Commercial Office Buildings Research Articles

BUILDING ENVELOPE RETROFIT FOR ENERGY SAVINGS IN MALAYSIAN GOVERNMENT HIGH-RISE OFFICES: A CALIBRATED ENERGY SIMULATION

With over a third of global energy used for building construction and operation, an optimum design for building envelopes is essential to improve the energy performance of the existing buildings. This study revealed that typical government high-rise office buildings in Malaysia have an average Building Energy Intensity (BEI) of 161 kWh/m2/year before any upgrading works on the air-conditioning and mechanical ventilation (ACMV) systems were conducted. This value is higher than the recommended value in Green Building Index (GBI) for commercial office buildings (150 kWh/m2/year) and the Economic Planning Unit (EPU) standard for public buildings (140 kWh/m2/year). Therefore, this study employed a case study approach combined with calibrated computer simulation to determine the optimal building envelope retrofit strategies and identify the three levels of interventions (minor, moderate and major levels) with corresponding energy reduction. A validated model representing a typical existing government high-rise office building in Malaysia was chosen as the base case model for energy evaluation studies. The effectiveness of each level of intervention and its energy retrofit measures (ERMs) were evaluated compared to the actual electricity bills. The results showed that all levels of interventions provided between 4% to 7% savings in annual energy consumption. The proposed interventions demonstrated compliance with the BEI benchmark margins of the GBI and EPU standard, namely 116 kWh/m2/year (minor intervention level), 113 kWh/m2/year (moderate intervention level), and 110 kWh/m2/year (major intervention level).

It's not just technical - Socio-technical challenges to the efficient operation of commercial office buildings

Facility management companies are the primary agents that mediate between building systems and users. As such, the impact of the socio-technical aspects within facility management companies can play a central role in operational energy management. In this study, we conducted and analyzed individual interviews with 11 building management professionals across two facility management companies. Participants included management, energy analysts, and building operator personnel, collectively working on eight commercial office buildings. Our interviews aimed to answer three research questions: (1) How is improving OE viewed, prioritized, and incentivized within the two FM organizations? (2) How are the current building settings and sequences of operations determined and documented by these FM companies? (3) What tools are used by these FM companies to analyze energy when making operational decisions? Using the results from our interviews and existing challenges identified in the literature, we identify nine primary challenges faced by these organizations and provide nine recommendations aimed at the industry. The recommendations cover organizational challenges, contracts with outside stakeholders, implementing sensors and tools, and the development of future tools. The diversity of the recommendations highlights the need for socio-technical analysis of facilities management companies and contributes to a growing body of this type of research.

RAID: Robust and Interpretable Daily Peak Load Forecasting via Multiple Deep Neural Networks and Shapley Values

Accurate daily peak load forecasting (DPLF) is crucial for informed decision-making in energy management. Deep neural networks (DNNs) are particularly apt for DPLF because they can analyze multiple factors, such as timestamps, weather conditions, and historical electric loads. Interpretability of machine learning models is essential for ensuring stakeholders understand and trust the decision-making process. We proposed the RAID (robust and interpretable DPLF) model, which enhances DPLF accuracy by recognizing daily peak load patterns and building separate DNN models for each day of the week. This approach was accessible for energy providers with limited computational resources, as the DNN models could be configured without a graphics processing unit (GPU). We utilized scikit-learn’s MLPRegressor for streamlined implementation, Optuna for hyperparameter optimization, and the Shapley additive explanations (SHAP) method to ensure interpretability. Applied to a dataset from two commercial office buildings in Richland, Washington, RAID outperformed existing methods like recurrent neural networks, Cubist, and HYTREM, achieving the lowest mean absolute percentage error values: 14.67% for Building 1 and 12.74% for Building 2. The kernel SHAP method revealed the influence of the previous day’s peak load and temperature-related variables on the prediction. The RAID model substantially improved energy management through enhanced DPLF accuracy, outperforming competing methods, providing a GPU-free configuration, and ensuring interpretable decision-making, with the potential to influence energy providers’ choices and promote overall energy system sustainability.

ANALYTICAL MODEL OF THE T- STUB COMPONENT IN THE END-PLATE BOLTED CONNECTION OF THE BEAM TO THE COLUMN IN TENSION

End plated connections of metal structures are quite relevant and are usually used in office, commercial, and commercial-office buildings. It is very important to be able to diagnose the real general behavior of beam-to-column connections based on their geometric and mechanical properties. Therefore, the analysis of steel structures at the modern level requires a specialist to have a thorough understanding of their work, as well as the calculation provisions laid down in current design codes. In contrast to Eurocode 3 design codes, the current Ukrainian state building regulations do not contain clear instructions on the beam to column joint calculation and do not even give a clear definition of the concept of steel joint and steel connection. It should be noted that the beam to column connection is the most responsible area that requires special attention, as it significantly affects the design scheme of the structure, as well as its economic efficiency. By using the semi-rigid connection concept, weight savings of up to 20% can be achieved. In the presented article, a simplified mathematical model of the t-stub component of the tensile zone of the semi-rigid bolted connection of the beam to the column was developed using the component method. In the given solution of the connection in the tension zone, the following components were distinguished: the flange in bending, the end of the column in bending, and the bolts in tension. All these elements were modeled from two t- stub components connected through an end plate with the help of bolts. A design scheme for determining the stress-strain state was proposed. The analysis of the exhaustion of the bearing capacity of the t- stub component was performed according to three scenarios depending on the size of its individual elements (end plate thickness, bolt diameter). The obtained results will make it possible to determine the bearing capacity with possible variations of the transition to the limit state, as well as to estimate the deformations of the considered component of the connection. Keywords: end-plate connection, mathematical model, T-stub component, bolt connection.

Deploying data driven applications in smart buildings: Overcoming the initial onboarding barrier using machine learning

The introduction of smart building technology promises many operational and productivity benefits and enables smart grid integration. A significant barrier to deploying smart building applications is mapping the building sensor metadata to the requirements of the smart building applications. In this paper, we have studied the problem of weakly supervised machine learning to accelerate the metadata mapping process, and demonstrated that weak supervision is a promising approach, which to the best of our knowledge, has not been studied in this context. We developed a pattern-based workflow that enables subject matter experts to craft simple rules that process the idiosyncratic text found in building sensor metadata. Our method was validated using three medium-sized commercial office buildings and a public dataset. We worked closely with a team of commercial building subject matter experts to develop and validate our workflow. We compared our approach to active learning and discovered that weak supervision appears to scale better with building size. Subject matter experts overwhelmingly preferred this approach compared to manual methods, and our study with three buildings shows that weak supervision can reduce the time to annotate the metadata in building systems by a factor of 4.

Reclaimed water systems in office buildings: Perceptions of building facilities managers

AbstractBy the year 2050, 67% of the global population will be living in cities where water demand is projected to outstrip supply. This shortage calls for identifying ways through which urban residents and commercial interests can adapt to water stress. As commercial buildings contribute significantly to water consumption in cities, building facilities managers (BFMs) have a significant role in formulation and implementation of the adaptation approaches. Their perceptions of alternative water sources, including reclaimed water, are, therefore, important. In this study, the perceptions of 40 BFMs on reclaimed water use in buildings were analyzed using Q‐methodology. Analysis correlated the responses of different people, factoring out the groups of people who hold similar viewpoints. Results showed that participants could be categorized under four factors. Participants in Factor 1 perceived reclaimed water as being healthy and a worthy investment. Those in Factor 2, however, had negative perceptions and did not trust local governments to appropriately manage the treatment process, thus presenting health concerns. They also found reclaimed water repulsive. Participants in Factor 3 were also less willing to adopt reclaimed water, but felt that its use for non‐potable purposes would be acceptable. The final group, those in Factor 4 focused more on the cost efficiency and sustainability of reclaimed water, finding it acceptable on those grounds. However, they thought that decisions on its use should be the building owners' prerogative rather than the BFMs. The implications of these findings with respect to encouraging reclaimed water use in commercial office buildings are discussed.

ANALYSIS OF NEW RETAIL LOCATION BASED ON GIS SPATIAL ANALYSIS—TAKE STARBUCKS AND LUCKIN COFFEE FOR EXAMPLE

Abstract. This paper selects nine administrative districts in Shenyang, and compares the spatial distribution patterns and factors influencing the location of the new retail brand Luckin Coffee and the classic traditional retail brand Starbucks in Shenyang. The results show that the traditional retail Starbucks tends to be distributed in a single-center pattern, while the new retail brand Luckin Coffee tends to be distributed in a multi-center decentralized pattern. According to the significance of the influence on spatial layout, the most important factor influencing the location of traditional retail Starbucks Coffee is the density of commercial plazas, while the most important factor influencing the location of new retail brand Luckin Coffee is the density of commercial office buildings. The new retail brand Luckin Coffee, with its Internet gene, weakens the spatial resistance of its store location.

Orchestrating energy transitions: from ‘eco-bling’ to tuning the building

ABSTRACT Through their material construction and energy-consumption practices, buildings are deeply implicated in carbon-intensive energy systems, and important sites of energy transitions. Contributing to work that has highlighted the ways social practices and cultural meanings shape energy consumption, we examine energy management in commercial office buildings and its prospects for clean energy transitions. Through a case study of commercial office buildings in the CBDs of Sydney and Melbourne, Australia, we contrast the emphasis on shifting building energy consumption through large-scale technological interventions in the urban fabric with the unheralded potential of quotidian ‘building tuning’. At this scale, energy transitions are enacted through everyday and episodic practices of upgrading, maintenance and repair that remain largely invisible, though highly effective and nimble. The paper reveals how ‘tuning’ assembles diverse technologies, knowledges, skills and practices, to simultaneously cohere the building and foster building energy transitions. Our argument is that routine socio-technical work of maintenance, repair and upgrading not only holds the building assemblage together but underpins incremental energy transition. This opens out both the geographies and temporalities of urban energy transitions to capture the unheralded capacity of small-scale, routine interventions and the varied temporalities at which energy transitions operate.

Economical viability analysis of an innovative gravity‐driven rainwater harvesting system for a commercial office building

AbstractGravity‐driven rainwater harvesting (RWH) system showcases a promising alternative solution to reduce energy consumption in rainwater recycling. However, the economic efficiency is one of the most concerns with regard to the adoption of this green infrastructure. In this study, a commercial official building has a rooftop area of 1600 m2 and with 560 inhabitants was assumed to apply two configurations of RWH system (i.e., gravity system and pressure system), and comparative study was conducted to evaluate the economic performance of two RWH systems. The potential water saving quantity of the RWH system was simulated based on a daily water balance model and their expected economic efficiency were discussed in terms of benefit cost ratio and net present value. Results shown that only when the building height is higher than 102 m or the property rent is less than 0.4 CNY (China Yuan) per square metre per day, can make the gravity system economically attractive. This study provides an innovative approach to utilize roof rainwater in a more low‐energy mode; it is of great significance to promote building energy‐saving and carbon reduction.

Controlling electricity storage to balance electricity costs and greenhouse gas emissions in buildings

The optimal management of flexible loads and generation sources such as battery storage systems in buildings is often concerned with minimizing electricity costs. There is an increasing need to managed flexible resources in a way that minimises both costs and carbon emissions. Minimising emissions of grid consumed electricity requires quantification of the carbon emissions intensity of the electricity grid, so first we develop a real-time emission intensity model of the Australian National Energy Market using a power-flow tracing approach. This model reveals that electricity price signals currently do not drive consumers toward using electricity at times of lower emissions. For example, the mean and peak emissions intensity during low electricity tariff periods are the same or slightly higher than those during high tariff periods, while the 30-min wholesale electricity price in each region has no significant correlation with the emissions intensity of electricity consumed in that region. The emissions model is then used to investigate the extent to which controlling a battery storage system to minimise costs under existing electricity tariff structures also leads to minimisation of greenhouse gas emissions for a case study commercial office building. Results show that reducing emissions does indeed come at the expense of increasing costs. For example, annual operating cost savings reduced from 31% to 20% when the battery control was changed from minimising costs to minimising emissions. This has important implications for buildings seeking to reduce emissions as well as for the design of electricity tariffs.

Green Building Contractors 2025: Analyzing and Forecasting Green Building Contractors’ Market Trends in the US

With population growth, the demand for building construction is continuously increasing. This comes at the price of the built environment where the building sector is contributing to large energy consumption and carbon footprint releases. To encourage sustainable construction, contractors need to see the market benefit of “going green”. Previous studies of green building contractors (GBCs) mainly relied on qualitative discussions and lacked studying the market performance which drives contractors’ decisions the most. This paper collects GBC revenue data from the Engineering News-Record magazine for the top 100 GBCs over a 13-year period and performs trend analysis to assess the market performance of GBCs and time series analysis to forecast future revenues. In addition, k-means clustering technique was used to divide the firms into subsets of similar behavior to understand growth trends for different firm sizes. The results show a continuous increase in green building revenues (GBRs), where commercial office buildings contribute the most to it. Furthermore, the firm ranks responsible for most of the growth are identified; mainly the top 9. Predictions show the expected steady increase in GBR in the upcoming years which is anticipated to reach 83 billion USD in 2025. The findings inform contractors considering executing green buildings by understanding the market trends and forecasted revenues. Moreover, contractors who are already in the green building business can use this information to increase their revenues in their respective market subset.

Evaluation of Property Investment (Case of Buy or Build Commercial Office Building in Jakarta’s CBD Area)

Financial security plays an important role in the company’s sustainability. Property is one of the financial security mediums and at the same time also as the investment medium. Not only the medium but also the investment destination is very influential in the result. Therefore, Jakarta as the capital city of Indonesia and as the centre of economic activity has a very big potential market. Jakarta is divided into 5 administrative cities, and CBD as the prime area is located in the golden triangle of Jakarta specifically in South Jakarta. BPG Corporation is one of the companies based in Jakarta, with the intention to strengthen its financial security. The company assesses by the valuation to investing in a property sector, which faces two choices whether to buy or to build from the ground. This study will use the Discounted Cash Flow method as the valuation tool to predict the risks, advantages, and weaknesses of the company’s financials. The result is that the buy option is more beneficial to the company with current available equity. IRR of the buy option has ranged from 8% to 13% and the NPV indicates also positive figures.

Waste Characterization Study of Pre-Covid-19 Commercial Office Buildings

This study examines the average commercial office waste profile by region and by program type. The regions included in this study, including New York, the Mid Atlantic, California and others, had different recycling/composting program mandates. Within regions, building waste diversion programs differed as well. The results of the review reflect some differences in the success of the diversion programs utilized: single stream recycling, multi stream recycling and with or without organics programs. Over 100 waste audit results were compiled representing commercial office waste prior to the changes in the commercial real estate and waste industries during the COVID 19 pandemic.

Assessment of the overall energy performance of an SPD smart window in a hot desert climate

In this study, the overall energy consumption and visual comfort of a switchable suspended particle device (SPD) smart window were investigated as part of the glazing integration of an adaptive building designed to consume less energy in a hot desert climate. A typical floor of a commercial office building in Riyadh was chosen for the energy and visual comfort simulation, which was based on Energy-Plus and Diva-for-Rhino software for cardinal orientation. A comprehensive simulation analysis of various state of SPD glazing, namely opaque (OFF), transparent (ON) and automated controlled (based on solar radiance: from 100w/m2 – 900w/m2), was conducted and the results were compared against traditional single glazing and double-glazing low emissivity (DG low-e) coated windows for reference. The simulation results indicated that switchable SPD smart windows (in the OFF and automated states) achieved a promising reduction of net energy by up to 58% against DG low-e, apart from at the northern orientation. Conversely, the opaque (OFF state) had a counterproductive impact on lighting energy consumption and visual comfort. Acceptable daylight autonomy (DA300lux) and Useful daylight illuminance (UDI100lux–2000lux) was observed for the SPD smart window in the ON and automated controlled states; moreover, it offered a significant reduction in daylight glare probability (DGP). Thus, controlled switchable SPD glazing can be a good alternative to standard glazing in a hot desert climate in terms of reducing energy use and providing visual comfort.

Future climate scenarios and their impact on heating, ventilation and air-conditioning system design and performance for commercial buildings for 2050

Designers of commercial building's heating, ventilation and air-conditioning (HVAC) systems use typical weather data adjusted with global climate models (known as “morphing”) to obtain data reflecting climate change. Previous studies have found that climate change will increase annual cooling energy by 27–47% and peak cooling demand between 28 and 59% by 2070, but have not explored 2050 timeframes, extreme weather scenarios, nor examined thermal comfort beyond degree-day assessments. This study investigates the use of extreme weather datasets in HVAC building simulation to assess traditional HVAC system sizing methods under extreme conditions, as climate change will lead to more severe and frequent extreme weather events. This study also aims to quantify the impact of climate change on energy use, peak demand, and thermal comfort for a typical commercial building in the four most-populated Köppen-Geiger climates. A typical commercial office building was modelled in OpenStudio using Energy-Plus Weather (EPW) datasets using eight extreme weather scenarios constructed from historic weather data for each climate. Two downscaling morphing methodologies were used to prepare future weather datasets for 2050. The results show datasets with higher variability increase peak cooling demand up to 35% and unmet cooling hours up to 189%, a significant increase over a shorter timeframe than previously reported. A methodology to include extreme hot and cold weather conditions and datasets, in addition to typical conditions, is proposed to future-proof HVAC system design against the impacts of climate change across the most populated global climates.

Reckoning with Reality: Reflections on a Place-Based Social Innovation Lab

This is a reflection upon a social innovation lab process used to establish and build an ongoing culture of sustainability (COS) within a new multi-tenant commercial office building. It seeks to answer two key questions: (1) what are the design tensions that emerge when constructing co-design processes meant to encourage social innovation in a complex system while working from inside that complex system; (2) in building commons governance structures in a complex system, what are realistic expectations for the voluntary participation when multiple organizations with different core mandates are involved? This paper’s primary results come from reflecting upon the COS development coming from the social innovation lab process and adaptations process needed for it to work within a place-based context. The COS intervention itself is still in process and was disrupted by COVID-19, so these findings are still preliminary. Participatory co-design research often involves a great deal of complexity and tacit knowledge, so the key finding here is the surfacing of four core sources of tension that arise when developing a co-design process for the management of a commons: the allocation of costs for co-ordinating collective action, balancing a homogeneous platform for action with heterogeneous participants, physical building infrastructure and social co-design approaches, and between-tenant organization leadership and co-design approaches. This paper’s key contribution is in clarifying core challenges that participatory process designers face when developing and implementing co-design processes.

Over the weekend: Water stagnation and contaminant exceedances in a green office building

The role of water stagnation (~60 hours) in a 2-story commercial office building on building water quality was studied (January to February 2020) for three weekends. Chemical and biological parameters including pH, total chlorine, metals concentrations,Legionellaspp. and total cell count were analyzed to understand the differences in water quality at the building entry point, and at eleven fixtures within the building’s copper plumbing. Consistently, the total chlorine concentration decreased over the weekend (p< 0.05), was greatest at the building entry point (maximum 0.8 mg/L), and was lowest within the plumbing (maximum 0.28 mg/L). As expected, total cell count levels were much greater on Monday compared to Friday (p< 0.05) at every sampling point.Legionellaspp. was found to be highest at the fixture with no use recorded during sampling. Throughout the building, copper and lead levels increased over the weekend (p< 0.05). Copper exceedances above the federal health-based drinking water limit (1.3 mg/L) were localized to four fixtures, branched from the same riser, that shared a pattern of variable use. Flushing was conducted at one location with consistent copper exceedances but 54 minutes were required to reach the public water supply. Flushing was not a viable copper remediation method as it would need to be repeated every 19 hours or require discarding more than 50 gallons before use. No prior water testing was conducted in the buildings’ life. The results suggest that water quality varies significantly over the week. This has implications for water testing plans and interpretation of data collected from buildings.

A study of energy consumption for office buildings in Vietnam for sustainable energy and climate change mitigation

This study used survey data to evaluate the current status of electrical energy use of commercial office (CO) and governmental office (GO) buildings in Hanoi and Ho Chi Minh City (HCMC) in Vietnam. Main data used in the analyses including floor area and monthly electricity consumption which were gathered from the questionnaire survey for 57 CO and GO buildings in two cities – conducted by the Vietnam Clean Energy Program in 2015. The basic statistical analysis techniques were used to evaluate the electricity consumption intensity of office buildings and preliminarily analyze key factors affecting the energy consumption of these buildings. The results generally showed that CO buildings consumed significantly more electricity than GO buildings in all months of the year and the variation and trend of mean monthly electricity consumption intensity of the buildings strongly depend on that of ambient air temperature. In addition, the energy use intensities (EUIs) of CO buildings, GO buildings, and both buildings (CO+GO) in HCMC (in a hot climate all year round) were higher than those in Hanoi (in a climate with four distinct seasons). The mean EUIs of these buildings in Hanoi, HCMC, and both cities were 105.9, 116.4, and 109.6 kWh/m2 floor. year. The findings of this study are useful information on the status of energy use and energy efficiency of CO and GO buildings in Hanoi and HCMC, thereby contribute scientific bases to the development of policies and solutions to promote the energy efficiency of CO and GO buildings in the coming years and urgent actions for sustainable energy and climate change mitigation in Vietnam.

De-Risking the Energy Efficient Renovation of Commercial Office Buildings through Technical-Financial Risk Assessment

Energy efficiency in the building sector plays a key role in supporting European and global commitments against the current climate crisis. A massive adoption of deep renovation measures would allow a global reduction of energy need up to 36%, based on estimations. However, the market for building renovation is still limited, due to uncertainties associated with risk evaluation. This paper aims to suggest a method to evaluate the financial impacts of technical risks related to energy efficiency investments. Key performance indicators (KPIs) necessary to evaluate the investment risk associated with energy renovation have been defined based on an analysis of the correlation between technical and financial risks, and their originating factors or root causes. The evaluation has been carried out thanks to the EEnvest tool: a web-based search and match platform, developed within the EEnvest collaborative research project funded by the European Commission (EC). This evaluation methodology has then been applied to a case study, an office building located in Rome, for whom an energy efficient renovation project was already in place to reduce energy needs. The investment risk of the renovation project is calculated for two different scenarios: with and without risk mitigation measures being applied during the design, installation and operation phases. The results show the different technical and financial risk trends of these two scenarios, highlighting the benefits obtained by the implementation of mitigation measures.

Analysis of smart building solutions for optimizing the energy performance in a new commercial building

Contemporary commercial building?s demonstrate performance from a sustainability and environmental perspective. Usually, an appropriate energy performance is achieved using efficient mechanical systems, however, the operation method with smart control is significant in the overall energy consumption. The research follows a two-year design and construction process of a commercial building where the integration of smart technology was a mandatory requirement by the owner, alongside with the prerequisites of the LEED? green building certification. The goal was to design, build and optimize the performance of the new Innovation Campus commercial office building complex using smart building solutions. The research was performed with energy modelling and dynamic simulation until completion of the building, where the design and investment decisions were constantly evaluated. The new optimized building?s performance demonstrated 42% of annual energy reduction and 34% of cost reduction according to the ASHRAE 90.1 Appendix G baseline Benchmark building.