Journal of Architectural Engineering

Cross-laminated timber (CLT) is a mass timber product that has recently garnered considerable attention for lateral-force resisting system (LFRS) applications. The main objectives of this study were to investigate the rocking behavior of a high-aspect-ratio (height/width) CLT shear wall without post-tensioning, and to validate a finite-element (FE) model based on the cyclic and dynamic response of the wall. To this point, high-aspect-ratio walls in the literature have primarily been post-tensioned. The testing component of this study included connector tests, quasistatic cyclic shear wall tests, and shake-table tests under four different ground motions scaled to design earthquake (DE)- and maximum considered earthquake (MCE)-level intensities. A generic shear connector was used for this study to allow for proprietary and other systems to demonstrate equivalence. The connectors were tested under shear and uplift, and shear-wall tests were performed using the Consortium of Universities for Research in Earthquake Engineering (CUREE) displacement protocol, which has been widely used for light-frame wood structures. Interstory drift (ISD) ratios in the shake-table tests ranged from 0.97% to 2.02%, and the tests demonstrated the system's ability to resist seismic loading. An FE model of the CLT wall was developed that showed good agreement with the cyclic and shake-table tests. The difference between the ISD ratios in the numerical model and the shake-table tests ranged from 5.4% to 31.3%, with an average of 17.9%, which was in good accordance with the accuracy of the existing CLT models. This system can be utilized as a retrofit option, in conjunction with light-frame wood shear walls, where lack of space may be a challenge.

Many elevated houses in coastal areas have suffered serious wind-induced damage during hurricanes; this indicates the need for better understanding of the performance of elevated homes subjected to higher wind forces or effects in open pile-supported areas. The actual direct and indirect wind-induced damage to elevated wooden residential houses in past hurricanes is briefly reviewed. Computational fluid dynamics (CFD) analysis was utilized to investigate the effect of wind angle and house elevation on the magnitude of mean negative or positive design pressures as an important variable affecting the vulnerability of the structural system. The numerical results were validated based on available experimental tests in terms of the mean pressure coefficient (C_p) over the house surfaces. The CFD results show that elevating a house can result in increased wind speed and subsequent additional turbulence effects around the house, in particular at the exposed underside. The results indicate that elevating a house does not significantly affect the C_p distribution on the roof surfaces, so that the roof uplift forces remain almost constant. However, elevating the house leads to increases in C_p at various rates over the house surfaces, including exterior walls and along the underside. The rates of such increases depend on wind direction and house elevation. Regardless of wind direction, the overturning moment acting on an elevated 1:20 scale house increases about 50% and 95%, respectively, for 0.105 and 0.21 m elevations. Considering the scope and the limitation of the study presented in this paper, more studies are needed to better understand the effect of aerodynamic characteristics of elevated houses, particularly on peak positive or negative pressures over various building surfaces.

Thermal, visual, and acoustic comfort are among the major parameters of overall occupant comfort and indoor environmental quality in buildings. Early stage design and selection of building envelope parameters require due consideration to all these three aspects of comfort to enhance envelope performance, productivity, and wellbeing of occupants. Several methodologies have been proposed by researchers for optimization of thermal and visual performance of the envelope, both individually and simultaneously, but the acoustic performance, that is, mainly noise insulation, has remained largely disregarded or left to be dealt with at a later stage. The lack of a proper methodology for simultaneous optimization of thermal and visual performance of building envelope with acoustic performance has led to degradation of the acoustic environment inside green buildings. The present study aims to propose a methodology for simultaneous optimization of the thermal, visual, and acoustic performance of the building envelope to minimize operational energy consumption and enhance thermal, visual, and acoustic comfort for the occupants.

The technological advancements of the twenty-first century have great potential for improving the construction industry’s low levels of productivity. Many companies are adopting new technologies to help them in their everyday work and automate some of their tasks. With the increased demand for skilled workers who are able to adapt to the new technological changes, it is essential for schools to provide their students with the necessary skills to enter the market and be successful professionals. This research presented the results of a Delphi study conducted to assess the level of knowledge in technological topics expected from graduates when joining the industry. The expectations were measured from the industry side and the academic side and compared based on the job position. Based on the collected results, two graduate construction technology courses were designed and described in this paper. These courses covered topics related to information modeling, reality capture, visualization techniques, generative design, robotics, and automation. The paper also assessed the use of virtual reality and collaborative online platforms for building information models for class group projects. It also discussed the benefits of using these technologies from the viewpoint of students and instructors.

There has been a good deal of discussion over the most sustainable model for development of housing in India. Planners discuss the advantages of low-rise versus high-rise development in terms of energy and cost efficiency. Shortage and high cost of land has been a justification for high-rise development. In this paper, mixed housing (EWS, LIG, MIG, and HIG), from 1 to 30 stories, has been analyzed at a city level for a fixed population for embodied energy, construction cost, and potential for CO_2e sequestration. The inference drawn from this exercise is that low-rise (1–4 stories) load-bearing development is energy and cost efficient and can accommodate the maximum number of housing units in about 4% of the land area in a city. High-rise development is 194% and 17.5% more than low-rise in terms of embodied energy and construction cost, respectively. It is also found that 100% of CO_2e can be sequestered by planting trees in available open areas in low-rise developments compared with 57% in high-rise development (30-story). Further, high-rise development results in only marginal increase in open areas after four stories. Hence, high-rise development is neither sustainable nor cost effective.

Buildings with open ground stories are more vulnerable to soft story mechanisms, which might lead to building collapse in a moderate quake. To mitigate these negative effects, retrofitting techniques typically introduce new structural elements or energy dissipation devices, which increases the deformation capacity of the soft story without modifying the stories above. However, by altering the open nature of the ground floor, these solutions fail to integrate the occupants' preferences and needs into the design process. Therefore, instead of modifying the ground floor, this study will propose a user-centered design process, which is based on separated infill walls in the upper stories, to mitigate the effects of soft story irregularity. The user-centered design strategy integrates the needs and preferences of the occupants into the design solutions of their built environment. To achieve this, two low-rise reinforced concrete buildings in Turkey were selected as case studies and subjected to structural analyses to determine whether the separation of the existing infill masonry walls reduced the lateral strength of the structure. In parallel, preliminary designs of the infill separations was developed and discussed with architects, practicing engineers, and builders. The feedback helped to develop design details to achieve the separation of the infill walls from the frames in the studied buildings. The occupants that live in the existing buildings or the surrounding areas were interviewed and presented with parametric variations of these proposals. Quantitative data suggests that separation of the infill walls is a feasible solution that could be applied to new construction and for existing reinforced concrete multistory buildings and the qualitative data that was obtained from the interviews suggested that user-centered design approaches help to develop suitable seismic mitigation strategies.

The North American Vegetated Roof Assembly (VRA—a.k.a. green roofs) market is dominated by two different types: modular vegetated roof assemblies (MVRAs) and built-in-place vegetated roof assemblies (BVRAs). In MVRA, the vegetation is pregrown in transportable trays and installed on the roof, whereas in the BVRA, the vegetation develops on the roof. In 2015, the National Research Council of Canada (NRC), in collaboration with the green roof industry and roofing industry, set the national standard for the wind resistance evaluation of MVRA. Practitioners and building authorities have widely used this standard. In 2017, NRC and the industry collaborators started a new research project on BVRA to expand the current standards. The wind performance of BVRA is highly dependent on the growth stage of the vegetation. This variable was investigated by testing four BVRA sources (S1, S2, S3, and S4) at three different growth stages, namely, as-built, 12 weeks, and 1 year of growth. The interaction between the approaching wind speed and the BVRA response was monitored by installing load cells underneath the test mock-up. The load cells were intended to capture the growth media loss as the wind flow develops over the BVRA mock-up. The wind speed at which the vegetated system’s (VS) weight reaches 85% of the initial weight was used to compute the BVRA wind performance. The tests conducted at the three growth stages permitted developing an empirical growth modifier factor (GMF). The GMF is a practical engineering solution to estimate the wind performance of a 1-year BVRA using the as-built performance data. The paper presents the development of this new testing methodology and the standardization process.

Real estate markets are ideal investment options that lead to the construction industry’s and the economy’s growth. Therefore, having appropriate investment and valuation strategies is a critical success factor. Most established valuation methods emphasize market value and economic factors and are ignorant about buildings’ technical and structural attributes. Therefore, due to the process ambiguity and lack of information access, the estimated price usually differs from the real property value. In this research, a revised valuation framework is proposed based on the life cycle cost (LCC) of residential properties, focusing on the operation phase. LCC consists of all costs related to an asset during different phases of its lifecycle, and it helps determine the net present value of the property. For systematically storing and analyzing technical and financial information, building information modeling (BIM) was proposed. Despite being widely used in the design and construction phases, its application and competitive advantage to real estate developers and managers during the operation phase are not transparent. This research benefitted from the 5D BIM model with a level of development (LOD) of 300 to increase the transparency and validity of valuation. An 18.25% difference between the calculated price of two case studies in Tehran and their inflated market prices proved this assertion.

Air-barrier systems (ABSs) are essential elements in the performance of building envelopes and they are specified in the National Building Code of Canada (NBC) to minimize the infiltration and exfiltration of air through the building envelope to control the risk of condensation. Although their primary function is to control the movement of air across the building envelope, when placed on the exterior side of the wall assembly, the barrier may also function as a water-resistive membrane, thereby reducing the movement of moisture toward the inside of the assembly. Since the publication of the Energy Code of Canada in 2014, more attention has been paid to the importance of ABS to control both heat flow and air transfer through the building envelope, which both contribute to rising costs of energy use in buildings. Recently, the Canadian Construction Materials Centre (CCMC) developed performance criteria for liquid-applied ABS. The CCMC is a recognized accreditation body that provides guidance to building officials with respect to the conformity of innovative products as alternative solutions to the NBC. In this paper, four key items are presented. First, a brief overview of liquid-applied ABS, their components and functions, and the motivation to use this product type in the construction industry is provided. Second, the qualification process for such product against requirements for compliance with the NBC in Canada and its market acceptance will be discussed. In doing so, the strategy recently adopted by the CCMC in the evaluation of innovative liquid-applied ABS will be reviewed. Third, the key performance criteria and the durability assessment for an expected 25 years of acceptable service life will be discussed. Finally, the quality control process for acceptable field applications will be briefly surveyed.

The primary goal of this paper was to answer the question: Do empirical data from real-world projects align with Design for Adaptability (DfA) strategies reported in the literature? The data and analysis presented herein suggested that when DfA strategies are present in building design (intentionally or otherwise), they indeed facilitate adaptation. Similarly, when the strategies were not present, the adaptation project was impeded. DfA strategies can contribute to circular economy by designing today’s buildings with the potential to be modified for future needs. Thus, DfA embraces the inevitability of change and allows buildings to be revitalized according to society’s evolving needs and wants. While previous journal papers, books, and design guides on this topic were based on theoretical reasoning, expert opinion surveys, practical experience, and case studies, the current paper contributed to the discussion by comparing DfA strategies from the literature with empirical data from 89 real-world building adaptations. Data were provided by 76 industry professionals and included short descriptions of the buildings’ physical features that facilitated or impeded the adaptation projects. A thematic analysis method was used to evaluate the data. Finally, the research provided practical steps for implementing adaptable design: quality documentation, open floor plans, large floor-to-floor heights, and simple designs.

Several substantial market barriers obstruct the widespread adoption of sustainable buildings. Esthetic features are amongst the main driving forces behind the marketability of buildings, thus improvement of sustainable buildings in terms of visual esthetics would enhance their marketability and thus their market intake. Nonetheless, esthetic improvement of the buildings is a challenging task because it lacks in scales and methods to measure and evaluate buildings’ facade esthetic. In this regard, this study aims to develop machine learning-based models to predict the esthetic appreciation of buildings related to their façade features. For this purpose, an artificial neural network and decision tree models are developed and validated with the results of a conducted comprehensive survey (n = 807). In addition, the impact of different window features (i.e., position, number, area, width, height, symmetry, and proportion) on housings esthetic and marketability is investigated. Results show a high level of accuracy for both models in the prediction of esthetic appreciation of buildings.

Space efficiency in supertall buildings (300m+) is one of the most critical design parameters to make a project feasible. This issue becomes even more important in office buildings where the ability to increase rental income is a crucial indication of proper planning. This study analyzed space efficiency in contemporary supertall office buildings. Data were collected from the 44 buildings through literature surveys and the case study method to examine space efficiency and main architectural and structural parameters affecting it to contribute to designing more feasible office towers. The main findings of this study indicated that: (1) central core was the most preferred type; (2) frequent use of free and tapered forms were identified; (3) composite use was dominant over steel and concrete utilization; (4) the most used structural system was the outriggered frame system; (5) space efficiency decreased as the height of building increased, where core area and planning were the most decisive factors; and (6) when groups of building form were compared with each other, no significant differences were identified among their effects on space efficiency and similar results were valid for structural systems. This study aids and directs architects in the sound planning and development of supertall office projects.

Construction contracts are known to be the most effective factor to address the challenging subject of risk-sharing between key stakeholders in a project. This study will be conducted for the early recognition of sources of uncertainty in construction contracts that are crucial to avoid when meeting the project objectives. To achieve this goal, a two-stage approach will be used. First, a text analysis method will be developed following previous research to identify key commitments. This rule-based method will rely on a lexicon database that includes promisor-determiner nouns (PDN) and obligation-maker verbs (OMV). Second, to estimate the effects of uncertainties on project objectives, a two-stage risk analysis technique based upon probability and impact estimation will be adapted. The proposed text analysis framework will be validated using MATLAB. The major contribution of knowledge from this study will be to present a text mining risk analysis-based model to assess the patterns of the risk-sharing under general conditions of contract between parties. To quantify the risks of contract obligations, the clauses of general conditions of the New South Wales Government of Australia GC21 (NSW GC21) contract will be analyzed against five project objectives. The results show that the proposed method could be effectively used to identify the main obligations of the other party in the types of contracts to develop the contract strategy for the client and the contractor.

Tensegrity is a stable self-equilibrated spatial structure composed of isolated members in compression inside contiguous tensioned components. The tensegrity hollow-rope modules can be implemented in the Architecture–Engineering–Construction (AEC) field, such as in the design of towers and bridges. Although some research is conducted based on tensegrity form-finding and structural analysis, finding the optimal form of these systems is a complicated task in terms of its geometrical complexity and nonlinear behavior. In this research, using a modified force density algorithm, a fully parametric approach is developed for tensegrity design and form-finding. It is developed as an innovative workflow for design exploration, performance evaluation, and structural optimization of the tensegrity hollow-rope systems. Then, by introducing an adaptive problem-solving algorithm, the correct functioning of the defined plugin for creating new and optimized tensegrity forms is investigated in several case studies. This method facilitates the initial design and form generation of hollow-rope tensegrity optimized nodal geometry in a fully parametric interface.

Wind-driven rain (WDR) is a primary cause of material degradation in tall buildings that affects the durability and long-term performance. This study investigates the influence of building shape on WDR exposure in tall buildings using computational fluid dynamics (CFD) simulations. Results indicate that building shape influences local flow conditions, which, in turn, influence the trajectory of rain droplets and their impingement on building surfaces. Two specific flow features were found to dictate WDR exposure: the wind-blocking effect and the separation of shear layers at leading edges of the building. Streamlined geometries with small wind-blocking regions experienced higher WDR exposure on windward surfaces. High WDR concentrations also occurred on geometric features protruding into the wind and at locations where shear layers impinge on the building surface. These findings are based on steady Reynolds-Averaged Navier–Stokes (RANS) simulations that do not consider unsteady flow features such as buffeting and vortex shedding. Nonetheless, the study provides valuable insight into the influences of building shape on WDR exposure, which could lead to better weatherproofing of these buildings.

The cost of mass timber buildings is a major point of interest to building developers and architects because it often dictates the fate of proposed mass timber projects. Cost estimation for mass timber construction has several unique aspects that differ from those of steel, concrete, and light-framed wood buildings. With the new building categories (Types IV-A, B, and C) introduced in 2021, it is important to look at cost implications of both the new and existing types (III-A and -B and IV-HT) and cost sensitivity to key design features. An automated design and cost estimation algorithm for mass timber gravity systems was developed. The algorithm includes an automated member selection and design procedure that implements strength and serviceability checks. Fire rating and design requirements were included. The final cost calculation includes material costs of wood, connection hardware, fire protection, and an estimation of installation cost. The details of the proposed algorithm are presented in this paper, together with scenario analyses on archetype design using different mass timber categories.

A new empirical design approach is presented for predicting the compression strength of lightweight fiber-reinforced polymer (FRP) sandwich panel columns. The model is simple enough to use for design purposes, yet it considers both local and global failure modes and is able to capture trends observed in experimental results. Insulated FRP sandwich panels present promising energy-efficient solutions for rapid modular construction, including wall or decking applications. To date, no straightforward design method exists for these systems, especially under compression loading, which limits their use in practice. Predicting the load-bearing capacity of these elements is complicated by the fact that several possible failure modes may occur, including global buckling, local wrinkling, face sheet crushing, or core shear failures. The proposed empirical model was calibrated using test results from 168 concentrically loaded sandwich columns with either flax FRP (FFRP) or glass FRP (GFRP) face sheets and polyurethane or polyisocyanurate rigid foam cores. A wide range of material properties, face sheet thicknesses, and slenderness ratios were considered in the analysis. The average experimental-to-predicted ratio was 1.04 with a coefficient of variation (COV) of 0.17.

Climate change is a threat. Houses we inhabit should conform to changes in the environment. The housing sector is vulnerable to climate changes, since the inhabitants are more exposed than in commercial buildings. Studies find modern sustainable buildings are at risk from thermal changes due to lower resilience from a focus on energy savings. Through simulation studies of three sustainable houses in Denmark, their viability to climate change is tested. Four thermal adaptation strategies were simulated: defensive, reactive, embedded, and air conditioning. The operative temperature and energy use for heating is registered for occupancy rooms in the buildings. The simulations show a tendency that adaptation through passive means use the same or up to 5% less energy as the unmodified buildings in the simulations but are unable to uphold thermal comfort, where active technologies use 25%–260% more energy than the baseline in 2080. Reactive strategies provided best thermal comfort in most rooms and scenarios, balancing energy and thermal environment. Air conditioning removed most thermal discomfort but increased the energy use with 45%–260% by 2080. The recommendation would be to enable upscaling of mechanical ventilation by a factor of two over the minimum regulation of 0.3 l/s/m² with the ability to bypass heat recovery, aided by passive solutions such as strategic planting of deciduous trees and solar shading to reduce energy use further.

Several efforts have decreased the environmental footprint from the construction field in developed countries. In contrast, sustainability is often overlooked in developing countries due to unstable economies, monopoly, and inadequate policies, among others. It is evident from recent studies that sustainable construction practices are urgently needed in developing countries to reinstate construction methods, which in their current state deplete resources, damage the environment, and threaten the stakeholders’ health and well-being. Venezuela, a developing country in Latin America, is currently experiencing such issues within the construction industry due to political and economic cataclysms in addition to humanitarian, environmental, and health facets. This study seeks to identify key information that will facilitate the comprehensive understanding of major barriers and drivers to the adoption of proven sustainable construction practices, particularly in Venezuela. To achieve this objective, the study conducted a systematic literature review as well as multiple focus group discussions and questionnaire surveys to construction stakeholders in Venezuela. The analysis of the survey results confirmed that there are delays in the integration of sustainable construction practices due to factors such as inflation, lack of environmental awareness, and corruption, among others. The results also highlighted that professionals with higher academic backgrounds and trained for sustainable construction practices, particularly women professionals, are more likely to advocate for such practices within Venezuela. The findings of this study contribute to two bodies of knowledge: first, the construction management through embracing sustainable planning, design, and construction within the built environment; and second, sustainable construction through encouraging the adoption of integrative project delivery methods as well as sustainable training and practices specifically in developing countries. This paradigm shift toward embracing sustainable practices in developing countries promises the reduction of environmental impacts while nurturing a healthier built environment. Moreover, it also highlights the critical need to encourage solving such barriers and ensuring a sustainable future.

In the architectural design field, a practical challenge when producing curvilinear geometry with concrete remains. Currently, the use of three-dimensional printing (3DP) technology with concrete during construction has become of interest for engineers and architects with the expectation to mitigate this type of challenge; however, the level of understanding of the construction process is unclear. This paper will present a case study for the design and construction process for a self-supporting curvilinear geometry architecture termed a multipurpose pavilion. The methods in the case study include computer-aided design, structural analysis, joint assembly, and site construction techniques. The results present the benefits and current limitations of the existing technology and could contribute as a method for 3DP design and construction.

Socially resilient housing design aims to satisfy the diverse and ongoing changing social needs of the residents. In reaction to the problem of the lack of responsiveness to changing residents' needs, the United Arab Emirates (UAE) public housing has experienced two contending responses: informal and formal. The investigations into the residents' informally constructed extensions revealed some resulting patterns of architectural design morphologies for size, shape, form, and style, utilized construction methods, techniques, and materials. These actions, although they responded to the residents' social needs, were coupled with some functional, constructional, and negative health impacts due to the residents' lack of technical experience. In addition, the formal responses largely failed to solve the inadaptability problem. Reconciling the competing formal and informal practices by building on the advantages and limiting the disadvantages of each has yielded a promising conceptual design approach for socially resilient public housing in the UAE.

The major objective in this research is to propose building transformation strategies for energy efficiency, thermal comfort, and visibility using a Bayesian multilevel modeling approach. To address the increasing energy demands and environmental responsibility, buildings in urban areas should be transformed to be highly energy efficient while satisfying human comfort. However, multivariate relationships between variables and performance outcomes make it difficult for researchers to discern comprehensive strategies for changing building forms. In this respect, this research explores transformation strategies that can consider multiple performance in urban blocks and multiple parameters in building forms using Bayesian multilevel additive modeling. The transformation strategies are established for Kyojima, Sumida-ward, Tokyo, Japan, by analyzing 870 existing buildings. The results enable city planners, building managers, or developers to predict urban block performance based on different scenarios of building topologies and typologies. The findings can contribute to planning an optimal urban buildings' retrofitting or redevelopment for future smart and sustainable communities.