Journal of Architectural Engineering

The Temple of Sagrada Familia presents singularities in terms of both the original design by architect Antoni Gaudí and the duration of the construction, which started more than 120 years ago. In fact, its design was conceived before the development of reinforced concrete. Therefore, the construction materials and processes have evolved to adapt new technologies without compromising the vision of Gaudí. This willingness to maintain the original designs has obliged the technicians to resolve details that were not defined in the project, including the issue of how to cast elements at great heights and with a high amount of reinforcement. In this context, the possibility of using self-compacting concrete (SCC) emerged. This paper describes the different experiences in the Temple of Sagrada Familia with SCC, from requirements that led to using this material to the design of the mixes and the casting of the elements in situ.

An airport is a building type that exemplifies the wide range of interactions that can occur between building occupants and their surrounding luminous environment. Research has found numerous health and productivity benefits associated with daylight for building occupants. However, designing effective and efficient daylighting solutions is a complex task that involves balancing various dynamic factors and personal and task-dependent preferences. This paper explores the ways in which different occupant types have different visual requirements and relationships to the luminous environments as illustrated by airports, a building type that has unique and challenging daylighting conditions because of widely varied occupant types and peak hours of operation aligning with low (early-morning and late-afternoon) sun angles. The contribution of this research is the synthesis of examples from professional analyses of airport daylighting design that serve to highlight potential benefits and challenges associated with the complex interactions of occupants with daylight in airports and other places. Findings suggest that trades-off frequently occur within the luminous environment of airports across the wide assortment of occupant types. Findings also suggest that such challenges can affect the energy efficiency in the large and varied spaces of airports.

On January 3, 2011, the City of Boulder, Colorado, implemented the SmartRegs ordinances and, in doing so, became the first city in the nation to require energy retrofits for rental properties; 20,000 rental units comprise nearly 50% of Boulder’s total housing stock, and the mandate requires that all rental properties meet the minimum energy standard by 2019. The objective of this research is to explore prescriptive and performance pathways and tools used to comply with SmartRegs. The primary contribution is to illustrate and assess the SmartRegs compliance process rather than to generate or validate precise performance results. The research first uses building optimization software to perform secondary analysis of three previously conducted audits to explore SmartRegs compliance pathways. Next, the research uses a case study consisting of a stand-alone residential rental unit in Boulder to compare prescriptive-based and performance-based SmartRegs upgrade recommendations. Findings highlight the challenges, opportunities, and nuances of implementing such an ordinance. Specifically, special considerations regarding the property’s circumstances may play a large role.

Hurricane resilience has been identified as an effective metric for the risk assessment of residential communities. The potential effects of a changing climate and environmental impact could severely aggravate the monetary losses of a residential community caused by hurricane events. An existing framework was used to evaluate hurricane resilience of a residential community, which includes hurricane fragility, reliability (e.g., annual probability of failure), loss, and recovery time analyses. However, the existing framework could overestimate hurricane resilience by not considering the potential effects of a changing climate or social disruption and environmental costs. The aim of this paper was to improve the existing framework and investigate the sensitivity of hurricane resilience of communities by including three key components: a changing climate, a social disruption cost, and an environmental cost. Hurricane simulation models in the framework include both stationary and nonstationary wind scenarios. The improved framework can be used by stakeholders to achieve the performance goal of hurricane resilience of a residential community.

In the Canadian building sector, residential housing has been identified as the largest contributor to greenhouse gas (GHG) emissions. Similarly, high-income countries, such as Saudi Arabia, are also excessively investing to meet their residential demands. Although developed countries are considered to have more sustainable development practices, factors such as occupancy per household and floor area of a single-family residence can contribute to greater energy consumption and GHG emissions per capita. To develop global sustainable strategies, there is a need to evaluate the global warming potential (GWP) on a household basis by considering different lifestyles and climatic conditions in different parts of the world. In this study, a methodical framework was developed to compare an average Canadian single-family detached house (CSDH) with an average Saudi Arabian villa (SAV) (with similar living standards) based on their energy consumption and associated GWP. Demographic and environmental data were collected from the literature and relevant organizations. To accommodate regional variations in construction practices and climatic conditions, two different types of houses in five different cities of both the countries were analyzed. The study found that the overall GWP of a SAV is approximately 25% higher than that of a CSDH because of the larger floor area. However, comparison on a per-person (occupant) basis revealed that the SAV produces 43% less GHG emissions than the CSDH. The results of this study will assist in formulating sustainable development policies in the residential sector and provides a rationale for both Canada and Saudi Arabia to adopt sustainable development strategies.

The observation that spandrel glass with ceramic frit has experienced thermal breakage in several buildings has called into question the ability of heat-treated (HT) glass with ceramic frit to resist fracture induced by lateral loads. The authors note that the use of ceramic frit is not restricted to interior lites of spandrel insulating glass. Currently, glass design standards in the United States do not specifically address any impact ceramic frit might have on the load resistance (LR) of HT glass, while European standards impose a reduction on allowable stress in HT glass with ceramic frit. This article presents the results from the first phase of a research program aimed at determining the reduction in LR that ensues from the application of a ceramic frit to HT glass. The results of this research indicate that ceramic frit significantly weakens HT glass to which it is applied.

Tensegrity, as a typology of designing structural forms, can be applied in the construction industry. As a structural system, it can produce a number of forms. Nonetheless, the particularly complex geometric forms that can be generated through the use of this typology constitute a significant hurdle to engineers, architects, and designers who need to produce two- or three-dimensional models. A sequential mathematical process was developed so that, in a systematic way, a user can apply this method as a step-by-step flowchart to design a structural form. This series of steps can ideally be applied in an algorithm or a computer program that can ultimately produce virtual three-dimensional models of these structures to enable the user to make decisions and adjust the geometric forms to the needs of a project. The objective of this study was, initially, to produce these mathematical relations and, ultimately, to formulate a series of variations in the methodology of design. Sequential processes will make it feasible to produce the specific forms of a spherical dome, cylindrical vault, or flat plate according to the project’s priorities. Variations of the sequence will be applicable according to the methodology of the design to be followed. The selected processes assist the initial generation and parametric modification of the numerical data that lead to unobtrusive regeneration of alternative solutions with the possibility of fine adjustments on each iteration. Validation of the process was performed through a series of tests on all three formations, and an example is briefly presented in this paper.

Stick-frame residential construction is renowned for being leaky. Structural insulated panels (SIPs) theoretically resolve the issues with air and thermal leakage, but such construction systems are new to the Australian housing market. The purpose of this study was to determine the extent to which a steel-skinned SIP construction product could resolve air leakage and thermal performance challenges in five climate zones across Australia in 2015. All houses used the same steel SIPs as the main construction element (walls and roof). Airtightness and thermography tests were conducted in each house in winter to identify air and thermal leakage paths. The results show that even first-time users of this product can produce well-sealed homes, but there is a need to address thermal bridging (because of the steel componentry) and to consider the house as a whole system (not just walls and roof). The results of the study raise questions about thermography test procedures and airtightness regulations for naturally ventilated homes in warm-temperature climates. Addressing these issues will assist in the diffusion of innovative construction products and methods to enhance the energy efficiency of housing.

Several of the fortifications built in the Crown of Castile during the Late Middle Ages (14th–15th centuries) used the technique of rammed earth. Five rammed-earth buildings are analyzed in the article as examples. Several of them have been erroneously dated as Islamic, despite their late construction. They were built with lime-crusted rammed earth in which the putlog holes are passant. To permit the reuse of the putlog beams, the hole is formed by a lintel of stones placed over the putlogs to allow their extraction; this is one of the differences between the Christian and Islamic Medieval Spanish rammed-earth techniques. The study of the techniques is fundamental, by establishing chronological and constructive types, to propose an approximate date when there are no architectural, aesthetic, or documented criteria that yield this information.

Understanding temperature and airflow patterns in an attic roof helps to identify the sections of the roof where moisture damage and roofing material durability problems can be expected. In this paper, the temperature distribution and the airflow patterns inside an attic space in a climate that can be characterized with cold winter and hot summer periods are discussed. In the study, transient boundary conditions were applied, and the dynamic responses of a typical attic roof, including the flow patterns, attic air and roof sheathing temperatures, ventilation rates, and heating and cooling loads, are presented. These findings can be used to understand the airflow pattern and how it can be affected by an incoming wind speed and solar gain.

With more than 14.9% of the current population being elderly, an aging society is a challenge for China. To accommodate the rapid increase in the aging population, it is necessary to provide sufficient and satisfactory homes for the aged. However, currently, China’s homes for the aged are different in terms of capacity, building size, built environment, and facilities. Using a postoccupancy evaluation method, this study aimed to compare the elderly residents’ level of satisfaction with the built environment in homes for the aged. To achieve this, both individual surveys and site visits were conducted with residents in 15 homes for the aged. A total of 284 questionnaires were completed by elderly residents living in homes for the aged. The results indicated that there were significant differences among the levels of satisfaction with the built environment in different homes for the aged. Based on detailed investigations of the built environment in the 15 homes for the aged, a number of recommendations are made to enhance the satisfaction of residents, including financial support for the built environment within homes for the aged, review of current building requirements for elderly living spaces (e.g., over 30 m² for one to three persons per room, 4 m² for toilet/bathroom, 1.5-m-wide corridor, and at least 100 m² of outdoor green space), installation of air conditioning and heaters for a stable temperature, weekly changes in catering menus, and so forth.

This paper treats the interaction of outrigger-belt systems (OBS) with structural frames in high-rise buildings with composite columns caused by differential axial shortening (DAS). The presence of OBS significantly reduces DAS in composite buildings, but when used without belts, the DAS problem is aggravated. Current methods using results from elastic single-step or staged construction reduce the accuracy of DAS predictions and result in either unsafe or overconservative designs of OBS. For modern complex buildings, the comprehensive method used in this paper, which incorporates all the influencing factors including the outrigger-belt and frame interactions, provide more accurate results. Findings from the present study show that locations of OBS influence DAS considerably and can be used for minimizing DAS. Delayed connection of outrigger walls to perimeter columns can mitigate the adverse effects of DAS, with a delay of 1–2 weeks resulting in significant reductions in stresses developed because of DAS. Information generated in this paper will be useful for planning suitable methods for OBS analysis and to minimize adverse effects of DAS in composite high-rise buildings.

Low delta T syndrome, that is, the operation at low differences between supply and return chilled-water temperatures, increases the energy consumption of chilled-water systems. Numerous causes of low delta T lie at the cooling coils. As the load on the coil increases, more chilled water is sent through it. A point of saturation is reached when significant increases in chilled-water flow result in negligible increases in provided cooling power. The ability to recognize when such saturation is occurring and restrict flow in such situations is needed to combat low delta T. An intelligent pressure independent control valve attempts this by measuring and logging inlet and outlet water temperatures and water flow rates. Through nonlinear regression of measured coil data, a novel approach for the valve to predict saturation was developed and tested. The resulting curve fit was then used to predict whether a coil was operating in a constant- or variable-air-volume system. In total, 128 test coils over four climates and various system characteristics showed a 79.7% correct prediction rate.

Falls from roofs in residential construction can cause catastrophic injuries with severe consequences. Ensuring that personal fall-arrest system anchors are attached securely to the building with a clearly defined load path is important. In this article, the authors measured the load capacity of a series of five metal plate–connected wood trusses in a roof system using various top chord bracing elements and different fall-arrest anchors. The different types of top chord bracing included wood bracing installed between the joists, wood bracing installed on top of the joists, and a proprietary engineered steel brace. The fall-arrest anchors tested included a stanchion type anchor, a cross-arm strap, and a spreader bar attached to three trusses. Load and displacement of the truss assemblies were monitored continually throughout testing. The in-between bracing performed well because of the compression of the trusses, which created a pinching force on the brace that prevented fastener withdrawal. The three-truss anchor performed well by maintaining the strength of the wood system. The addition of sway bracing and additional top chord bracing located near the cross-arm strap created an anchor strong enough to meet Occupational Safety and Health Administration (OSHA) regulations. Sway bracing is recommended as an effective way to tie the truss structure together because it creates a greater distribution of load through the truss members. Proper bracing of the structure is essential for providing adequate support to fall-arrest anchors.

The intimate relationship between energy consumption and climate change demands attention. More energy will be needed to run cooling systems if the annual global temperature continues to rise. The urban heat island would also increase the demand for cooling. As global energy demand continues to grow, the utility sector would face a continuous increase in energy demand. Studies in several countries have shown mostly nonlinear relationships between outside ambient temperature and electricity consumption, whereas other studies have suggested the absence of such relationships among high-performance buildings. However, these studies were based on aggregate data from entire cities and/or countries (indirect relationships) and were not based on real-time data (direct relationships). This study uses continuous real-time data from four high-performance research buildings and presents the results from a set of correlations and regression analyses between several variables, i.e., outside temperature, heat index, electricity consumption, and the production of solar energy. The authors found no relationship between electricity use and outdoor temperature, and between electricity use and heat index. Conversely, the efficiency of the production of solar energy was affected negatively by higher outdoor temperatures.

As the importance of sustainable design continues to grow, it becomes increasingly vital to develop methodologies capable of aiding designers in assessing if a project is sustainable and cost-effective while still in successful parallel with the owner’s goals. This paper proposes a model to optimize the selection of a design alternative given a project’s conflicting objectives: net-zero, Leadership in Energy and Environmental Design (LEED), and cost. The proposed model combines both the analytical hierarchy process (AHP) and multiple attribute utility theory (MAUT) in such a manner that a decision maker can specify a project’s objectives and use weights to prioritize certain goals. This paper presents a case study analysis using two building projects as an implementation platform for the model’s methodology. Using inputs from two case study projects, the model is used to determine the best alternative given the three main conflicting objectives. The paper concludes with a discussion on the validity of the model and its contribution to the practice of sustainable building design.

Healthcare facility retrofit projects are among the most challenging types of construction. Such projects are often disruptive to patients and can cause significant patient safety issues. The aim of this study was to investigate current practices of retrofitting healthcare facilities, with a particular focus on patient safety and energy efficiency. To achieve this, the study followed a systematic approach to investigating the issues involved with retrofitting healthcare facilities. Three case studies were conducted, and data were collected through interviews, shadowing, site visits, and cognitive walkthroughs. Direct observation of retrofit projects was also undertaken to acquire firsthand knowledge of the retrofit process and to explore possible solutions associated with current practices. As more facilities consider the decision to retrofit, it is essential to provide a practical rationale for pursuing retrofit projects that are energy efficient and safe for patients.

The housing market is urgently demanding customized quality buildings at affordable costs. Housing prefabrication represents a suitable strategy as long as it is combined with cost-effective personalization through mass customization. Designs need to be easily customizable to foster the mass customization of prefabricated housing. Decisive requirements are design robustness and flexibility. Crucial decisions for the achievement of these requirements are made in the conceptual design phase, but this stage is not adequately supported, and tools for addressing decisions during this phase are not provided. In engineering design, axiomatic design (AD) has been shown to be able to support the analysis of existing ideas in terms of aptitude for customization and the generation of robust and flexible solutions that are easier to customize. Thus, the current study applied AD to the analysis of well-known prefabricated houses and the design development of a new prefabricated housing system to show the potential benefits of this approach for the building industry. Results show that AD has the ability to support the analysis of ideas for identifying problems linked with customization and the ability to address the conceptual development of robust and flexible designs for providing easily customizable solutions.

The construction plan of a structure should not be developed in isolation—that is, without considering the structure’s surroundings. It is affected by or has an impact on existing facilities/utilities in the structure’s immediate and broader surroundings. The computer-aided design (CAD)–based planning tools used in the construction industry primarily consider the geometry of a structure to be developed. The effects of surroundings and existing facilities/utilities on a construction plan are considered manually by planners based on their judgments and past experience. The CAD-based planning tools help planners in developing an execution schedule, cost estimate, and four-dimensional (4D) simulation but lack in considering surroundings that include topography, spatial constraints, and elevation. Geographic information systems (GIS) are generally used to consider surroundings and existing facilities/utilities and to carry out various geospatial analyses; hence, an interactive and collaborative framework integrating CAD and GIS was developed in the present study. The major contribution includes the development of an integrated framework for the 4D modeling of an execution sequence along with its surroundings to support construction planning. The integrated framework brought multidisciplinary areas together to create an executable construction plan. The developed framework was used in the construction planning of a building constructed at the National Institute of Technology (NIT) in Hamirpur, India. The construction plan was finalized by keeping in view the spatial constraints and dependence of the proposed structure on the existing facilities/utilities.

This experimental and numerical study investigates the thermal behavior of an attached garage before, during, and after a vehicle is parked within it. Although the characteristics of most indoor spaces are understood and incorporated into modern heating, ventilating, and air-conditioning load and energy programs, as well as in older hand calculations, the transient heat transfer between a recently parked vehicle and its garage, the outdoors, and any attached conditioned spaces has not been incorporated. This paper presents, through an experimental and computational study of an actual garage and vehicle (both common types for North America but explained in detail for those readers not familiar with them), how the garage, vehicle, and house interact. The time-varying heat gain rate from the vehicle is found along with the heat gain to the various surfaces in the garage and to the attached conditioned space. Although finding the heat loss rate from the vehicle and heat gain rate to the conditioned interior were the goals of this research, an unexpectedly large heat transfer path for the vehicle’s heat was found. This study’s results were intended for garages attached to residences, but its observations may be extended, with care, to enclosed garages for larger buildings and those that are freestanding.

Cross-laminated timber (CLT) is an engineered wood material that was introduced in the last decade as a promising candidate for building wood structures higher than 10 stories. Thus far, a handful of tall residential CLT buildings have been built in low seismic regions around the world. Previous full-scale seismic shaking table tests of multistory CLT buildings revealed that this system is susceptible to overturning damage as a result of lateral seismic loads. To effectively resist overturning, a new floor connection detail was proposed to engage CLT floor panels as coupling elements for CLT shearwall stacks in the building floor plan. This approach is fundamentally different from traditional isolated shearwall stack design methods used in multistory light-framed wood buildings. The proposed method was illustrated through the seismic design of a 12-story CLT building located in Los Angeles, California, which was then subjected to the design equivalent lateral force to evaluate the conservativeness in the proposed simplified calculation.

Cross-laminated timber (CLT) has emerged in recent years to become a widely recognized mass timber product for large-scale wood construction projects. The advantage of large CLT buildings has been recognized by investors and the public, resulting in a number of tall wood buildings around the world. It is generally believed that newly constructed CLT buildings can be cost competitive against steel and concrete options in certain scenarios. However, the cost-effectiveness of CLT in single-family residential construction is questionable compared to traditional light-framed wood construction. In this study, a comparative construction-cost study was conducted for three different designs using the same single-family residential floor plan: traditional light-framed wood, all CLT, and optimized CLT options. The cost differences among these different options were quantified, and the potential of CLT single-family construction was evaluated in terms of construction cost.

Structural glass is being used in increasingly challenging applications by engineers and architects; however, there is currently no universally adopted analytical method for the design of monolithic slender glass elements subject to lateral-torsional buckling. As a result, designers must use guidance from several different sources. In this study, a number of prevalent standards and design guides was examined and design calculations undertaken using the methods proposed. The design results were compared to experimental data from the literature to assess the level of conservatism in each method. A noticeable difference was observed among the investigated approaches with some potentially unsafe estimations of design buckling capacity. Local tensile stresses were investigated, as was global buckling behavior, because these are important considerations when designing brittle glass elements. Finally, a parametric study was undertaken to assess the influence of key variables on the design solutions.