Building Performance Research Articles

Outdoor Performance Analysis of Semitransparent Photovoltaic Windows with Bifacial Cells and Integrated Blinds

The stricter requirements for the energy performance of buildings are creating a market for several building‐integrated photovoltaic (BIPV) technologies, including photovoltaic (PV) windows. Herein, an innovative multifunctional PV window concept designed to enhance energy generation while providing overheating protection for better indoor thermal and visual comfort is presented. This concept utilizes bifacial c‐Si solar cell strips combined with venetian blinds, all embedded in a unique insulating glazing unit. The bifacial technology increases the energy yield by using the blinds as reflectors, directing more irradiance to the cells’ rear side. The goal of this study is to analyze the outdoor performance of this concept under real operating conditions. Twelve demonstrators are installed and monitored. Various measurement campaigns are conducted, examining the impact of different blind types, tilt angles, sun positions and sky conditions. The highest energy boosts occur when the blinds are fully closed at a 75° angle with their convex side facing outward. Blinds with the highest specular reflectance achieve a maximum performance increase of 25% on sunny days and a daily average increase of 12% compared to the case of no blinds.

Building performance modelling approaches for a detached vertical green trellis: A case study in a tropical climate

Passive strategies involving greenery significantly increase energy performance in buildings and comfortable microclimate conditions. However, few studies model and simulate their effect on buildings’ energy performance. Thus, this work assesses modelling approaches for conducting building performance simulations where detached vertical green trellises (DVGT) are included. The DVGT characteristics are modelled by: (i) large solid component blocks and (ii) small opaque solid component blocks to form a grid. A building with glazed façades is evaluated through dynamic simulation under the tropical climate of Panama City, using DesignBuilder. Parametric analysis is performed to study the impact of the trellis configuration on the performance in reducing the annual cooling, lighting, and total electricity consumption. A cost-effective evaluation is also conducted based on the net present value for each trellis configuration. Results showed strong agreement with previous studies reporting significant cooling needs reduction while increasing lighting needs and promising return periods. This concludes that the correct optical and radiative properties of the vegetation layer that are wanted to be modelled in a detached vertical trellis are crucial.

A Review of Data-Driven Methods in Building Retrofit and Performance Optimization: From the Perspective of Carbon Emission Reductions

In order to reduce the contribution of the building sector to global greenhouse gas emissions and climate change, it is important to improve the building performance through retrofits from the perspective of carbon emission reductions. Data-driven methods are now widely used in building retrofit research. To better apply data-driven techniques in low-carbon building retrofits, a better understanding is needed of the connections and interactions in optimization objectives and parameters, as well as optimization methods and tools. This paper provides a bibliometric analysis of selected 45 studies, summarizes current research hotspots in the field, discusses gaps to be filled, and proposes potential directions for future work. The results show that (1) the building-performance optimization (BPO) process established through physical simulation methods combines the site, retrofit variables, and carbon-related objectives, and the generated datasets are either directly processed using multi-objective optimization (MOO) algorithms or trained as a surrogate model and iteratively optimized using MOO methods. When a sufficient amount of data is available, data-driven methods can be used to develop mathematical models and use MOO methods for performance optimization from the perspective of building carbon emission reductions. (2) The benefits of retrofits are maximized by holistically taking environmental, economic, and social factors into account; from the perspectives of carbon emissions, costs, thermal comfort, and more, widely adopted strategies include improving the thermal performance of building envelopes, regulating HVAC systems, and utilizing renewable energy. (3) The optimization process based on data-driven methods, such as optimization algorithms and machine learning, apply mathematical models and methods for automatic iterative calculations and screen out the optimal solutions with computer assistance with high efficiency while ensuring accuracy. (4) Only 2.2% and 6.7% of the literature focus on the impacts of human behavior and climate change on building retrofits, respectively. In the future, it is necessary to give further consideration to user behaviors and long-term climate change in the retrofit process, in addition to improving the accuracy of optimization models and exploring the generalization and migration capabilities of surrogate models.

Pounding impact on seismic demands for adjacent irregular buildings with collinear alignment eccentricity

This research aims to evaluate the impact of pounding on seismic demands for neighboring irregular buildings with collinear alignment eccentricity and provide valuable recommendations for seismic design. To achieve this, a numerical simulation is conducted to calculate the effects of pounding on the seismic response requirements in different scenarios where two irregular adjacent buildings with eccentric center of mass are considered, plan irregularity is reflected with eccentricities between the rigidity center and mass center of the building’s superstructure. Adjacent buildings with three different heights involve four-, eight-, and twelve-story buildings with moment-resisting frame (MRF) structural system. To ensure reliable estimation of engineering seismic demands, three different ground motions, which are fully compatible with the design spectrum, are applied to different adjacent building configurations. A nonlinear time history analysis is performed to determine the response demands for different adjacent buildings with collinear alignment eccentricity, such as displacement, inter-story drift, story shear force, impact force, and acceleration responses. The Engineering Design Parameters (EDP) are thoroughly examined to gain a comprehensive understanding of the structural behavior and performance of the adjacent irregular buildings. The findings hold for all these scenarios, suggest that the colinear eccentricity of the irregular building in the closing/convergence direction, promotes the pounding and increases the number of impacts, while the eccentricity in the opening/divergence direction, reduces the pounding probability and the number of impacts between adjacent buildings. Moreover, the findings highlight the impact of eccentricity on peak acceleration responses and emphasize the importance of considering eccentricity in assessing the dynamic response of adjacent buildings with insufficient separation.

A review of complex window-glazing systems for building energy saving and daylight comfort: Glazing technologies and their building performance prediction

The increasing energy consumption and detrimental CO2 emissions contributing to global warming underscore the urgent necessity for energy conservation, especially within buildings. Among different building components, fenestration plays a pivotal role as it accounts for the majority of heat transfer across the building envelope. This emphasises the significance of window-glazing technologies in enhancing their thermal performance. Furthermore, window-glazing systems can lead to overheating issues, particularly in summer, and glare issues, especially in winter. These challenges have spurred the development of various advanced glazing systems. This paper provides a comprehensive review of these advanced glazing technologies based on their functionalities and working principles, with a focus on parameters such as U-value, solar heat gain coefficient and visible transmittance. Among these technologies, vacuum and aerogel glazing systems exhibit superior thermal insulation properties, with U-values below 1 W/m2 K, making them suitable for heating-dominated climates. Smart window systems, such as electrochromic windows, are ideal for cooling-dominated climates due to their low solar heat gain coefficient (0.09–0.47) and visible transmittance (0.02–0.62). Photovoltaic window systems not only provide effective thermal insulation and solar shading but also produce additional power for on-site use. Some of these glazing systems feature complex structures, which present challenges when integrating them into existing building simulation software to assess their impact on building performance. Therefore, this paper also examines techniques for conducting energy and daylight performance simulations for buildings that make use of complex window systems. Ultimately, the authors propose an approach to characterise the thermal, optical and electrical properties of a complex photovoltaic window system within existing building simulation software, such as EnergyPlus. This approach facilitates a thorough investigation into the effects of complex window systems on building energy efficiency and indoor comfort.

Implementing climate justice in Boston’s Building Performance Standard

Implementing climate justice in Boston’s Building Performance Standard

Operationalizing climate justice in the implementation of Boston’s Building Performance Standard

Operationalizing climate justice in the implementation of Boston’s Building Performance Standard

Configuration optimization and performance analysis of hybrid PV/wind systems in building groups

Distributed hybrid renewable energy is a promising technology for addressing environmental and energy issues, and its performance and system configuration play an essential role in the application. However, the contribution of energy sharing among buildings in building groups to the matching performance has yet to be fully explored. This study established a joint MATLAB-TRNSYS optimization model for the hybrid PV/wind building system to investigate the matching performance of energy consumption in building groups and energy production in PV/wind systems. The optimal system configuration for three objectives, technical, economic, and environmental, was also studied using the multi-objective particle swarm algorithm. Several factors influencing system performance and configuration were considered: renewable energy hybrid, a hybrid of different buildings, intensity of energy use and energy resource, and economic parameters. The results reveal that a hybrid system outperforms a single system, particularly a PV system with a smaller roof area and less installed capacity. Additionally, wind turbines contribute more to system performance than PV panels. Mixing buildings with different heights and functions could also improve system performance by renewable energy sharing in most instances, except multi-story office buildings. Increasing wind resources improves system performance more than solar resources, and increasing energy use intensity negatively impacts system performance for residential buildings but is beneficial for office buildings. Higher grid prices and feed-in tariffs can bring more economic benefits. This study revealed the contribution of energy sharing among different buildings, which could support better application of distributed hybrid renewable energy systems in complex urban environments.

Seismic Performance of Reinforced Concrete Frames on Sloped Ground Using Non-Linear Static Pushover Analysis

Nepal, renowned for its majestic Himalayan Ranges, is also highly vulnerable to seismic activity. Buildings on hill slopes often endure more significant damage during earthquakes than those on flat terrain. Traditional seismic analyses of buildings typically employ linear-static and dynamic methods, which might not fully represent the building's behavior under actual seismic conditions. This research addresses this gap by assessing the seismic performance of buildings on hill slopes using non-linear static analysis techniques. Specifically, the study evaluates the seismic response of 5-story buildings with stepback and stepback-setback configurations on slopes of 15°, 30°, and 45°. This evaluation is conducted through non-linear static analysis, also known as Pushover Analysis, using ETABSv20 software. Key performance metrics analyzed include the building's period, topstorey displacement, and base shear. The findings reveal that buildings with stepbacksetback configurations demonstrate superior seismic performance on the sloping ground compared to those with stepback configurations. This study underscores the importance of employing non-linear analysis methods to better understand and improve seismic resilience in hilly terrains.

Leveraging drone technology for enhanced thermal performance analysis in sustainable architecture: a case study of GBI-certified buildings in Malaysia

ABSTRACT In recent years, the realm of architecture has witnessed a significant transformation marked by a notable surge in focus on sustainable practices and energy efficiency. Architects and engineers increasingly recognize the innovative role of thermal efficiency in enhancing building performance. Such recognition emphasizes the critical importance of thermal analysis in understanding the thermal attributes of building materials and structures. Against this backdrop, this paper aims to bridge a current gap in architectural practices and sustainable design within the Malaysian context. It proposes a case study leveraging drone thermal mapping techniques on Green Building Index (GBI)-certified buildings. The study seeks to examine how architectural designs interact with environmental conditions and identify areas for improvement in sustainable building practices, particularly within Malaysia’s tropical climate context. The primary objective is to assess the effectiveness of drone technology in analysing building thermal performance and to explore how the findings can inform design interventions to enhance sustainability. To achieve this, a structured methodology comprising five procedural phases is employed in a case study focused on three iconic GBI-certified buildings in Putrajaya, namely Putrajaya Holdings Tower, Energy Commission Building, and Heriot-Watt University Malaysia. By integrating thermal imaging with visuospatial data and 3D modeling techniques, the study demonstrates the effectiveness of drones in analysing heat patterns, highlighting their potential as a tool for strategic design interventions. As an exploratory study, this paper serves as a catalyst for further investigations into the integration of drone technologies with architectural design, particularly within the context of tropical climates.

Energy performance certificate calculation methodologies across Europe and accommodating new performance indicators

Energy Performance Certificates (EPC) are used across Europe to communicate the energy performance of buildings to a range of different end users. However, as new approaches are introduced and guided at the European level via the Energy Performance Buildings Directive (EPBD), the ability of assessment methodologies and assessors to accommodate these new forms is likely to differ due to the significantly different frameworks in each country. The Horizon-funded crossCert project investigates this by identifying how EPC methodologies differ across countries, highlighting the implications of these differences on the performance gap and what that means for future innovations. Results indicate that methodologies vary considerably regarding general approaches, from highly standardised to highly tailored and assessor qualifications. This paper will look at such differences and investigate how these differences can affect future efforts towards improving EPCs.

Hydrothermal and mechanical performance of mortars containing waste brick powder

It is widely recognised that green building, environmental sustainability, and technical performance have recently become requirements in the field of civil engineering. For this reason, the new trend in research is to focus on the recycling and recovery of materials, even if some of them such as industrial waste are still underexplored. In this perspective, the main objective of this work is to study the influence of brick powder on the thermophysical and mechanical properties of mortars containing this type of waste, in different environments, and within the temperature range between ambient temperature and 50 °C. To this end, a number of mortar mixtures, in which cement was replaced by brick powder in different proportions, were studied and characterised according to technical standards in order to define the optimal substitution percentage. Three batches of samples were examined at different ages, i.e., 3, 7, 28, and 90 days. The samples of the first batch were kept in water at a temperature of 20 ± 2 °C with a relative humidity RH = 100 %, while those of the second batch were immersed and stored in water at 50 °C in order to simulate a hot and humid climate. As for the samples of the third batch, they were kept in a dry oven at 50 °C in order to investigate the effect of the hot and dry climate. The results obtained revealed that the partial replacement of cement by brick powder makes it possible to improve the thermal insulation characteristics but reduce the mechanical strength of the mortar. In addition, it was shown that in a hot and dry environment, the mechanical characteristics of the different mortars decrease as the rate of weight substitution of cement by brick powder rises. However, in a hot and humid environment, a reverse trend is observed. The findings also suggested that the optimal recommended rate of substitution of cement by brick powder is 20 %.

Experimental investigation on seismic performance of a super high-rise mega frame-double core tube composite structure

Increasing population density and urbanization have intensified the need for high-rise buildings in recent years. The seismic resistance of high-rise buildings should be carefully concerned in seismic regions, especially for super high-rise buildings which are most vulnerable to long-period earthquakes. This paper introduced the model design of a 499 m super high-rise mega frame-double core tube composite structure and presented the shaking table test results of the 1/50 scaled structural model. This super high-rise building possesses many conducive merits to resist seismic hazard, including steel reinforced concrete members, high-strength concrete and double core tube. In the test, there were three groups of long-period earthquakes and four incremental seismic intensity levels considered. The test phenomena indicated that the coupling beams of exterior tube were the first line of defense to resist seismic actions. The existence of inner tube improved the shear resistance of this building and there was no observed shear damage on the walls. Based on the instrumented data, the vibration characteristics, acceleration, displacement and strain responses of the structure were reported. The seismic performance of this super high-rise building meets the requirements of design specifications and its collapse resistance capacity is physically proved under severe earthquakes. However, the whiplash effect of acceleration is serious on the roof due to the reduction of mass and constraint for the mega column end. Furthermore, the inter-story drifts and strain responses of trusses in the top region are significantly larger. For the seismic measurement, great attentions should be paid to the exterior coupling beams and structural members in the top region of this super high-rise building. The presented work provides well experimental confirmation and reference for super high-rise buildings with mega frame-double core tube composite system.

Quantifying and Rating the Energy Resilience Performance of Buildings Integrated with Renewables in the Nordics under Typical and Extreme Climatic Conditions

The future buildings and society need to be resilient. This article aims to propose a novel concept of the energy resilience framework and implement a color-based rating system to quantify and rate the energy resilience performance of buildings in Nordic climates. The objective is to conduct a comparative analysis between old (1970s) and new (2020s) single-family buildings integrated with renewable energy sources and storage, assessing their energy resilience performance for heating during power outages, under extreme and typical climatic conditions. The study utilizes dynamic simulation of the buildings and renewable energy systems, conducting parametric studies to calculate proposed resilience indicators and rate their resilience performance, employing both passive and active methods. The total costs of the design variables are also calculated for economic evaluation. Given the complexities arising from climate change, the article uses a simplified method to synthesize regional climate to consider extreme climate change impacts on energy resilience performance. For the old building lacking PV, the robustness duration increased from 1 h to 3 h, and the degree of disruption (DoD) varied from 0.545 to 0.3 in extreme cold to warm climate scenarios, with the higher DoD number indicating worse performance. The impact of the season within the same climate scenario is also evident, as the habitability and robustness durations increased during spring compared to winter. The resilience improved with PV and battery. The new building showed that the robustness duration increased from 3 to 15 h, habitability durations increased, and the DoD varied from 0.496 to 0.22 from extreme cold to warm climates without renewables and storage. With the integration of PV and battery, the new building was able to achieve a lower DoD and better performance with lower PV and battery capacity, compared to the old building. Furthermore, utilizing the color grading method (red to green), optimal technical solutions and corresponding design variables were identified for each building type and climate scenario that could support decision-making. The total cost of the optimal solutions varied, as new buildings required lower costs to reach optimal performance. However, for optimal resilience performance during extreme cold climate scenarios, higher costs are required for each building type. The proposed resilience framework, indicators, color grading system, and costing could potentially support improvements in building regulations, ensuring the development of optimally resilient buildings, particularly in the face of extreme climatic conditions.

Impact of Spatial Layout Design on Energy Consumption of Ice Rinks in Cold Regions

The differentiated physical environment requirements within the internal space of ice rinks in cold regions result in a complex heat exchange process, which becomes the primary cause of high energy consumption. Therefore, analyzing the impact mechanisms of spatial layout parameters on the energy consumption of ice rinks is crucial during the early design stages. This study employed the Delphi method to identify the key parameters affecting the total energy consumption of ice rinks. It conducted single-factor experiments using building performance simulations to quantify the relationship between each layout parameter and the energy consumption. Based on the single-factor experiment results, orthogonal experiments were conducted to develop an energy-efficient spatial layout combination. The study indicates that the height-to-width ratio and the mixed area width are the most significant parameters. By adjusting the values of these parameters, the total energy consumption can be reduced by approximately 18% to 31%. The spatial layout strategy for ice rinks in cold regions proposed in this study will help architects make more effective decisions during the early design stages.

Increased Understanding of Building Operational Performance Through Occupant-Centric Key Performance Indicators

This article introduces a novel framework for Occupant-Centric Key Performance Indicators (OC KPIs) which aims to increase the understanding of building performance by aligning with occupant presence during the operational phase. Unlike traditional Key Performance Indicators (KPIs), OC KPIs can better emphasize the usefulness of energy use in the building to provide services and indoor comfort to occupants when they are actually present. Within this framework, the study explores 52 traditional KPIs and OC KPIs focusing on heating use, electricity use, domestic hot and cold water use, thermal comfort, and air quality. The study case is a multi-story residential low-energy building located in Denmark (five apartments, 16 rooms). The findings suggest that incorporating occupancy data in the OC KPI calculations enables a deeper understanding of energy-related occupant behavior and Indoor Environmental Quality (IEQ). These include 1) the potential for installing a more advanced heating control algorithm by analyzing occupancy over time in relation to heating use, and 2) the identification of significant appliance-related behavior in correspondence with load matching, which can be used for predictive maintenance or personalized energy use feedback. Furthermore, OC KPIs show the potential to help detect insufficient IEQ, energy use inefficiencies due to system anomalies/faults and/or occupant behavior, and guide towards savings opportunities. Finally, this article discusses the practical implementation of OC KPIs, and compares the latter with traditional KPIs, thus supporting a paradigm shift towards a more occupant-centric assessment of building performance.

A comparative study of dynamic performance the shear-wall and bracing shapes on the tall building in seismic area

The solution to overcome earthquake loads in the seismic regions is to use resisting systems such as shear walls and braces. It can be used as an alternative design for resisting systems of tall buildings. The main purpose of this research is to compare the performance of tall buildings with resisting systems of partial shear walls and a variety of brace shapes in the seismic area of Malang City, Indonesia, by using the partial shear wall against braces of reinforced concrete in the shapes of V, inverted V (Ʌ) and X (on two floors). The mechanical properties of the materials utilized in the models are determined from laboratory testing results. They consist of 30 MPa compressive strength concrete, 250 MPa yield strength steel, and 410 MPa ultimate strength steel. To overcome the lack of bracing, position the braces on the outer side of the building and the number resisting. The several outputs reviewed are stiffness, displacement, drift, ductility, vibration period, and natural frequency. In this study, structural analysis using SAP 2000 v.20 software is used in the four models of the eight-story existing structure in Malang City. The results showed that the inverted V (Ʌ) reinforced concrete brace is the most suitable design as an alternative design for the building, compared to the partial shear wall and the other bracing shapes. The results of the study that in the X-direction the stiffness, displacement, drift, ductility, vibration period, and natural frequency respectively as follows 4.92865E+12 N/mm, 144.53 mm, 127.73 mm, 0.339, 1.12 s and 0.893 Hz. Whereas the displacement and drift in the Y-direction are 127.97 mm and 113.63mm. For practical implication, using a fully shear wall and the inverted V(Ʌ) brace creates a better performance of the structure in seismic areas.

Advances in building data management for building performance standards using the SEED platform

Reducing energy consumption and greenhouse gas emissions in the built environment is a critical step in achieving emission goals to mitigate climate change impacts. Local, federal, and international jurisdictions are deploying several methods to reduce energy and emissions such as voluntary and mandatory benchmarking and building performance standards, requiring building owners to reach energy and emission targets.Jurisdictions leveraging benchmarking and building performance standards require knowledge of the buildings covered; which is a large task due to staffing constraints, limited information on building characteristics and tax parcel data, and the need for advanced data management techniques to align datasets. This paper describes an open-source platform's recent advances to create consistent taxonomies, identify erroneous data, enable auditability, and track building performance. The paper concludes with two use cases on how the platform has been used by jurisdictions.

The environmental performance of zero-emission buildings in a fossil-free energy system

Buildings can play an important role in reducing GHG emissions through increased energy efficiency. The European Commission mandates that all new buildings should be “zero emission buildings” (ZEB), aiming at a zero GHG emission building stock by 2050. The extent to which ZEB can contribute to reduced GHG emissions, however, varies between countries, due to different energy systems. It is also important to consider other environmental effects to avoid that climate benefits come with unintended consequences. Here, we explore the life-cycle environmental performance for a ZEB in a case where electricity and heating are largely fossil-free. The assessment concentrates on i) environmental impact of the use stage in relation to the product stage, ii) the interrelation between different energy sources, with focus on household electricity, and iii) the performance for more impact categories than primary energy use and climate change. While our results generally support the use of ZEBs from an environmental perspective, they also show that the climate benefit in this setting is marginal. However, given that energy systems are connected and energy savings in one place can reduce the demand for fossil energy elsewhere, the climate benefit of ZEBs is likely underestimated. Besides methodological implications for future studies, this indicates that current EU policy is promising, as incentives for implementation of ZEBs are unaffected by domestic effects.

Comparative study of optimization methods for building energy consumption and daylighting performance

When striving for sustainable development, designers encounter the formidable task of integrating the advantages of daylighting into energy-efficient designs. The process of investigating a multitude of design variables can be arduous and time-intensive. However, computational simulations provide indispensable insights into forecasting performance. A considerable number of these design challenges do not have explicit mathematical solutions; thus, black-box optimization techniques are favored for the purpose of determining the most effective design solutions. Popular meta-heuristic optimization algorithms, including the Genetic Algorithm (GA), Particle Swarm Optimization (PSO), Whale Optimization Algorithm (WOA), Sine Cosine Algorithm (SCA), Grey Wolf Optimizer (GWO), Ant Lion Optimizer (ALO), and Multi-Verse Optimizer (MVO), are described and thoroughly analyzed in this article. In addition, the present study run empirical studies to compare these optimization algorithms by applying them to tackle five distinct daylighting and energy optimization problems associated with enhancing building performance. In the test cases, the present study results demonstrate that the PSO and MVO algorithms exhibit better performance compared to the GA and WOA algorithms. The selection of the most suitable algorithm is contingent upon the distinctive attributes of the problem, and the intricacy of the optimization landscape.