with district heating, which are connected to seven different types of zone-level equipment. Similarly, there are two main hydronic cooling systems: central chillers inside (or adjacent to) the building and district chilled water piped in from outside the building. Chiller systems are investigated based on three different classes: (1) water-cooled, (2) air-cooled, and (3) absorption chillers. This study presents a deep analysis of the 2012 CBECS microdata to characterize hydronic heating and cooling systems by year of construction, census division, building area, building site hydronic system energy use index (EUI), and the types of mechanical systems. The results show that nearly 65% of commercial buildings built before 1990 utilize hydronic heating systems. Hydronic heating and cooling system design are a function of a building area. District heating systems are considered as the main heating systems in buildings with an area greater than 18,600 m² (200,000 ft²). In addition, systems with central chillers inside the buildings are responsible for providing cooling for more than 50% of the commercial buildings with areas greater than 9,000 m² (∼100,000 ft²). Among the types of chiller systems, the chiller systems connected to the central air handling units, fan coil units, and duct reheats are the most common systems for large buildings. The results of this building stock characterization provide useful insights into the characteristics of hydronic heating and cooling systems in US commercial buildings.

This paper investigates the impact of revised seismic hazard values in the National Building Code of Canada (NBCC 2015) on the design of reinforced-concrete (RC) shear wall buildings. Five buildings with different heights located in three cities in Canada are selected. Toronto, Montreal, and Vancouver are selected to represent low, medium, and high seismic hazard zones. The buildings are designed according to the NBCC 2010 and then checked against the updated design spectral accelerations of the NBCC 2015. The seismic demands are compared, and the need for retrofit of existing walls is evaluated. The analyses showed that the maximum interstory drift ratios increased specially for buildings in Vancouver. The shear force and bending moment demands increased for most buildings in Vancouver by up to 32% and 60%, respectively. A significant decline in the moment overstrength ratio was noticed for walls in Vancouver, which indicates that flexural strengthening might be mandatory for these walls. Moreover, the code changes had a great negative impact on the walls’ ductility for buildings in Vancouver due to the higher deformations exhibited. Several retrofit techniques available in the literature were discussed to enhance the flexural strength and ductility of RC shear walls as remedies for the consequences of the updated seismic hazard in Canada.

In cases where the use of a prefabricated housing system is necessary, the lack of a proper decision-making model for selecting an affordable prefabricated housing system can lead to the selection of an unsuitable system, deviation from project goals, loss of employer capital, and depriving residents comfort. Accordingly, this study aims to propose a decision-making model for the selection of an affordable prefabricated housing system for Iran. The research method of the present article is descriptive-analytic, in which Delphi and the analytic hierarchy process (AHP) are used for data analysis, and the research subjects who filled up questionnaires included 150 experts. Using the Delphi method, 25 important criteria and 5 decision dimensions were identified. Then, using the AHP method, it was found that the decision-making dimension of sustainability (with 7 specific criteria) was the most important and the ecoMOD was the most affordable prefabricated system. According to the results, decision makers in the construction industry in Iran are suggested to consider seven criteria of the sustainability dimension for selecting a system before any other criteria.

Well-designed facilities result in significant social, economic, cultural, and environmental benefits to their stakeholders. In Architecture, Engineering, and Construction (AEC) literature, these benefits are generally referred to as “value in design.” At the same time, it is well known that while value refers to the result of a judgment, values form the basis of it. Further, the existing studies address value in design from the “values shape design” perspective. However, it is also acknowledged that design attributes of built facilities influence the values of its users. The current work is built on the recognition that capturing the relationship between stakeholders' values and design attributes, is essential from the “values shape design” as well as the “design shapes values” perspective. This work explored whether a structured approach could be used to identify the relationship between design attributes and stakeholder values. In this paper, a modified means ends chain framework, called the Stakeholder Values Mapping Framework (SVMF), that utilizes Schwartz’s human values, was formulated. The SVMF was illustrated using the case of a department layout design. The values-design attributes relationship for three categories of stakeholders were mapped using the framework. The outcomes of the SVMF implementation were in the form of hierarchical value maps (HVMs). The analysis of the HVMs revealed how building design components such as the “courtyard” and abstract attributes such as the “configuration of spaces” aided in addressing a variety of stakeholder values. Further, the SVMF was able to map the relationship between the spatial aspects of a design and the stakeholder values. The analysis of HVMs further showed evidence regarding the influence of design on the values of the users of a facility.

Low-frequency noise control in buildings is a critical issue because of the weak sound insulation in low frequencies (<200 Hz) for doors and partitions. In the present study, an analytical model has been proposed to specify the relationship between the acoustic parameters, such as acoustic impedance, of honeycomb, and the honeycomb geometry has been investigated to vary the resonance frequency of the honeycomb structures and increase the amount of sound absorption coefficient. In this regard, three materials (polycarbonate, polypropylene, and polyurethane), seven angels (45°, 30°, 15°, 0°, −15°, −30°, −45°), and two cell arrangement (1 × 3 and 2 × 6 state) were considered to discern the effect of these parameters on the sound absorption coefficient. Sound absorption in the frequency range of 1 to 500 Hz for angles of 45°, 30°, 15°, 0°, −15°, −30°, and −45° were demonstrated using MATLAB software. A comparison of the results shows that the greatest absolute value of the angle is caused by the highest sound absorption coefficient. By comparing the absorption coefficient values of all three materials, it can be concluded that the 1 × 3 state has higher absorption than the 2 × 6 state; also, the number of resonance peaks of polyurethane material for all angles is greater than the other two materials in the same frequency range. Then, in the first loading type orientation, for having more sound absorption, the panel with the honeycomb core of polyurethane and 1 × 3 state is recommended for cells with an internal angle of −45° in the case study of the present research.

The purpose of this paper is to address the importance of project management education and building information modeling (BIM) for coordinating mechanical, electrical, and plumbing (MEP) services. Coordination of MEP services for large projects is often complex and challenging. A systematic literature review was carried out to understand the previous research on the coordination of MEP services for various building projects. This paper proposes a unique framework to simplify the process of learning MEP. The framework recommends covering MEP education in three stages: fundamentals of project management, fundamentals of MEP services, and use of BIM for MEP. The paper discusses the importance of learning project management and BIM for reducing the complexity of MEP coordination. The author cites his own teaching experiences and examples to justify the proposed framework. The finding of this study provides significant insights for practicing architects and engineers working in the domain of MEP services and will help them to understand this complex and exhaustive topic in a more simplified way. The study offers an interesting perspective of integrating the fundamentals of project management and BIM for MEP education.

Consisting of linear elements, reciprocal frame structures are three-dimensional (3D) self-supported structures that can be rapidly assembled. This feature renders them suitable for both temporary and permanent uses. Considered as a type of deployable frame, such structures can be used in architectural and engineering applications. As a subset of reciprocal frame structures, rotegrity structures can be advantageous, owing to their structural form. In this work, a spherical rotegrity structure is constructed on a geodesic sphere through its transformation to a reciprocal structure with mutually supporting elements. Instead of the bolted connections commonly used in practice, a notched connection is proposed to facilitate the construction process of the self-supporting rotegrity structure. The parametric modeling of the rotegrity structure is created in Grasshopper, and two prototypes, having circular and rectangular cross sections, are built. In each prototype, two sets of elements, called Type A and Type B, are used, the linear member lengths and cross sections of which are identical. The cross sections of the members of the two prototypes are different. To assemble the prototypes, first, a number of elements are fabricated through 3D printing and tested in terms of their self-supporting capabilities and connections. Then, stainless steel pipes and wooden bars are used for Prototypes I and II, respectively. It is found that Prototype I, composed of circular hollow section profiles, is unstable, owing to the rotation of elements and because it requires the use of stabilizers. Conversely, Prototype II, which consists of rectangular cross-section elements, becomes stable when the last element is installed in the right place and did not require any additional attachment.

This work presents a field investigation and numerical simulation for studying the heat transmission through the walls of two specially designed test rooms exposed to the hot and arid summer climate of the coastal region of eastern Saudi Arabia. The walls of the reference room were constructed of typical hollow-core concrete blocks, while the walls of the second room were made of concrete blocks incorporating expanded polystyrene (EPS) panels. Both test rooms were equipped with thermocouples, heat flux meters, temperature/relative humidity sensors, and power meters that provided continuous measurements during the test period. Infrared scanning and U-value measurements were also performed, and a weather station installed at the site provided the meteorological data. The results of these measurements revealed that the walls made of the concrete blocks incorporating EPS panels have a heat flow resistance about 255% higher than that of the walls built of typical hollow-core concrete blocks. Similarly, the thermal transmittance was lower by about 65%. Accordingly, the second room displayed a reduction of 29% in energy consumption for providing the same level of thermal comfort during the summer months as compared with that in the reference room. Both test rooms were simulated using DesignBuilder software, and the simulation results were validated with the field monitoring data. In addition, parametric studies were subsequently carried out to evaluate the effectiveness of other insulation materials. It was found that the application of the reflective coating and insulating plaster over EPS concrete blocks could further improve the reduction of energy consumption to about 47%.

The interventions of decision support tools and techniques are necessary for making decisions on complex issues that involve numerous parameters. In the construction industry, the identified barriers that affect the implementation of decision support tools revolve around the issues of scarce information, diverse project characteristics, bureaucracy, and low precision of statistical decision models. This study aimed to design a decision support tool for the assessment of the suitability of a design-build method (hereafter DST-DB), which can efficiently assist practitioners in the adoption (or rejection) of the design-build method with greater convenience. The selection factors were identified by compiling and validating key design-build selection factors of critical success factors (CSFs) and design-build-drivers (DBDs) through an extensive literature review and consulting with industry experts, resulting in the development of DST-DB. The obtained results showed the influence of DST-DB on the practitioners’ perceptions of a design-build method, where DST-DB recorded significantly higher usability, likelihood, precision, confidence, and satisfaction rate than the conventional approach (multicriteria decision analysis) of decision-making in the construction industry. There have been many other decision support studies over the years, but the current study served as one of the first decision support studies for design-build construction projects in the construction industry, which offered appreciative insights into the importance of adopting CSFs and DBDs in decision support tools (DST-DB).

This study concerns the corrosion behavior of a 316L stainless steel railing installed in an aggressive marine–urban atmosphere, located about 400 m as the crow flies from the sea, in Genoa, a coastal city in northwestern Italy. Despite the well-known relevance of surface finishes in determining the degree of resistance to atmospheric corrosion, the initial surface finish of the material used could not be ascertained. Only 3 months after it was erected, the railing showed, upon visual inspection, reddish-brown halos and spotted deposits distributed diffusely all over the structure. To investigate the likely causes of these sudden and unexpected corrosion phenomena, the morphology of the corrosion and the surface chemical compounds were examined using microscopic (optical and scanning electron, with an electron probe microanalyzer equipped with an energy-dispersive spectrometer) and profilometry (no-contact three-dimensional optical profiling) techniques. The morphology of the steel surface finish on the specific material used for the structure was found to be unsuitable for its designated use in such an aggressive atmosphere. Chloride occurring along the constituent grain boundaries of the rough surface finish triggered intergranular corrosion, leading to grain fall out and subsequent significant localized corrosion.

Practical Applications

Stainless steel is one of a group of ferrous alloys that contain chromium in order to prevent the iron from rusting. Different types of stainless steel are characterized by different percentages of chromium, which mainly determines their resistance to corrosion and their price. The resistance to corrosion and staining, low maintenance and ease of cleaning, and pleasant aesthetics make stainless steel a material widely used in diverse building and architectural applications. Besides the chemical composition, the surface finish of stainless steel is a key factor in determining the durability and appearance of structures. The key message of this work is to alert building engineers to pay careful attention to the choice among not only different stainless steels, but also, and mainly, the different surface finishes. An inappropriate or incorrectly surfaced finish, even on a high-grade stainless steel, can rapidly impair the corrosion resistance of the steel structure, as exemplified in this case of an aggressive maritime coastal environment.

The demands for sustainable designs in the building industry have increased dramatically and the industry needs to adapt to these demands. As sustainability has become a natural part of building projects, the need for methodologies and quantifiable measures has increased. This paper investigates possible strategies for benchmarking sustainability performance in project-based organizations (PBOs). A literature search combined with action-based research outlines five strategies that could be employed as general-level assessment methodologies. Each strategy is tested within an archetypical PBO in the Danish building industry. Six criteria are identified for performing a structured evaluation of each strategy, thereby enabling recommendations for further development. The results demonstrate that questionnaires and simple statistics on the number of sustainability certifications performed possess the most value compared to effort; however, SDG surveys also exhibit potential. The paper concludes that existing methods for assessing impact at an organizational level are in their infancy and must be matured dramatically to match future requirements for the documentation of organizational impact. This paper contributes to the development of efficient future assessment methodologies within PBOs.

In addition to maintaining their cultural, social, and economic character, repurposing old industrial edifices breathes new life into them. The historical Khosravi leather factory was built in 1931 in the city of Tabriz in northwestern Iran. After restoration and repairing, the building has served as the main campus of the Tabriz Islamic Art University. The materials used in the construction of the building (i.e., unreinforced masonry) and the location of Tabriz is one of the most seismically active regions of Iran are the two main factors necessitating the strengthening of the faculty of design of the university. This study, therefore, aims to investigate the efficiency of a seismic retrofitting scheme proposed for the rehabilitation of this building. In the first step, the structure was quantitatively evaluated to determine its current structural condition. Then, by setting an optimal improvement goal, nonlinear static analyses were employed to assess the building’s structural response. The results of the analyses indicated that the building was incapable of reaching the Life Safety performance level, and the majority of the perimeter walls were ill equipped to withstand lateral loads. Therefore, it was vital to retrofit the structure using an appropriate retrofitting technique. Reinforced concrete (RC) shear walls seemed to be a suitable approach and thus were used to retrofit the building. A brick jack arching floor separated the first-floor story from the second floor, which itself had a wooden truss structure as its roof. These were strengthened using, respectively, concrete slabs and horizontal braces. The studied structure was devoid of any horizontal and vertical confinements, which is why several confining elements were used to enclose the masonry walls. The results obtained from the pushover analysis show that the desired rehabilitation goal was met and that the retrofitted structure has an acceptable performance.