Buildings, Volume 9, Issue 8 (August 2019) – 16 articles

Urbanization trends have changed the morphology of cities in the past decades. Complex urban areas with wide variations in built density, layout typology, and architectural form have resulted in more complicated microclimate conditions. Microclimate conditions affect the energy performance of buildings and bioclimatic design strategies as well as a high number of engineering applications. However, commercial energy simulation engines that utilize widely-available mesoscale weather data tend to underestimate these impacts. These weather files, which represent typical weather conditions at a location, are mostly based on long-term metrological observations and fail to consider extreme conditions in their calculation. This paper aims to evaluate the impacts of hourly microclimate data in typical and extreme climate conditions on the energy performance of an office building in two different urban areas. Results showed that the urban morphology can reduce the wind speed by 27% and amplify air temperature by more than 14%. Using microclimate data, the calculated outside surface temperature, operating temperature and total energy demand of buildings were notably different to those obtained using typical regional climate model (RCM)–climate data or available weather files (Typical Meteorological Year or TMY), i.e., by 61%, 7%, and 21%, respectively. The difference in the hourly peak demand during extreme weather conditions was around 13%. The impact of urban density and the final height of buildings on the results are discussed at the end of the paper. Full article

In the construction community, underground construction is perceived as being significantly more costly and more energy-consuming than comparable surface construction. Although the literature is scarce, studies that have attempted to quantify this difference tend to compare built projects in heterogeneous conditions. The objective of this article is to present the results of life cycle cost and energy consumption simulations conducted as part of the Deep City project at the École Polytechnique fédérale de Lausanne in Switzerland. This article begins by examining the preconceptions the construction industry seems to have about underground construction as reported in the press from 2007 to 2017. Then, we present the method and results of two unpublished studies on the differences in costs and energy consumption of a hypothetical commercial building project in two different geological contexts. We find that energy consumption can be 15% higher but also 4% lower. We also find that underground construction in unconsolidated sediment ground is approximately 23% more expensive, while only 10% in bedrock, which is significantly lower than the 200% to 300% differentials reported in previous studies. We attribute this to the level of detail of our studies, the inclusion of ground conditions, and conclude that our results help to dispel certain misconceptions about underground construction, which can contribute positively to urban sustainable development goals. Full article

This paper explores a blend of digital and traditional methods to inform about a city’s popular spaces. Using locational data from social media platforms including Twitter, Facebook, and Instagram, along with using participatory field surveys and direct observations and combining insights from architecture and urban design literature, this study reveals popular socio-spatial clusters in the city of Chicago. The locational data of photographs were visualized by using geographic information systems, and they helped in producing heat maps that showed the spatial distribution of posted photographs. The geo-intensity of photographs illustrated the areas that are the most visited in the city. The study’s results indicate that the city’s most popular places include Millennium Park, Maggie Daley Park, Navy Pier, the Magnificent Mile Gateway, the Inner Loop, the Water Tower Area, the River Confluence, Museum Campus, Urban Giants, Grant Park, and the River City complex. The findings elucidate that social media plays an important role in promoting places and thereby sustaining a greater interest and stream of visitors. Consequently, planners should tap into the public’s digital engagement in city places to improve tourism and the economy. Full article

This paper presents a holistic decision support tool developed for use during the early stages of facade design. The tool is based on the interdependent relationships between facade performance, facade parameters, and conditions (environmental and spatial). It assumes that a decision maker has the ability to enhance the performance of a facade by making proper decisions on the design parameters in line with the conditions. However, since facade performance has various aspects (sometimes conflicting) to be considered at once, it is hard to predict the impacts of decisions on the overall performance. A single design decision may increase the performance in one aspect while decreasing it in other aspects. The tool aims to function as a guide to decision makers by indicating the impacts of design decisions on different functional aspects of facade performance from a holistic point of view. Functional requirements included within the tool are safety requirements such as structural stability and fire protection, health-related requirements such as weather protection (protection against water, air, and moisture), and requirements related to the well-being of the users such as thermal, visual, and acoustic comfort. Information provided in the tool is based upon an extensive literature review and structured as an Excel spreadsheet. Full article

Ulaanbaatar (Mongolia) is the coldest capital city in the world with approximately 98% of its heating demand satisfied by means of coal-burning stoves. This leads to enormous air pollutant emissions, with Ulaanbaatar being one of the top five most polluted cities in the world. In this study, an innovative solar hybrid heating system for the Mongolian scenario was used, which was based on the operation of a solar field composed of four series-connected evacuated tube heat pipe collectors, coupled with a thermal energy storage. The solar hybrid heating system was simulated and analyzed using the software TRNSYS. The simulations were designed to satisfy the heating demand of a typical single-family detached house located in Ulaanbaatar and were carried out with and without considering the soiling effects on the solar system operation. The overall performance of the proposed plant was compared with those associated with different fossil fuel-based Mongolian conventional heating systems, in order to assess the potential energy, environmental and economic benefits. The results highlighted that the proposed plant allowed for the obtainment of significant reductions in terms of primary energy consumption (up to 34.6%), global CO₂ equivalent emissions (up to 52.3%), and operating costs (up to 49.6%), even if the expected return on the investment could be unacceptable. Full article

There is huge market potential for energy refurbishment solutions in European buildings. This paper analyzes the challenges related to using a multifunctional energy efficient façade system, the “Meefs” system, in retrofitting multi-family apartment buildings. Similar challenges often occur also in other comparable façade renovation solutions. The focus is on hygrothermal performance even as other aspects are also discussed. After introducing the hygrothermal performance challenges of the Meefs system, numerical case analyses are performed in three different climatic conditions. The results for 26 cases are presented. A core result is that the drying of any exterior renovation system is mandatory to guarantee safe operation in different European climate conditions. This emphasizes proper design needs in all climates. Based on the analyses, design recommendations can be given for the Meefs system. In Central and Northern European climates, the system contains challenges which may hinder implementation in practice. Full article

Natural ventilation is the most common passive cooling system in livestock buildings. The aim of this research is to assess airflow distribution inside a free-stall barn for dairy cows by computational fluid dynamics (CFD) modelling and simulation. The model is validated by using the average values of experimental data acquired in a free-stall barn, which is considered relevant because it is located in a region characterised by hot climate conditions during the summer that could induce animal heat stress. Simulations are carried out in steady-state conditions, and simulated data are validated by the average values of air velocity measurements. Since the modelled air velocity distribution in the barn fits the real one well, the CFD model is considered reliable to simulate other conditions. The application of the proposed CFD model in the simulation of specific building design alternatives could be aimed at studying the related airflow distribution in order to find the best configuration. Full article

The growing pressure to ensure sustainable construction is also associated with stricter demands on the cost-effectiveness of construction and operation of buildings and reduction of their environmental impact. This paper presents a methodology for building life cycle cost estimation that enables investors to identify the optimum material solution for their buildings on the level of functional parts. The functionality of a comprehensive model that takes into account investor requirements and links them to a construction cost estimation database and a facility management database is verified through a case study of a “façade composition” functional part, with sublevel “external thermal insulation composite system (ETICS) with thin plaster”. The results show that there is no generally applicable optimum ETICS material solution, which is caused by differing investor requirements, as well as the unique circumstances of each building and its user. The solution presented in this paper aims to aid investor decision-making regarding the choice of the building materials while taking the Life Cycle Cost (LCC) into account. Full article

The effects of seismic actions on reinforced concrete (RC) structures are strongly influenced by the dynamic behavior of their materials. It is crucial to find a simple definition of the natural frequencies of reinforced concrete buildings, particularly in relation to both principal and secondary elements constructing the reinforced concrete building type. This paper firstly presents a comparison with the ambient vibration surveys. An analysis model of different stages of construction of the reinforced concrete masonry wall was compared using the finite element software. In the second step, structural responses of the model were investigated by means of static analysis. Three main types were examined: Bare frame for one, two and three storeys; brick-walled; and coated cases. Modal analysis is carried out by ABAQUS software starting from the deformed building, to provide the natural frequencies and mode shapes. For the natural frequencies, a good agreement is obtained between analytical and experimental results. Furthermore, the comparison results between different cases show that the application of the plaster work increases the lateral stiffness and has significant effects on the dynamic response of the buildings. Full article

The Life Cycle Cost (LCC) analysis on selected alternative systems was carried out to reduce the demand for potable water and energy in a detached house designed in accordance with the concept of environmentally friendly house. The tests included a rainwater harvesting system, graywater recycling system, solar panels, photovoltaic panels, air heat pumps, ground heat pumps, wind turbines, drain water heat recovery units, and biomass boilers. The analysis was made for many investment variants where different combinations of the mentioned solutions were applied. In addition to the LCC analysis, some tests were also carried out to determine an impact of the investment options on the environment. This was done by calculating CO₂, SO₂, NO_x, CO and dust emissions. The research was carried out for a different number of occupants and variable levels of water consumption, which allowed determining the impact of these parameters on the results obtained. They showed that for any of the computational cases the traditional option of the installation was not the most advantageous solution in financial and environmental terms, and the systems in question could be an alternative to this option. Thanks to their implementation, the consumption of fossil energy resources and natural water resources will be reduced, and the emission of pollutants will be limited, which will contribute to an improvement of the natural environment. Full article

The glass curtain wall system is an architectural, functional innovation where failures of insulation systems create areas of reduced resistance to heat transfer—thermal bridges—during a building’s operational lifetime. These failures enable energy flows that trigger unanticipated temperature changes and increased energy consumption, ultimately damaging the façade structure and directly impacting occupants. Our study aims to design and test an innovative method for rapidly identifying thermal bridges in façade systems, with minimum or no occupant disturbance. The research focus is in the classification of damage as either a local failure or as being related to a poor systematic construction/assembly. A nontraditional approach is adopted to survey an entire fully operational building using infrared thermography and an unmanned aerial vehicle (UAV) using a noncontact infrared camera mounted on and operated from the UAV. The system records the emissivity of the façade materials and calculates the thermal radiation to estimate localized temperatures. The system records thermal radiation readings which are analyzed using graphs to be compared with the American Society of Heating, Refrigerating and Air Conditioning Engineers (ASHRAE) standards, under ideal conditions using the THERM software. The results enable discussion relating to the most common failure areas for existing structures, facilitating the identification of focus areas for the improvement of construction methods through improved processes. Full article

The envelope structures of buildings are exposed to heat-humidity conditions. The heat and humidity flow through these structures depends on the boundary conditions of the indoor and outdoor environments. This paper shows different initial conditions for the determination of temperature spread. The aim is to bring certain results of temperature calculated considering the initial conditions. When temperature changes, heat flow also rapidly changes. In certain specific cases, it is necessary to consider the initial conditions of temperature—for example; when transient energy simulations of real buildings are carried out. The reasons as to why it is necessary to consider the initial conditions, are shown in the examples of one-layer assemblies. The test walls exposed to the transient hygrothermal conditions are placed in the outdoor test cell. The cell has a stable temperature and relative humidity, and outdoor weather conditions change. The measured data on these walls and the calculated values of the temperatures in the wall structure, according to the different initial conditions, are compared. The average difference of the mean by the simulation and the measured values is significant. For a simulation time of about five days, the initial condition for calculating the temperature in the center of the masonry is necessary. Full article

Hanok is a building style in Korean traditional architecture that presently supports a specialty of urban scenery and residential environment for regeneration in Korea. However, it is difficult to review or evaluate for the performance of Hanok, and there is no definite standard that can be applied to it yet. Therefore, it is necessary to establish the evaluation system of the residential performance of Hanok, and its concept model of the habitability performance needs to be derived in order to develop an evaluation system for the residential performance of Hanok. For this study, its evaluation factors have been classified into three major aspects such as the architectural space, the village complex, and the sustainability. This study, then, has attempted to build an evaluation system composed of proven assessment items or factors and performed AHP (Analytic Hierarchy Process) analyses with certified experts in the Hanok field and applied the relative importance among the evaluation items. Finally, this research has proposed an evaluation model of the habitability performance of Hanok. As a result of applying the assessment model for weighted habitability performances, the proposed evaluation system has been implemented as the inherent value of Hanok and its objectivity to be a major sustainable form of regeneration for contemporary residency in Korea. Full article

Dynamic displacement measurement of objects can be challenging due to the limitations of conventional methods and pricey instrumentation of unconventional methods, such as laser scanners. In this research, Close Range Photogrammetry (CRP) is used as an affordable non-contact method to measure 3D dynamic displacements. It is proposed as a reliable alternative to traditional dynamic deformation measurement methods such as displacement sensors or accelerometers. For this purpose, dynamic displacements of a three-dimensional one-story building frame model on a one-dimensional shake table are determined by using the traditional method of attached accelerometer and CRP. The results of the CRP method are compared with the results of the traditional methods as well as numerical models. The results show a good agreement which evidences the reliability of the CRP with regular cameras. Full article

Researchers have explored Building Information Modeling (BIM) utilization on complex buildings. However, limited research has been conducted investigating BIM implementation on simple projects. This study explored the perceptions of Architects, General Contractors and Owners regarding the project characteristics that impact successful BIM implementation, and the realized benefits thereof, on complex commercial buildings versus parking garages. A survey comprised of the project characteristics and realized benefits of BIM implementation identified by Dodge Data & Analytics was distributed. Exploratory Factor Analysis was conducted to identify the empirical groupings of successful BIM implementation characteristics and realized benefits thereof. Factor means were calculated and compared using ANOVA and t-tests. Statistical comparisons revealed no significant differences by building type. For project stakeholders, a significant difference was only observed on owner’s mean perceptions of technology-related characteristics when compared to architects. Previous research indicates that Architecture, Engineering, and Construction (AEC) stakeholders believe BIM is beneficial for large and complex projects. With the exception of technology-related project characteristics, findings reveal no statistical differences for project characteristics impacting successful BIM utilization or the realized benefits of BIM implementation given building type. This finding provides empirical evidence that various stakeholder groups view BIM as a universal AEC process that provides benefits on both complex and simple projects. Full article

Modern methods of designing and testing concrete must be extended to appropriate material engineering approaches. It is then crucial to link the properties of concrete with its structure described in a quantitative way. The aim of the article was to present the results of research on concretes modified with three additives: Silica fume (SF), activated fluidal ash (FA), and metakaolinite (MK). The concretes were tested for compressive strength, fracture toughness (determining critical stress intensity factor K_Ic^S and elastic modulus E). Also, stereological and fractal tests were performed. The research program covered three separate experiment plans, adopting the water/binder ratio and the additive/binder mass ratio as the independent variables. The results of experiments and their analysis proved a statistically significant relationship between fracture morphology (fractal dimension D) and concrete composition and fracture toughness. A higher fractal dimension was found in concretes with a higher content of cement paste and a lower content of additive. No significant effect of the type of additive used in the above dependence was found. An original method enabling the determination of mechanical properties of concrete with no need for destructive testing has been developed. Full article