People or Systems: Does Productivity Enhancement Matter More than Energy Management in LEED Certified Buildings?

This study examines the impact of energy management and productivity-enhancing measures, implemented as part of LEED Existing Buildings Operations and Management (EBOM) certification, on source energy use intensity and rental premiums of office spaces using data on four major US markets. Energy management practices, comprised of commissioning and advanced metering, may reduce energy usage. Conversely, improving air quality and occupant comfort in an effort to increase worker productivity may in turn lead to higher overall energy consumption. The willingness to pay for these features in rental office buildings is hypothesised to depend not only on the extent to which productivity gains enhance the profits of a commercial tenant but also on the lease arrangements for passing any energy savings to the tenant. We apply a difference-in-differences method at a LEED EBOM certification group level and a multi-level modelling approach with a panel data structure. The results indicate that energy management and indoor environment practices have the expected effect on energy consumption as described above. However, the magnitude of the achieved rental premiums appears to be independent of the lease type.

Utilize BIM Technology for Achiveing Sustainable Passengers Terminal in Baghdad International Airport

The construction of airport infrastructures usually consumes huge amount of energy. In fact, the airport buildings are among the largest energy consumers entities due to their huge size and special operation pattern as well as their unique configuration that facilitate the large number of accommodated passengers. Despite the local energy shortage in Iraq in the last two decades, there is a quite scarce number of researches that deal with sustainable airport buildings. The aim of this research is to analyze the terminal building in Baghdad International Airport in order to find out the best set of modifications that result in an optimal energy consumption and least carbon dioxide emissions. The analysis was conducted by the use of Building Information Modelling (BIM) technology and the associated programs such as; Auto desk Revit 2021 and Auto desk Insight 360, in order to determine the optimal strategies by which the most applicable alternative construction materials and procedures are considered in order to obtain an environmentally and economically sustainable airport terminal buildings. By applying this analysis on Nineveh terminal building in Baghdad International Airport revealed that many alternatives are capable of making tangible reduction in the Energy Use Intensity (EUI). Such reductions are noticed when altering, in the optimum manner, the windows configurations in terms of size, glazing type, and shadings. The alteration of construction materials for walls and roofs also reduces the EUI. It was also found out that the change in lighting control systems and lighting efficiency may reduce EUI. But the major impact could be resulted when altering the Heating/Ventilating/ Air conditioning Systems (HVAC) in the optimum manner which reduces the EUI by 67.15kw/m2/year, and the proper use of photovoltaic panels which provides a sustainable electricity and reduces EUI by 57.08 kWh/m2/year. Accordingly; in the quest of the best procedure to develop a sustainable terminal building, it is highly recommended to alter the HVAC systems and the utilization of the photovoltaic panels on rooftops.

518 Late-Breaking: Effect of Feedlot Diets on Environmental Emissions from Four Representative U.S. Feedlots and the Beef Production System

Our objective was to evaluate effects of feedlot dietary management strategies on environmental impacts and net returns of feedlot operations in the United States. Representative feedlots were simulated with the Integrated Farm System Model (IFSM 4.6; USDA-ARS, University Park, PA) to quantify baseline environmental impacts of feedlot production and full US beef cattle production systems. The simulated dietary strategies included: 10% increase in feed efficiency, use of less water intensive forages, 10% increase in byproduct inclusion, 10% improvement in water use efficiency of corn, and steam-flaking of corn. Days on feed and head finished per year were held constant for all strategies to have equal comparisons to baseline results. Dietary management strategies were individually modeled and simulated in IFSM for each feedlot operation to obtain intensities (expressed per kg gain) for greenhouse gas (GHG) emissions, fossil energy use, blue water consumption, and reactive nitrogen loss. Feedlot operations were then linked with cow-calf, stocker, and backgrounding operations to estimate environmental intensities (expressed per kg CW) for full cattle production systems. Improving feed efficiency had the greatest effect on reducing carbon emission intensities (6%), energy use intensity (8%), blue water use intensity (9%), and reactive N loss intensity (4%) for feedlot operations. Increasing corn byproduct inclusion resulted in 9% reduction in blue water use intensity. However, byproduct inclusion increased reactive N loss intensity by 11% as a result of greater protein concentrations in the diet. Switching from rolled corn to steam flaked corn increased energy use intensity by 9%, but little to no changes (1% increase to 3% reduction) were observed for other environmental intensities. Improved feed efficiency was the most effective strategy to reduce environmental footprints of beef cattle production (1 to 2% reductions). Overall, feedlot dietary strategies were less pronounced for the full beef production system compared with feedlot results.

Passive design strategies for medium-format retail buildings in Toronto toward NZE Using Ecotect® Analysis 2011, with a case-study of a retail building in Toronto, ON

This paper studied passive design strategies available for medium-format retail buildings in Toronto. An existing retail building, designed by the researcher and built in 2014, was chosen as a case study. A framework of four models to show incremental improvements was created and multiple passive design strategies were applied to each model. The framework targeted four energy goals. Each goal represented a level of higher efficiency using Energy Use Intensity (EUI). Each of the four design models was simulated using Ecotect® and all results documented and analyzed. At the end of last model’s analysis, an architectural design project to exhibit design strategies was created. There are perhaps two significant points that the study has achieved. First point was the identification of key passive strategies that can be implemented in retail buildings in Toronto. The second was the methodology by which incremental improvements with pre-set energy targets can be followed with validated results.

Passive design strategies for medium-format retail buildings in Toronto toward NZE Using Ecotect® Analysis 2011, with a case-study of a retail building in Toronto, ON

This paper studied passive design strategies available for medium-format retail buildings in Toronto. An existing retail building, designed by the researcher and built in 2014, was chosen as a case study. A framework of four models to show incremental improvements was created and multiple passive design strategies were applied to each model. The framework targeted four energy goals. Each goal represented a level of higher efficiency using Energy Use Intensity (EUI). Each of the four design models was simulated using Ecotect® and all results documented and analyzed. At the end of last model’s analysis, an architectural design project to exhibit design strategies was created. There are perhaps two significant points that the study has achieved. First point was the identification of key passive strategies that can be implemented in retail buildings in Toronto. The second was the methodology by which incremental improvements with pre-set energy targets can be followed with validated results.

Measuring social equity in urban energy use and interventions using fine-scale data

Cities seek nuanced understanding of intraurban inequality in energy use, addressing both income and race, to inform equitable investment in climate actions. However, nationwide energy consumption surveys are limited (<6,000 samples in the United States), and utility-provided data are highly aggregated. Limited prior analyses suggest disparity in energy use intensity (EUI) by income is ∼25%, while racial disparities are not quantified nor unpacked from income. This paper, using new empirical fine spatial scale data covering all 200,000 households in two US cities, along with separating temperature-sensitive EUI, reveals intraurban EUI disparities up to a factor of five greater than previously known. We find 1) annual EUI disparity ratios of 1.27 and 1.66, comparing lowest- versus highest-income block groups (i.e., 27 and 66% higher), while previous literature indicated only ∼25% difference; 2) a racial effect distinct from income, wherein non-White block groups (highest quintile non-White percentage) in the lowest-income stratum reported up to a further ∼40% higher annual EUI than less diverse block groups, providing an empirical estimate of racial disparities; 3) separating temperature-sensitive EUI unmasked larger disparities, with heating–cooling electricity EUI of lowest-income block groups up to 2.67 times (167% greater) that of highest income, and high racial disparity within lowest-income strata wherein high non-White (>75%) population block groups report EUI up to 2.56 times (156% larger) that of majority White block groups; and 4) spatial scales of data aggregation impact inequality measures. Quadrant analyses are developed to guide spatial prioritization of energy investment for carbon mitigation and equity. These methods are potentially translatable to other cities and utilities.

The importance of understanding occupant behaviour in buildings: exploring the nexus of design, management, behaviour, and energy use in green, high-rise residential buildings

The quest to ‘green’ the built environment has been ongoing since the early 1970s and has intensified as the threat of exceeding 450 ppm of atmospheric carbon dioxide has become more real. As a result of this, many contemporary residential high-rise buildings are designed with hopes of achieving carbon emission reductions, while not sacrificing occupant satisfaction, or property value. Little is known about how the occupants of these buildings contribute to the energy and water consumed therein, nor the effects that these design aspirations have on occupant satisfaction. The present study relies on data collected in four recently built, Leadership in Energy and Environmental Design [LEED] certified, high-rise, residential buildings in Ontario, Canada. Using various sources of data (i.e., from energy and water submeters, questionnaire responses, interviews, and physical data relating to each suite) the extent to which physical, behavioural, and demographic variables explain suite-level energy and water consumption was explored. Energy use intensity differed by a factor of 7 between similar suites, electricity by a factor of 5, hot water by a factor of 13, cooling by a factor of 47, and heating by a factor of 67. Results show that physical building characteristics explain 43% of the heating variability, 16% of the cooling variability, and 40% of electricity variability, suggesting that the remainders could be a result of occupant behaviour and demographics. It was also discovered that 52% of respondents were not using their energy recovery ventilators [ERV] for the following reasons: acoustic dissatisfaction, difficulty with accessibility of filters, occupant knowledge and preferences, and a lack of engagement with training materials. Results suggest that abandoning mechanical ventilation in favour of passive ventilation could actually lead to greater satisfaction with indoor air quality and to decreased energy consumption. Using content analysis of questionnaire comments, the utility of contextual factors in understanding energy use and satisfaction in the study buildings, as well as their value in producing feedback for designers and managers, was explored. Combining quantitative and qualitative datasets was an effective approach to understanding energy use in this understudied building type.

The importance of understanding occupant behaviour in buildings: exploring the nexus of design, management, behaviour, and energy use in green, high-rise residential buildings

The quest to ‘green’ the built environment has been ongoing since the early 1970s and has intensified as the threat of exceeding 450 ppm of atmospheric carbon dioxide has become more real. As a result of this, many contemporary residential high-rise buildings are designed with hopes of achieving carbon emission reductions, while not sacrificing occupant satisfaction, or property value. Little is known about how the occupants of these buildings contribute to the energy and water consumed therein, nor the effects that these design aspirations have on occupant satisfaction. The present study relies on data collected in four recently built, Leadership in Energy and Environmental Design [LEED] certified, high-rise, residential buildings in Ontario, Canada. Using various sources of data (i.e., from energy and water submeters, questionnaire responses, interviews, and physical data relating to each suite) the extent to which physical, behavioural, and demographic variables explain suite-level energy and water consumption was explored. Energy use intensity differed by a factor of 7 between similar suites, electricity by a factor of 5, hot water by a factor of 13, cooling by a factor of 47, and heating by a factor of 67. Results show that physical building characteristics explain 43% of the heating variability, 16% of the cooling variability, and 40% of electricity variability, suggesting that the remainders could be a result of occupant behaviour and demographics. It was also discovered that 52% of respondents were not using their energy recovery ventilators [ERV] for the following reasons: acoustic dissatisfaction, difficulty with accessibility of filters, occupant knowledge and preferences, and a lack of engagement with training materials. Results suggest that abandoning mechanical ventilation in favour of passive ventilation could actually lead to greater satisfaction with indoor air quality and to decreased energy consumption. Using content analysis of questionnaire comments, the utility of contextual factors in understanding energy use and satisfaction in the study buildings, as well as their value in producing feedback for designers and managers, was explored. Combining quantitative and qualitative datasets was an effective approach to understanding energy use in this understudied building type.

Closing the gap: an assessment of mixed-method data collection techniques in post occupancy evaluation

Demand for energy efficient buildings has supported an increase in predictive performance modeling. However, operation of buildings can often be different than predictive models, creating a collective performance discrepancy referred to as the “performance gap”. Post Occupancy Evaluation (POE) can close this gap by evaluating performance, and contrasting operational data to design intention. This POE demonstrates an identifiable performance gap in a practical case study on one high-performance building. Findings suggest the case building is not meeting anticipated energy consumption with a higher than predicted energy use intensity (EUI). Additional findings indicate a leaky building enclosure, significant thermal bridging, unrealistic simulation assumptions, acoustic disturbances, and occupant thermal comfort satisfaction. This POE demonstrates that mixed-method data collection provides more information than singular analyses when attempting to identify a performance gap. It is demonstrated that qualitative data collection techniques explain quantitative findings in analysis, informing understanding of performance gap causation.