Journal of Architectural Engineering

The building sector is one of the most resource-exhausting areas in global energy consumption. Maintaining good thermal comfort for occupants is the leading energy demand in buildings. The primary purpose of the current study is to identify the development of research areas on occupant comfort, pinpoint the gaps in knowledge and recommend directions for future studies. A scientometric analysis and a comprehensive systematic literature review are conducted using 792 sources. It is evident from the exponential increase in published papers that scholars are highly interested in this research topic. However, discrepancies remain between the two fundamental models of evaluating thermal comfort. There is a pressing need to balance thermal comfort while increasing energy efficiency. The foundation of achieving this balance can only be done by correctly evaluating the surrounding environment of occupants and understanding all the factors influencing human thermal comfort conditions. There is also a high potential in employing industry 4.0 technologies to assist in designing more innovative solutions for thermal comfort. Furthermore, there is a need for local thermal standards targeting specific regions. The lack of interoperability between 3D building information modeling (BIM) and energy simulation tools remains an obstacle.

Vertical protruding elements are popularly used for building aesthetics, solar shading, and reduction of energy demand. However, no sufficient design guidelines are available yet for wind loading on curtain walls, especially those with vertical protrusions. In addition, water intrusion tests carried out by curtain wall manufacturers use static or pseudo-dynamic wind loads according to available testing manuals which are not realistic to simulate extreme wind and wind-driven rain conditions. This study investigates the influence of vertical protruding elements on the overall wind actions on a single skin façade using full-scale testing. The results show that vertical protrusions can increase the pressure around the protrusions and the wall (as evidenced by increased pressure coefficients) by as much as 30% and 19%, respectively. Furthermore, the vertical protrusions used in this study increased the overall stiffness of the curtain wall system, which led to an increase in the vibration of the glass units. Wind-driven rainwater intrusion tests on a façade unit without vertical protrusions indicate an increase in water penetration with wind speed at vulnerable joints (i.e., joints with windows) and less than 5 mL at the non-vulnerable joint at all wind speeds tested.

Abstract

The temperature increase in cities called the “urban heat island” (UHI) depends on the local microclimate (e.g., solar irradiation, population, buildings density, industrial activities, traffic, emissions, heat sources) and results not only in increased electricity consumption for indoor cooling but also in decreased outdoor comfort, especially in summer periods or in warm climate zones. As the world’s urban population continues to grow, there is an urgency to make buildings more ecoefficient and reduce the impact of cities on climate change and global warming. In this framework, the use of cool concretes can mitigate the UHI and improve energy saving and outdoor comfort: cool concrete roofs and facade cement-based tiles can provide valid solutions to decrease the energy demand for air conditioning in building envelops; moreover, cool concrete paving blocks and pervious pavements can improve urban comfort for outdoor wellbeing. The present work shows the improved solar reflective performance of three cool cementitious solutions compared with traditional ones, with both white and colored surfaces, to fulfill both architectural demand and sustainability issues without any additional post-treatments or after placing steps, such as surface coating. Finally, the study is completed with the durability evaluation of the products’ solar reflective performance.

Practical Applications

Tackling urban and global warming is one of the most urgent actions to make cities safer and more sustainable as well as to improve citizens wellbeing. From an optical performance perspective, it has been proved that traditional concrete-based materials do play a significant role in contributing to the fight against urban heat island phenomena when functionalized with high-reflective cool materials. Indeed, the near-infrared (NIR)-reflective concrete-based materials, which are the subject of this paper, can participate in mitigating both outdoor pavements and building surfaces temperature, regardless of their color. Lighter or darker concrete surfaces can reflect the sunlight not only in the visible range of the solar spectrum, thanks to lighter nuances, but also in the NIR region, that is, the main area responsible for the surface heating. In addition, we have successfully tested this ability in severe accelerated ageing conditions. The durable—white and colored—concrete tiles here described for building envelopes as well as urban draining or self-locking concrete pavements widen the horizon for more and more sustainable opportunities as well as flexible solutions, matching both modern architecture’s technical and social requirements.

In this study, new steel material classes were added to the OpenSees 3.0.0 library to model their behavior within cold-formed profiles under high temperatures. The new material classes that were added are capable of modeling G-450 and G-550 grade galvanized steels under mechanical and thermal loads. Gypsum panel, a nonstructural material within walls, significantly contributed to the lateral resistance of cold-formed structures. For the first time, the relevant material class was added to OpenSees. First, heat transfer analysis was performed to determine the temperature distribution within different parts of the frame structure. Second, the structure was analyzed under gravity loads, followed by thermal loads. Results from the first step were applied to the structure, and a transient thermomechanical analysis was performed. The output of this analysis included the deformation and force of the members of the structure. The behavior of each new material class was compared with the experimental results to determine the accuracy of the developed OpenSees scripts. Moreover, the results related to modeling with this material class were compared with those of the material classes available in OpenSees. The results exhibited high accuracy with the new material class, and the difference in the results obtained with the current material classes in OpenSees was significant.

As awareness around building energy consumption increases, practitioners are encouraged to consider performance aspects regarding the built environment more closely and find ways to improve its efficiency. Improvements in building information modeling (BIM) and building performance simulation (BPS) tools present opportunities to facilitate information communication with a wider range of stakeholders. The building sector can benefit from the integration of performance informatics; however, there has been limited success in utilizing available technologies that promote data integration and management in favor of enriching our knowledge and understanding of buildings as artifacts of information. This phenomenon was investigated by conducting a survey, together with a review of relevant literature, to depict the relevant challenges and opportunities for the architecture, engineering, construction, and owner-operated (AECO) industry, as it undergoes digital transformation, as well as the working practices that have formed around them. It is argued that the current tools available to practitioners do not support effective data serialization between design and analytics processes, affecting the collaboration between team members. Finally, a series of functional goals are proposed to support a higher level of reliability in the ways information is mobilized, by rethinking the technologies and methods for organizing information systems.

As of 2020, an estimated 20% of energy was consumed by the residential sector. Different factors influence the energy usage of residential buildings. There are a significant number of studies to understand the implications of such factors on the energy consumption of domestic buildings. However, existing studies do not explicitly demonstrate the importance or connection between the variables. The objectives of this study are to determine the effectiveness of parameters that influence energy usage in residential concrete structures and to develop a priority weight-based system to determine energy consumption levels in residential buildings in developing tropical countries like Sri Lanka. In this study, the fuzzy analytical hierarchy process is utilized to develop the system by generating priority weights that account for parameter interrelationships and relevance. The novel identification system is developed considering four major parameters: building characteristics, characteristics of appliances and systems, characteristics of tenants’ behavior, and climatic characteristics. These major factors are further divided into subcategories. The priority weights of parameters are calculated based on the input of 100 experts. The subjectivity of the developed system is eliminated by using numerical descriptors. The proposed model can predict energy consumption levels in residential buildings and identify the influence of factors affecting energy consumption. Understanding and modifying home energy consumption behaviors are effective in promoting energy efficiency and energy conservation.

Off-site construction (OSC) methods have captured significant recognition during the last decade due to a range of benefits offered, from reduced construction time and cost to improved efficiency and environmental savings. OSC is proven to have enhanced performance in environmental issues such as waste generation and carbon emissions. However, even with well-documented benefits, by 2018, no major market has yet exceeded 20% of OSC penetration. Thus, identifying factors that advanced and enhanced the environmental performance of OSC from current research to understand the learnings and strategies is timely. A systematic literature review on the role of developed and developing economies in the environmental sustainability of off-site constructed buildings and identifying critical success factors (CSFs) is a novel research opportunity in the current literature. Thus, this research presents a systematic review of the environmental sustainability of OSC (ESOSC) with a clear focus on comparing OSC and its advancements in developed and developing countries. The research methodology involves a bibliometric analysis (BA) followed by an in-depth qualitative discussion. The BA identified key research trends, gaps, and governing countries in ESOSC research. The critical review has significantly focused on comparing the ESOSC studies in developed and developing countries to understand the differences, similarities, CSFs, and future opportunities. The outcomes of BA and critical discussion suggested that further research is required in the following topic areas: comprehensive sustainability assessments, smart/computerized technology integration, prefabrication rate-related research, integration of circular economy/sustainable development goals, and developing region-specific research. The theoretical value of the paper is in facilitating a solid basis for future investigations into the role of these economies in the triple bottom line of sustainability. The practical contribution of the study is to guide OSC stakeholders to increase the rate of OSC adoption and boost environmental performance.

During the last decades, virtual reality (VR) has been devoted to supporting research in the architecture, engineering, and construction sectors because of its ability to provide multisensory three-dimensional (3D) environments. However, the use of immersive virtual environments (IVEs) in the design of the built environment is still in its infancy, and it is limited to visually designed spaces. In addition, a fundamental challenge lies in improving the sense of hearing. The effective simulation of the built environment with an overall realistic perception will support designers when identifying the influence of design decisions and building acoustics on individuals, therefore, properly designing acoustic strategies. In this study, five disrupting sound sources were selected to create a binaural soundtrack that was integrated within a virtual office environment to evaluate the effectiveness of the model (i.e., ecological validity) and the effects of acoustics on user comfort and cognitive performance (i.e., criterion validity). Independent measure design research was employed. In total, 104 participants performed working memory, inhibition, and task-switching tests under quiet (Q) or noise (N) conditions when the indoor air temperature remained constant. The results showed that the modeled virtual office created an excellent level of presence and immersivity with no significant cybersickness disorders (i.e., ecological validity). Ambient noise disrupted work efficiency with a relevant decrease in performance in each cognitive test (i.e., criterion validity). The sound environment was assessed as uncomfortable, chaotic, and boring. In addition, it negatively impacted the subjects’ thermal comfort vote (TCV). These results suggested the adequacy of IVE when providing an accurate representation of the variables measured; therefore, it supported effective user-centered design analysis and strategies.

A vertical extension (VE) involves the construction of additional floor space on top of an existing base building. With growing urban populations and an urgency to reduce building-related carbon emissions, VEs might have the potential to be a sustainable and innovative solution to overcome the shortage of urban spaces. However, despite the growing number of projects and the emerging academic literature, limited research has documented the decisions that inform the development of VE projects or the lessons learned from stakeholders that were involved in their creation. This paper presents the early decision-making processes that are undertaken to select a VE as an appropriate development type to construct in practice, and the common challenges and solutions during its realization, through semistructured interviews with a broad range of stakeholders, including developers, contractors, architects, and structural engineers that have been involved in recently completed VE projects. The results identify that the main driver of VEs is economic profit, followed by sustainability goals and the desire to stay on the same site. The challenges are related to the complex design and coordination of VE projects, and onsite construction challenges. In addition, this paper identifies the diverse structural support and reinforcement strategies that are used in VEs and contributes to the knowledge by capturing the different aesthetic and construction approaches that are used in practice.

Abstract

This study aims to explore the key design features that support office building occupants from the adverse effects on health, well-being, and productivity (i.e., the three aspects in the WELL Building Standard). To achieve that aim, the objectives are to (1) identify the key design features that support health, well-being, and productivity; (2) compare the key design features; and (3) analyze the interrelationships between the key design features. Information from a systematic literature review and semistructured interviews with 23 office building occupants was used to develop a questionnaire survey consisting of 33 design features. Mann–Whitney U test, Kruskal–Wallis H test, normalized mean score ranking technique, overlapping analysis, and Spearman’s correlation analysis were used to analyze 206 valid responses. The findings highlighted 11 key design features that simultaneously support office building occupants’ health, well-being, and productivity. The design features are air quality, clean drinking water, comfortable artificial lighting, adjustable workstation, comfortable temperature, sufficient space, security system, safety at parking lots, cleanliness, efficiency in building services, and safe design. From these, the last six key design features are absent from the existing WELL Building Standard. The study findings provide new insights into the body of knowledge on WELL building. Industry practitioners can use the findings in designing, planning, and maintaining office buildings that support health, well-being, and productivity. Additionally, policymakers can establish an alternative rating tool for evaluating office buildings.

Practical Applications

The study aims to explore the key design features that support building occupants’ health, well-being, and productivity in office buildings. Building occupants’ health, well-being, and productivity are the three aspects that can be defined as WELL per the WELL Building Standard. The poor indoor environment of office buildings can negatively impact health and well-being and decrease employee productivity, which results in organizational losses. Hence, design features that support building occupants’ health, well-being, and productivity should be considered for office buildings. In this study, 11 key design features have been identified to support occupants’ health, well-being, and productivity for office buildings: air quality, clean drinking water, comfortable artificial lighting, adjustable workstation, comfortable temperature, sufficient space, security system, safety at parking lots, cleanliness, efficiency in building services, and safe design. With reference to the key design features, clients can stipulate requirements for WELL office buildings, and design consultants can comprehensively integrate the key design features into office buildings. The study also raises public awareness about the value of WELL building in delivering a quality lifestyle, overarching human health, well-being, and productivity.

Abstract

This study focuses on sound isolation performances of original timber-framed interior wall and floor components in traditional-framed dwellings in Turkey and 19th century mud-brick samples used as infill within the timber frame. The acoustical ramifications of some retrofits proposed in the contexts of minimum intervention and refunctioning the traditional dwellings are assessed in reference to the relevant standards. Field measurements show that sound isolation performances of the original timber-framed wall and floor are ineffective. The results of this study show that acoustical retrofits applied on the original wall keeping its wood lath and mud-brick infill are about 5–7 dB in the weighted sound reduction index (R_W) and are more effective than those applied on the reconstructed wall. Sound transmission loss values of 50- and 100-mm-thick authentic mud samples are 22–38 and 30–43 dB, respectively, between 125 and 4,000 Hz. The sound absorption coefficient at mid frequencies and the noise reduction coefficient of 50-mm-thick mud samples are 0.28 and 0.23, respectively. These results signal the importance of keeping traditional construction techniques of wall and floor during retrofits to improve the sound isolation performance. Adobe mixtures similar to the 19th-century mud-bricks can be of guidance for the production of innovative soundproofing earth-based building materials.

Practical Applications

Occupants living in traditional timber-framed houses suffer from noise-related problems even after these dwellings undergo repair works. According to field measurements, traditional timber-framed wall and floor components in these dwellings have inadequate sound isolation properties. On the other hand, studies show that mud-brick used as infill within the timber walls and floors, as well as mud plaster covering the wood lath, are important layers and help reduce noise transmission between the rooms in the dwellings. This means that traditional mud-based materials should be kept during retrofit works. Laying carpets or filling the voids at door edges and timber floor surfaces are minimum interventions but not enough to eliminate the noise passage. If one side of the timber-framed wall is covered with thin and insulated drywall, it provides sufficient sound insulation between the rooms. When enhanced sound isolation is needed, for instance, when a room is refunctioned as a meeting room during renovations, a separate mounting of drywall and separate mounting of timber ceiling are required to be done. This means that drywall or timber ceiling is attached in a way that does not touch the existing sublayer.

Office buildings, characterized by high internal heat gains, represent a major share of energy use, mainly due to HVAC systems, especially in commercial facilities. Such energy use becomes more significant in locations with harsh climatic conditions. The careful design, selection, and operation of HVAC and energy systems, however, can contribute to major reductions in the energy use in buildings. In this paper, we present the outcomes of a study conducted to assess the impact of HVAC operational strategies on energy use in office buildings in the hot and humid climate of Saudi Arabia. The study utilized detailed building-energy simulation coupled with utility-use data. The results revealed annual electrical energy savings ranging from an average of 1.9% for each 1°C increase in the thermostat setpoint temperature up to 42.4%, when limiting HVAC system operation to occupied hours only. On an average, there was about a 1.4% penalty in the annual energy for each hour of increase in the HVAC system start-up time. However, this penalty should not be avoided at the expense of compromising thermal comfort. In summary, a combination of appropriate HVAC operational strategies can have a significant impact on a building’s annual energy savings, as demonstrated in the presented case study.

Abstract

This paper investigated the effect of individual differences and the type of heating system on the perceived thermal comfort condition, neutral temperature, and thermal sensitivity in cold outdoor air conditions. Three types of individual factors, such as gender, temperament, and thermal past experience, were studied and compared in this paper. According to the results, temperament and thermal past experience directly influenced the occupants’ thermal preference and indirectly influenced the thermal sensation by affecting their clothing level. However, the effect size of such variations was negligible. The type of heating system had the most significant impact on the neutral temperature, with a mean difference of 2.8°C. Individual factors did not have a direct impact on the neutral temperature. However, thermal sensitivity was influenced by an individual’s temperament. Occupants with a cold temperament were more sensitive to the variation in the running mean outdoor temperature (Trm) than those with a warm temperament. When the results were compared with the predictions by the adaptive thermal heat balance (ATHB) and the predicted mean vote (PMV) models, it indicated that if the control condition over the heating system became limited, there would be no (i.e., very low) behavioral, physiological, and psychological adaptation. However, by creating an opportunity to control the heating system, thermal adaptation could be reached at a lower temperature under cold outdoor air conditions.

Practical Applications

Comfort is subjective and influenced by environmental factors and personal differences. For example, individuals might feel different and hotter or cooler at the same ambient temperatures. In addition, individuals could adapt to the environment and afford their comfort with lower costs than the heat predicted mean vote (PMV) and the cooling load calculation showed. The results of this paper could help to understand why people have different thermal perceptions under the same environment and might lead to the identification of the important nonenvironmental factors that impact the perceived feeling of health, well-being, and educational performance. Therefore, influencing decision-making during the design and maintenance of educational buildings. The results indicated that individual differences influenced the level of clothing and occupant preference. These differences influenced the variation in occupants’ thermal sensitivity to indoor and outdoor air temperatures. However, they had a negligible influence on the neutral temperature. The heating systems had the most impact on the neutral temperature. The opportunity to control heating systems could lead to the thermal comfort condition being achieved at a lower temperature in cold outdoor air temperatures, which could reduce energy consumption.