Buildings — Open Access Journal

The first two decades of the twenty-first century represent a major milestone in skyscraper developments. By analyzing extensive data, the research presented here contrasts building activities of skyscrapers before and after the turn of the 21st century. It examines tall buildings in the world’s major continents (Asia, Europe, North America, Oceana, Middle East, South America, Central America, and Africa) and their respective cities including Shanghai, Beijing, Shenzhen, Bangkok, London, Moscow, New York, Chicago, Miami, San Francisco, Melbourne, Sydney, Dubai, Doha, Riyadh, Tel Aviv, São Paulo, Panama City, Mexico City, and Nairobi. By using nearly 40 tables and 80 maps, the paper highlights the rapid activities of building significant skyscrapers at greater heights, elucidates the changes in functions and services, and delineates shifts in spatial patterns and visual impact. Full article

With a low rate of new building construction and an insufficient rate of existing building renovation, there is the need to step up the pace of building renovation with ambitious performance targets to achieve European Union (EU) climate change policies for 2050. However, innovative technologies, including, but not limiting to, plug and play (PnP) prefabricated facades, information and communications technology (ICT)-support for building management systems (BMS), the integration of renewable energy systems (RES), building information model (BIM) and building performance simulation models (BPSM), advanced heating, ventilation, and air conditioning (HVAC), advanced geomatics, 3D-printing, and smart connectors, cannot alone solve the problem of low renovation rates of existing buildings in Europe that is hindering reaching of EU-wide targets. A workshop was held at the Sustainable Place Conference 2018 to present, with an integrative approach, the experiences from four H2020 innovation actions, i.e., 4RinEU, P2ENDURE, Pro-GET-OnE, and MORE-CONNECT, which were united by their central aims of improving building energy performance through deep renovation practices. This article presents the outcomes of the joint workshop and interactive discussion, by focusing on technical, financial, and social added values, barriers and challenges, in the context of the building renovation processes tackled by the four projects. Conclusive remarks converge on the identification of open questions to address future innovation opportunities, as well as some recommendations to be used at a policy level and/or in future implementation projects. Full article

Active shooter incidents typically transpire quickly. Research reveals that 70 percent of active shooter incidents end in less than 5 min, and that a majority of incidents are over before law enforcement arrive on scene. This study analyzes the level of preparedness among a sample of faculty members on executing “Run, Hide, Fight” in two university buildings that range in layout complexity. It also analyzes design challenges impacting response time for a sample of police officers. A visibility graph analysis (VGA), a new architectural based simulation tactic, was conducted to measure visual exposure and access, the legibility of layouts, and the ease of wayfinding within these two buildings. The findings showed that VGA measures explained the perceived level of preparedness among faculty members, and the importance of visibility to the police when they clear the building room by room. These measures may have the ability to identify the risk of exposure to shooters while attempting to run or hide, and to identify potential hidden spots in any floor plan. Full article

A focal point of ongoing research is matching the energy demand in the built environment to the energy supply from onsite generation, to maximize the self-consumption, and from the energy grids, to lower energy costs and reduce peak loads on the system. Energy flexibility addresses this task by modulating the energy demand in a building according to dynamic criteria such as electricity prices or onsite generation. This study addresses the potential of building performance simulation with real time rule-based control that provides energy flexibility based on onsite generation and hourly electricity prices, prioritizing energy matching, and reducing costs. The novelty relies on investigating four sources of energy flexibility simultaneously: shiftable machine loads, charging/discharging of batteries, hot-water storage tanks, and the building’s mass. The energy matching and flexibility actions provided a decrease of up to 4% in annual energy costs, yet risk increasing the cost by 9% when the savings are offset by the increase in the energy demand. As well, the method for price categorization strongly influences the cost performance of the flexibility actions. The outcomes of this study provide insight to energy flexibility sources in nearly-zero energy buildings and how their outcomes are affected by price thresholds. Full article

A simplified approach to calculate the daylight glare comfort class (imperceptible, perceptible, disturbing, or intolerable glare) on annual basis and for a grid of points in a space is presented. This method relies on the calculation of the vertical illuminance (E_v) for each grid point only, which is compared to an E_v threshold value for each daylight glare comfort class. These E_v threshold values are determined through a comparison with the Daylight Glare Probability (DGP) values on an annual basis through a fault-detection technique, for a reduced number of points. Compared to an annual calculation of exact DGP values on a certain grid, this approach is able to evaluate the daylight glare comfort classes only, but it is less time consuming. The paper presents and critically discusses this simplified method by means of its application to different case-studies: south and west oriented office in Turin (Lat 45.1° N), in which the DGP is assessed for three points in the space, considering glazing with different transmission properties (specular or scattering) and visible transmittances, as well as three operable internal shading systems (one venetian blinds and two roller blinds, for solar or glare control). For the presented case studies, the average error in the classification of the space according to daylight glare comfort classes is below 5% when comparing this simplified approach to related DGP values. Full article

This paper investigates various building material effects on the cooling load requirements of a typical two-floor house located in the Midwest region in the USA. A survey was done for various building materials along with their prices in the US market. Various building walls, lighting, window glazing, and insulations were used for simulation as single and combined cases. The return on investment from savings in the electrical load consumption against the materials cost was investigated. It was found that the best single case savings and investments were for cases when lights were changed from incandescent lighting with 20 W/m² to fluorescent bulbs, or when using double skinned walls with 5 cm rock wool or expanded polystyrene insulation. Combined cases, combining more than one single change, offered more reductions in cooling loads but were associated with higher initial costs and, thus, longer returns on investment. The best case recommendation was for buildings with a 20 cm hollow concrete block (HCB) when combined with fluorescent lights and double pane heat-absorbing glazing for windows. Although these recommendations were for a typical house in the Midwest region of the United States, a similar analysis could be adopted by designers and building owners to optimize the energy consumption in their buildings. The final design decision should be based on an optimum correlation of the air-conditioning units’ size and cost, running and maintenance costs, the return on the investment duration, and the available usage area in the building. Full article

Open-plan offices have lower construction costs, allowing for significant savings in space and, according to designers, facilitate communication between workers, thus, improving collaboration, as well as the exchange of ideas. For these reasons, this type of office has become widespread, while highlighting numerous limitations and various problems. These include the control of anthropic and electromechanical noise. In this study, measurements of the noise emitted by a heating, ventilation, and air conditioning (HVAC) system were carried out in an open-plan office. The average spectral levels in a 1/3 octave band were compared through correlation analysis, to identify any redundant data. A model was then adapted to evaluate the importance of the variables, in order to classify the characteristics, by importance. To reduce the number of predictor variables, a selection analysis of the characteristics was carried out. A subset of predictors was extracted to be used to produce an accurate prediction model. Finally, a model based on recursive partitioning, to detect the operating conditions of an HVAC system, was developed and applied, so as to provide insights into the development and application of this technique, in these contexts. The high accuracy of the model (Accuracy = 0.9981) suggests the adoption of this tool for several applications. Full article

Radiative cooling is a well-researched area. For many years, surfaces relying on radiative cooling failed to exhibit a sub-ambient surface temperature under the sun because of the limited reflectance in the solar spectrum and the reduced absorptivity in the atmospheric window. The recent impressive developments in photonic nanoscience permitted to produce photonic structures exhibiting surface temperatures much below the ambient temperature. This paper aims to present and analyze the main recent achievements concerning daytime radiative cooling technologies. While the conventional radiative systems are briefly presented, the emphasis is given on the various photonic radiative structures and mainly the planar thin film radiators, metamaterials, 2 and 3D photonic structures, polymeric photonic technologies, and passive radiators under the form of a paint. The composition of each structure, as well as its experimental or simulated thermal performance, is reported in detail. The main limitations and constraints of the photonic radiative systems, the proposed technological solutions, and the prospects are presented and discussed. Full article

Growing ageing population today may be necessitating building design decision makers to reconsider the indoor environmental quality (IEQ) standards in a way that accommodates senior occupants’ diverse and individual needs and demands. An experience design approach to rationalising and individualising end-user experience on how to utilise tangible products may serve to reflect user perceptions. Generally, architectural design practices tend to incorporate neither IEQ monitoring and analysis data, nor environmental experience design today. In response to the need for filling this gap, the authors of this paper conducted a feasibility study previously that led to structuring and defining an ‘Environmental Experience Design’ (EXD) research framework. Based on the previous case study on the collective spatial analysis and IEQ monitoring results, this paper further explored the usability and applicability of this proposed EXD framework particularly to the previously documented aged care facility in Victoria, Australia, which has been stressing active ageing agendas. This EXD framework usability experiment helped to build the capacity for engaging the subjectivity and objectivity of end users’ expectations, desires, and requirements in the architectural design thinking process. Nonetheless, due to the limitation of this initial and fundamental usability study’s resources and the objective, the necessity of adjusting the scale and scope of EXD analyses emerged. Moreover, the universality of this EXD research framework usage under various architectural typologies and user conditions yet require further attempts and investigations. Full article

The courtyard is a common and traditional architectural concept in Middle Eastern countries, especially Iran. This study presents practical solutions to arrive at the optimal form and features of a courtyard based on this traditional architecture to cope with the hot and arid climate of Isfahan, Iran. A model using the ENVI-met 3.1 software was used to simulate the courtyard orientation, the height of the wall enclosure, the albedo of the materials and the vegetation level in Isfahan. As the first step of the simulation, different orientations were simulated. Based on the results, the northern courtyard is recommended as the optimum orientation for the remainder of the simulation process. A high wall enclosure is recommended in the second step of simulation to ensure cool temperatures at noon and warmth at night. In the third step, it is advised to use low-albedo material in the courtyards to avoid the extra reflected radiation of used materials on the inhabitants. The final step suggests that more than 50% of the courtyard plan should be covered by greenery to ensure thermal comfort in the courtyards. Based on these suggestions, designers can create more sustainable courtyards that are better suited to the hot and arid climate of Isfahan. Full article

Three-dimensional (3D) printing technologies are transforming the design and manufacture of components and products across many disciplines, but their application in the construction industry is still limited. Material deposition processes can achieve infinite geometries. They have advanced from rapid prototyping and model-scale markets to applications in the fabrication of functional products, large objects, and the construction of full-scale buildings. Many international projects have been realised in recent years, and the construction industry is beginning to make use of such dynamic technologies. Advantages of integrating 3D printing with house construction are significant. They include the capacity for mass customisation of designs and parameters to meet functional and aesthetic purposes, the reduction in construction waste from highly precise placement of materials, and the use of recycled waste products in layer deposition materials. With the ultimate goal of improving construction efficiency and decreasing building costs, the researchers applied Strand 7 Finite Element Analysis software to a numerical model designed for 3D printing a cement mix that incorporates the recycled waste product high-density polyethylene (HDPE). The result: construction of an arched, truss-like roof was found to be structurally feasible in the absence of steel reinforcements, and lab-sized prototypes were manufactured according to the numerical model with 3D printing technology. 3D printing technologies can now be customised to building construction. This paper discusses the applications, advantages, limitations, and future directions of this innovative and viable solution to affordable housing construction. Full article

The study aims to assess the impact of shear walls on active vibration control of the buildings. It has evaluated the design of a smart 20-story building equipped with an Active Mass Damper to mitigate earthquakes. The design has combined shear walls with an Active Mass Damper (AMD) added on the top floor. The control configuration used a force actuator combined with a displacement sensor and was examined with Direct Velocity Feedback. The effect of the presence of wall braces in the design of tall buildings on the performances as well as the control effort has been studied. The results have stated that the shear walls designed for mitigating earthquake loads are capable of reducing the displacement of the tall building somewhat but failed to reduce the acceleration of the top floor. The combination between shear walls and AMD has incredible damping capability on the displacement and acceleration of the building. However, the shear walls tend to increase the control cost since they require more control energy. Full article

A mathematical model and robust numerical solution algorithm for radiator heating of an arbitrary room is presented in this paper. Three separate and coupled transient thermal energy equations are solved. A modified transient heat conduction equation is used for solving the heat transfer at multi-layer outer walls and room assembly. Heat exchange between the inner walls and the observed room are represented with their own transport equation and the transient thermal energy equation is solved for radiators as well. Explicit coupling of equations and linearization of source terms result in a simple, accurate, and stabile solution algorithm. Verification of the developed methodology is demonstrated on three carefully selected test cases for which an analytical solution can be found. The obtained results show that even for the small temperature differences between inner walls and room air, the corresponding heat flux can be larger than the transmission heat flux through outer walls or windows. The benefits of the current approach are stressed, while the plans for the further development and application of the methodology are highlighted at the end. Full article

Changes to building codes that enable use of materials such as cross-laminated timber (CLT) in mid- and high-rise construction are facilitating sustainable urban development in various parts of the world. Keys to this are the transition to multi-performance-based design approaches along with fewer limitations on heights or the number of storeys in superstructures constructed from combustible materials. Architects and engineers have increased freedom to apply new design and construction concepts and methods, as well as to combine timber with other structural materials. They also have started to develop wall arrangements that optimise interior space layouts and take advantage of the unique characteristics of CLT. This paper discusses the seismic response of multi-story buildings braced with a CLT core and perimeter shear walls anchored to foundations and floor platforms using modern high-capacity angle brackets and hold-downs, or X-Rad connectors. Linear dynamic finite element (FE) models of seismic responses of superstructures of various heights are presented, based on experimentally determined characteristics of wall anchor connections. Particular attention is given to fundamental vibration periods, base shear and uplift forces on walls, as well as inter-story drift. Discussion of FE model results focuses on structural engineering implications and advantages of using CLT to create shear walls, with emphasis on how choice of wall anchoring connections impacts the possible number of storeys and configurations of superstructures. Employing CLT shear walls with X-Rad or other types of high capacity anchoring connections makes possible the creation of building superstructures having eight and potentially more storeys even in high seismicity regions. However, it is important to emphasise that proper selection of suitable arrangements of shear walls for CLT buildings depends on accurate representation of the semi-rigid behaviors of anchoring connections. The linear dynamic analyses presented here demonstrates the need during engineering seismic design practices to avoid use of FE or other design models which do not explicitly incorporate connection flexibilities while estimating parameters like fundamental periods, base shear and uplift forces, as well as inter-story drift. Full article

This paper reports the acoustic issues of open plan office environments. According to a detailed research based on the scientific literature of the most suitable acoustic descriptors recommended for the open plan offices analysis, the main typological-functional configurations of these environments have been analyzed in order to identify six spatial typologies. The variation of acoustic parameters of these typologies has been evaluated by using a sound pyramid tracing software. The analysis procedure was calibrated in a case study of an office environment, where a measurement campaign was carried out. Results point out that the acoustic improvement of open plan offices can usually be achieved by introducing a sound absorbing false ceiling and dividing panels between working positions, but there are different issues depending on spatial geometries of the office. Better results are referred to office typologies characterized by reduced height and equal plan dimensions. Full article

Australia’s National Disability Insurance Scheme Specialist Disability Accommodation (NDIS SDA) program anticipates new, disability specific, housing stock being built by private investors incentivized by cash payments and rental income. To date, very few new SDA dwellings have been constructed and the majority of the research and analysis of the program’s potential has been in the context of apartment construction in major capital city markets in Australia. This paper uses a hypothetical case study of building SDA accommodation in a discrete regional Indigenous community, Yarrabah, in Queensland. It investigates underlying assumptions within the scheme, particularly around the relationship of land to investment outcomes, as well as cultural considerations. An important aspect is to test how effectively the design guidelines associated with the scheme translate into an appropriate built form that is culturally and environmentally appropriate in locations outside major urban centres. The results suggest that housing actors from the not-for-profit sector may benefit from the SDA at the expense of profit-driven, market-based housing developers, and that the SDA design categories offer limited flexibility for participants with changing care needs, potentially restricting resident continuity in occupancy and ongoing return on investment. The work offers an early assessment on the workability of the SDA in the context of housing investment in a new market for the private housing industry. Full article

As the construction sector continues to be associated with highly energy-intensive practices leading to excessive carbon emissions, governments in many countries are promoting a shift towards greener building practices, like the use of wood in multistory construction (WMC). Meanwhile, local-government actors (e.g., municipalities) often act as important gatekeepers of urban development given their authority to oversee or approve zoning and land-use plans. Despite this fact, they are not much focused on in existing WMC research. This qualitative interview study serves to fill a gap by studying municipal civil servant perceptions regarding WMC, using Finland as a case study. Civil servants were asked to elicit their personal opinions on WMC, and what they perceived as favorable or unfavorable about using wood as a multistory construction material. Results show increasing support for WMC, and that this is due to key benefits made possible by the technical qualities of engineered wood products in emerging WMC projects. These products permit both the adoption of rapid construction practices that enhance citizens’ quality of living, and also the sourcing of local renewable building materials that support local industries. On the other hand, barriers to the use of wood were identified, such as inadequate information distribution, a limited number of WMC industry actors, and inefficient policy measures. Full article

Image processing methods are increasingly used in civil engineering, especially in the maintenance of concrete structures. Current digital cameras and post-processing methods allow verifying qualitatively the state of conservation of wide areas of concrete in dams and bridges. When dealing with building refurbishments and rehabilitation, it is important to verify that existing structural elements fit the requirements of the standards; in the case of structures formed by traditional RC joists, cracking of the bottom-face provides information about the serviceability of these elements. This research proposed and put in practice through experimental tests an image post-processing method for quantification of cracking (five specimens were used and calibrated). Based on a sequence of shots and through a complex step-by-step post-processing, cracks were identified and measured to calibrate this method for real purposes. The method quantifies the crack opening width and spacing by analyzing the bottom-face of the joists through the shots. Measured values of crack spacing are very similar to those predicted by the standards, while the values of crack opening width differ more from theoretical ones due to the scattering of results. However, the proposed method has been proved as suitable and useful for fast inspections of RC elements under bending. Full article

Like other kinds of projects, construction projects are exposed to uncertainty, which plays a critical role in determining the transaction cost (TC). This study explores the uncertainty factors that are associated with construction projects that substantially influence the TC. To obtain the opinions of construction professionals, a survey questionnaire was developed after identifying 30 relevant causes of uncertainty from the literature. A survey of 216 professionals was conducted in Pakistan, and the relative importance index (RII) was used to prioritize the significant uncertainty factors that escalate the TC. Based on the responses from various construction professionals, this study determined that the most significant uncertainty factors that influence TC are: competitive tendering, incomplete design and specifications, late payments, conflict management, delayed possession of sites, force majeure, and work acceleration. This study also compared and analyzed the views of project managers and consultants and found that uncertainty from internal sources has a more significant influence on TC than that from external sources. The political and environmental groups do not contribute much escalating the TC. However, uncertainties that arise from the commercial, project site, and technical groups are more of an influence on TC. This research helps practitioners and professionals to adopt integrative systems in most uncertain situations proactively to find opportunities in volatile markets to reduce the impact of uncertainty on the total project cost. Full article