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This paper introduces a database of 34 field-measured building occupant behavior datasets collected from 15 countries and 39 institutions across 10 climatic zones covering various building types in both commercial and residential sectors. This is a comprehensive global database about building occupant behavior. The database includes occupancy patterns (i.e., presence and people count) and occupant behaviors (i.e., interactions with devices, equipment, and technical systems in buildings). Brick schema models were developed to represent sensor and room metadata information. The database is publicly available, and a website was created for the public to access, query, and download specific datasets or the whole database interactively. The database can help to advance the knowledge and understanding of realistic occupancy patterns and human-building interactions with building systems (e.g., light switching, set-point changes on thermostats, fans on/off, etc.) and envelopes (e.g., window opening/closing). With these more realistic inputs of occupants' schedules and their interactions with buildings and systems, building designers, energy modelers, and consultants can improve the accuracy of building energy simulation and building load forecasting.

In many existing high-rise multi-family buildings, a pressurized corridor ventilation system is used to meet outdoor air ventilation requirements. However, this system often has poor performance, leading to under- or over- ventilation in different parts of a building. This study examines three ventilation strategies including: the base case, which is a traditional pressurized corridor ventilation system, a direct-to-suite ducted ventilation system, and a suite-based HRV ventilation system. A building model was constructed in CONTAM using features of a typical post-war multi-family building in Toronto, Canada. All three strategies were simulated using CONTAM under both summer and winter conditions. The resulting outdoor airflow delivery rates to the suites and corridor pressure differentials were compared to assess the effectiveness of each strategy. The results show that the suite-based HRV strategy is able to provide adequate ventilation airflow to individual suites in both summer and winter. In the traditional pressurized corridor system and the direct-to-suite ducting system, the airflows delivered to the suites located at the top of the building are higher than those delivered to the suites located at the bottom of the building. This uneven airflow distribution is more pronounced in winter when stack effect impacts the ventilation system more significantly.

Outdoor environmental noise is a major source of annoyance in urban areas and exposure to it can increase the risk of severe health issues. Consequently, it has been the focus of research for decades. Even though people spend the majority of their time indoors, most studies use outdoor noise levels and do not include indoor noise measurements to estimate real exposure levels. This study conducted simultaneous indoor and outdoor noise measurements for 24 h in four multi-unit residential buildings to identify the levels and sources of outdoor noise heard indoors and quantify the effects of outdoor noise on indoor levels. The measurements were conducted in unoccupied suites that are most exposed to traffic and other outdoor noise sources. Surveys were administered following building occupancy to collect information regarding perceived acoustic comfort levels due to outdoor noise. The indoor LAeq,24h in three of the study buildings were above 40 dB(A) and exceeded WHO's noise level limits. Regression analysis showed that outdoor noise only explains 14%–58% of the variability in indoor noise levels. This is mainly because of heating, ventilation, and air conditioning (HVAC) system noise which resulted in consistently high indoor noise levels despite variations in outdoor noise. Analysis of the survey showed a poor correlation between reported annoyance and measured noise levels. But annoyance strongly depended on other factors such as suite location and noise sensitivity. The findings show that outdoor noise measurements alone may not be good predictors of exposure levels and the effects of outdoor noise on occupants. [ABSTRACT FROM AUTHOR]

Ventilation system performance in high‐rise multi‐unit residential buildings (MURBs) has a significant impact on resident wellbeing. While the importance of ventilation is well established, it is commonly overlooked since underperformance often goes undetected. This article presents a review and synthesis of ventilation system performance in high‐rise MURBs located in cold climates as it relates to the three pillars of sustainability: economic (capital and operational cost), social (airflow control, indoor environmental quality, and occupant behavior and interactions), and ecological (energy and carbon). A meta‐analysis revealed previous ventilation system designs generally prioritized economic sustainability, specifically, capital cost. However, priorities have recently shifted toward social and ecological sustainability. While this shift is positive, there is insufficient empirical evidence showing which ventilation system most effectively supports it. The decentralized heat/energy recovery ventilator (HRV/ERV) system shows the potential to improve upon the social and ecological sustainability of previous designs, such as the centralized pressurized corridor system, but the interconnected nature of performance metrics can cause improvements to one to negatively impact others. Therefore, further research is required to enhance ventilation system performance in cold climate, high‐rise MURBs, and facilitate decision‐making while designing and retrofitting these systems. [ABSTRACT FROM AUTHOR]

Wellbeing in buildings is often approached by practitioners and researchers as the aggregate result of individual interactions between building occupants and building features. This sum-of-the-parts approach, however, ignores the ways in which broader social (i.e. sense of ownership and belonging) and symbolic (i.e. what it means to be 'well' in a specific culture at a particular place and time) components of wellbeing influence occupant experience of the built environment. A social practice perspective on wellbeing in buildings is proposed that accounts for these elements. Beginning with discussions of how wellbeing has been assessed and the foundations of social practice theory, it is suggested that occupant wellbeing is emergent not just from individual interactions with building features but also from broader social and symbolic elements. [ABSTRACT FROM AUTHOR]

Trends of urbanization, densification, and telework all point to increasing exposure to ambient noise for workers. With the lockdown policies implemented in response to COVID-19, a research opportunity to study perceived noise exposure for teleworking arose. This paper presents the results of a survey on noise issues in multi-unit residential buildings (MURBs) and the consequent effects on occupants' well-being and productivity during the lockdown. Responses were collected from 471 MURB occupants across Canada. The results show that, despite the decrease in environmental noise, many are annoyed by outdoor noise, particularly from traffic and construction activities, and indicated that it affects their ability to work. Effects on ability to work from home were more frequently reported for indoor noise sources particularly airborne and impact noises coming from neighboring suites. Our findings, however, show that noise coming from occupants in the same suite (i.e. roommates and family) present the biggest issue. The findings indicate that existing noise conditions in MURBs might not be suitable for a permanent large-scale implementation of teleworking. [ABSTRACT FROM AUTHOR]

While occupancy-based control and other demand management control strategies have demonstrated potential, little is known about how these changes in heating, ventilation, and air-conditioning (HVAC) control impacts occupants' perception of the thermal conditions in their home. In this paper, occupants' thermal comfort perceptions and use of thermostat overrides under three different control strategies (programmable thermostat operation, occupancy-reactive control, and pre-cooling/pre-heating for load shifting) are analyzed. Thermal comfort data were collected through six occupant surveys administered to 54 participants in the summer and winter months in two high-rise condominium buildings in Toronto, Canada. Minor changes to reported thermal sensation scores were observed in both the occupancy-based and load shifting control scenarios, however, overall reported thermal sensation scores remained neutral. Occupants' use of overrides did not change significantly during occupancy-based control periods, however, during load shifting control, occupants frequently overrode strategy temperature setpoints – which indicates that many participants likely experienced thermal discomfort beyond their tolerance level. Occupants' use of strategy overrides during load shifting control strategy operation in the cooling season significantly reduced strategy efficacy. Reducing the maximum temperature setback during load shifting control to 3 °C during the cooling season was recommended to reduce occupant override and improve realized peak-period load reductions. [ABSTRACT FROM AUTHOR]

Connected thermostat data provide new opportunities to access heating, ventilation and air conditioning (HVAC) operation and indoor condition data in high-rise residential buildings. However, how well these thermostat data reflect actual conditions and operation is unclear and best-practices to leverage these data for energy use modelling are needed. Connected thermostat data from 54 suites in two high-rise residential buildings are used to investigate the accuracy of thermostatreported suite condition and HVAC runtime data and the relationship between suite-HVAC runtime and thermal energy demand. Next, data-driven approaches for forecasting suite HVAC runtime are explored. Two key challenges when using these data for energy modelling were identified. First, while a linear relationship between HVAC runtime and thermal energy demand was observed, there was significant variation in this relationship between suites. Second, the simple, data-driven regression methods tested were largely ineffective in accurately predicting suite-level HVAC runtime for hourly intervals (average error: 30%). [ABSTRACT FROM AUTHOR]

Housing aims to provide society with comfortable, healthy living spaces and its built form ultimately shapes the built environment. Consequently, its design, operation, and interactions with infrastructure systems are a powerful determinant of environmental, economic, and social impacts. This paper highlights the importance of assessing housing built forms by answering ten critical research questions. Throughout this paper, we refer to housing built form as the physical properties (e.g., residential density, floor area ratio) of residential buildings and their interactions with adjoining properties (e.g., setback, shading). In Q1 and Q2, we summarize the planning policies that led to current built forms associated with housing and their sustainability impacts, with specific focus on North America and some countries in Australasia. Q3 describes the adverse sustainability impacts of detached single-family houses, while Q4 examines future economic, demographic, and climatic changes that will warrant rethinking housing built form. Q5 summarizes the methods to assess the environmental, economic, and social impacts of housing built form. In Q6 and Q7, we discuss various system boundaries and functional units that are considered for housing life cycle assessment. Q8 and Q9 describe the temporal uncertainty and contextual circumstances underlying housing projects that need to be considered in life cycle assessments. Lastly, Q10 provides a summary of future policy directions to promote housing with lower environmental impact. This paper supports decision-making around meeting housing targets without compromising the environment. • Ten relevant questions on housing built form considering planning policies and impact assessment tools are posed. • Housing built forms are determinant of environmental, economic, and social impacts. • Past, present, and future housing built forms are reviewed. • Life cycle assessment is a useful tool for analyzing the environmental impact housing built form. • Planning policies to support and increase competitiveness of low impact housing built form are provided. [ABSTRACT FROM AUTHOR]

Interior building airtightness affects energy consumption and indoor air quality (IAQ) in multi-unit residential buildings (MURBs). Coupled CONTAM-EnergyPlus simulations were used to assess energy and IAQ performance for 4-storey and 20-storey MURBs for a Toronto, Canada climate. Different interior and exterior partition and door airtightness values and mechanical ventilation systems were assessed (including in-suite heat recovery ventilators (HRVs), pressurized corridor systems (PC) and direct-to-suite ducted systems (DTS). Three contaminants were emitted in all suite zones (CO 2 , NO 2 and PM 2.5). IAQ was assessed using annual average zone contaminant concentrations and the annual average fraction of suite concentration that originated from other zones, to quantify inter-zonal contaminant transport. Annual average suite fractional CO 2 concentrations ranged from 3 to 35% for all airtightness and mechanical ventilation configurations; NO 2 and PM 2.5 ranges were 2–23% and 0–12%, respectively. HRV cases had the lowest space conditioning energy use intensities (EUI) and annual average suite fractional concentrations, compared to the respective PC and DTS cases. Interior partition and elevator/stairwell door airtightness had minimal effects in the 4-storey cases, but significantly reduced space conditioning EUI and fractional suite concentrations in the 20-storey cases, especially for cases with "loose" building envelope airtightness. Tightening interior/exterior partitions reduced inter-zonal contaminant transport, but increased source zone concentrations by reducing dilution. The results generally corroborate previous studies and highlight the importance of tightening both suite and shaft partitions, especially in tall buildings, and coupling compartmentalization with adequate mechanical ventilation. • Compartmentalization reduces inter-zonal contaminant transport. • Zone contaminant concentrations increase with increased compartmentalization. • Tightening shaft doors reduces indirect contaminant transport in high-rise MURBs. • Low corridor supply air flow rates can facilitate indirect contaminant transport. [ABSTRACT FROM AUTHOR]

The En-ROADS Climate Workshop, the GMB workshops, and the prioritisation workshops were exclusively online with everybody participating via their own computer or tablet. The tower refurbishment workshops were of hybrid nature: the first workshop brought the facilitator in online, and the second workshop incorporated some online participants into an otherwise in-person setting. After an introduction of the purpose of the meeting, a brief introduction about CLDs at the first workshop or a recap at subsequent workshops, the main part of the workshops was devoted to GMB activities (see I Table i 4). [Extracted from the article]

Inter‐zonal airflows within multi‐unit residential buildings (MURBs) have profound impacts on an array of building performance metrics, including energy, indoor air quality (IAQ), fire and acoustical separations, and distribution of ventilation air. Although there are wide‐ranging implications, most building codes/standards have yet to incorporate airtightness requirements for interior partitions in large, multi‐zone structures, and instead focus primarily on exterior envelope airtightness. Despite the multi‐disciplinary nature of the topic, previous reviews have been limited to one domain (eg, energy performance, IAQ, specific test methods). This paper presents a comprehensive summary of the literature on inter‐zonal airflow in MURBs including the magnitude and interaction of driving forces; its relevance to/effect on building performance; current code requirements; testing methods; and previous measurements. While considerable efforts have been made in recent years to quantify and control inter‐zonal airflows, most measurement techniques are still labor‐intensive and disruptive, and there is no framework for how to implement performance‐based requirements into building codes and standards. Further research efforts should be focused on refining testing methods and preparing the construction industry for code changes. [ABSTRACT FROM AUTHOR]

There is limited research on noise exposure in multi-unit residential buildings (MURBs) despite the proven effects of noise on people’s physical and psychological health. This motivates the current study which aims to identify important noise sources in MURBs and investigate factors that impact acoustic comfort as well as determine the various impacts of noise on occupants. An online survey was administered to collect subjective assessments of noise exposure and the effects of noise from 213 occupants. Results of a Spearman’s correlation analyses show that, among the different outdoor noise sources, traffic noise annoyance has the strongest significant correlation with overall outdoor noise annoyance (correlation coefficient = 0.64, p = 0.000). Similarly, annoyance with airborne noise through floors/ceiling has the highest correlation with overall indoor noise annoyance (correlation coefficient = 0.47, p = 0.000). The findings show that building age, floor level, proximity to ongoing construction, existence of balcony, number of bedrooms, proximity to elevators and garbage chute are important buildingrelated factors that impact noise annoyance. The results also show that personal and demographic factors, such as occupants’ age, length of residency, ownership status, relationship with neighbors, and willingness to pay for better acoustic conditions, significantly affect subjective responses. Even though both indoor and outdoor noises cause annoyance, outdoor noises, especially noise from traffic, construction and neighborhood activities, cause more annoyance and sleep disturbance compared to indoor noise sources. [ABSTRACT FROM AUTHOR]

A proposed retrofit strategy for high-rise residential buildings involving compartmentalization of apartment units and decentralised in-suite ventilation with heat recovery was studied in order to determine the impact on overall space heating energy for the building and the associated greenhouse gas (GHG) emissions. Field data from a case study building in Vancouver, Canada is used to create a calibrated energy model of the building using EnergyPlus simulation software, which was then used to simulate the proposed retrofit and estimate its impact on energy use. The simulation shows annual space heating energy decreasing by 49% with the associated GHG emissions decreasing by 70%. These results are compared to the measured impact of an enclosure retrofit which had been previously implemented on the building. The enclosure retrofit had a 55% decrease in measured impact on reducing the overall heat loss – slightly greater than that of the proposed retrofit – however the associated GHG emissions only decreased by 25% since only electric heating energy was impacted in this case, the source of which is a hydro-electricity dominated grid. With both retrofits (enclosure plus compartmentalization and in-suite ventilation with heat recovery) done together, a 78% reduction in total space heating energy and an 83% reduction in associated GHG emissions are realised. Another major benefit of the proposed retrofit would be improved indoor air quality for the building's occupants due to a significant improvement in mechanical ventilation distribution effectiveness. Because building enclosure air-tightness improvements can negatively impact air distribution in buildings with pressurized corridor ventilation systems, the proposed retrofit should be applied in combination with, or before, an enclosure retrofit. Thermal resilience should also improve, with longer passive surviveability durations from a reduction in uncontrolled air leakage induced by stack effect. [ABSTRACT FROM AUTHOR]

In North America, the majority of homes use forced‐air systems for heating and cooling. The proportion of time these systems operate, or runtime, has a significant impact on many building performance parameters. The recent adoption of smart thermostats in many North American homes presents a potential data source for runtime. Smart thermostat data collected from over 7000 homes were compared with nine other investigations and a runtime estimation method based on exterior temperature. The smart thermostat runtimes have a median of 18% across all homes, but show considerable variation between homes, even at constant exterior temperature conditions suggesting that factors besides climate (eg, system sizing, user operation) have a significant impact on runtime. Results from other investigations suggest that smart thermostat runtimes are consistent with other measurement approaches. The practical implications of runtime include the impact on central filtration performance. At low to average runtimes, the filter efficiency matters much less for effectiveness because the system does not run enough for a sufficient air volume to pass through the filter and have a substantial impact on particle concentrations. This work illustrates the importance of measuring runtime for a particular home, and the value of data obtained from smart thermostats. [ABSTRACT FROM AUTHOR]

Building infiltration rates are one of the most uncertain parameters among multi-unit residential building (MURB) energy model inputs and have the potential to greatly impact building energy consumption. Infiltration rates exhibit high spatial and temporal variability and are highly building-specific making them difficult to estimate from published data. Reduction of parameter uncertainty using on-site measurements has traditionally been prohibitive, both from a cost and a logistical standpoint. Window component infiltration rate testing was conducted at two MURBs to develop component-weighted infiltration rates, which were input into whole-building energy models and compared with models that used a single building-level infiltration rate. The component-weighted infiltration rate allowed for the incorporation of building-specific measurements, which helped to reduce parameter uncertainty during model calibration. The component-weighted approach also helped to account for the variation in zone infiltration rates based on type and quantity of leakage paths. The discretization of the infiltration rate by building component can help during the modeling of energy retrofits that specifically target building infiltration, by setting bounds on the maximum possible improvement. Implementation of a component-weighted approach will help to improve model calibration and energy retrofit analysis in whole-building energy models, allowing owners and operators to make better-informed decisions regarding energy retrofits. [ABSTRACT FROM AUTHOR]

In the context of suite compartmentalization in multi-unit residential buildings, knowing the airtightness of individual pressure boundaries (e.g. floor, corridor wall, suite wall, etc.) is imperative for the diagnosis and remediation of issues such as regulating ventilation air delivery and managing pollutant transfer. However, conventional quantification methods, such as the pressure neutralization method, are cumbersome to complete. The feasibility of an acoustic testing approach, which leverages the relationship between increased air leakage rate and decreased airborne sound transmission loss was examined. Limited studies have explored this relationship in building enclosure elements, and no attempts were made to assess the correlation in interior partitions. In-situ measurements were conducted across twelve suite partition walls from three multi-unit residential buildings to obtain experimental correlations between the two parameters. The area-normalized air leakage rate at 50 Pa (q 50) varied among specimens of the same composition, demonstrating the importance of air-sealing details for the overall partition airtightness. The variation in q 50 was best reflected by the area-normalized sound transmission loss at 630 Hz; a non-linear model and the inclusion of air pressure differential information also improved the models' accuracy. While the root-mean-square error of 0.56 L/s/m2 in q 50 prediction suggests this acoustic approach needs further refinement to verify compliance with increasingly stringent compartmentalization targets, the current study demonstrates the application and potential benefits of the acoustic approach in a real-world context. Further data could improve the model so that it could be suitable for screening partitions with similar construction and in pre- and post-retrofit comparisons. • Acoustic-airtightness correlation of interior walls was explored using in-situ data. • An acoustic method is feasible for screening suite compartmentalization in MURBs. • Theoretical sound attenuation cannot replace field data in developing airtightness correlation. • Air sealing increases sound insulation of interior partition walls. • Airtightness is best reflected by airborne sounds transmission loss at around 630 Hz. [ABSTRACT FROM AUTHOR]

Residential buildings contributed 14% of Canada's greenhouse gas emissions in 2014, making this sector pivotal to climate change mitigation. In 2016, the provincial government of Ontario, Canada mandated a net-zero carbon standard for new “small buildings” by 2030, meaning the low-rise residential sector must undergo major changes to meet this target. Through an energy modelling analysis of a typical single-family home in Ontario, this study demonstrates the potential carbon emissions savings of different reduction strategies, including changes to the building envelope and mechanical system. The most effective strategies include increasing building airtightness, installing additional exterior insulation, and switching to an air source heat pump for heating and cooling. These strategies were then analysed based on the incremental cost above a house built to the building code baseline. In terms of cost per kilogram of carbon mitigated, the most efficient strategies are further insulating the basement, adding additional exterior insulation, and increasing the efficiency of the heat recovery ventilator. Finally, a policy discussion demonstrates that carbon reductions implemented at the design stage must be verified and monitored post-occupancy using policy tools such as energy reporting and small-scale performance studies. [ABSTRACT FROM AUTHOR]

Improving inter-zonal airtightness in multi-unit residential buildings (MURBs) has wide-ranging benefits including reduced odour/pollutant transfer, reduced sound transmission, and improved energy efficiency. The current metric used to assess inter-zonal airtightness in MURBs is the unguarded air leakage rate, which measures the air leakage through all interior and exterior suite boundaries. While this metric provides a general indication of overall suite airtightness, it provides no information on the location or distribution of leakage pathways across the individual suite partitions. Depending on the construction type(s) of suite partitions there may be variability in air leakage rates at the partition level, which is masked by the whole-suite metric. This makes it difficult to identify potential areas for improvement in design and construction practices. Guarded blower door testing was completed in 14 suites in six newly constructed/renovated MURBs, in Southern Ontario, Canada. Whole-suite air leakage rates for the sample were generally low, consistent with previous studies. Broken down by partition type, floor/ceiling and suite-to-suite walls exhibited similar levels of airtightness, with sample means of 0.36L/s/m2 and 0.32L/s/m2, respectively, at 50Pa (0.07cfm 50 /ft2 vs. 0.06cfm 50 /ft2). In contrast, the average suite-to-corridor wall air leakage rate was nearly eight times higher (2.46L/s/m2 (0.49cfm 50 /ft2)). The results highlight the need to develop targeted air sealing strategies to improve suite-to-corridor wall air leakage rates. Recommendations for improving inter-zonal air sealing practices in new construction are discussed. The measurements reported in this work will also help to improve building airflow simulations, which rely on partition-level air leakage metrics for model inputs. • There is variability in air leakage rates between partition and construction types. • Concrete partitions are typically more airtight than steel stud partitions. • Suite-to-corridor walls have higher air leakage rates than suite-to-suite walls. • Improved interior air barrier detailing/quality assurance practices are recommended. • Partition air leakage rates can be used to improve airflow simulation inputs. [ABSTRACT FROM AUTHOR]

With the expectation of increasing frequency and magnitude of extreme events caused by climate change, one of the most critical yet overlooked aspects of building design in the industry is thermal resilience. An effective way to assess and quantify a building's resilience in the design phase is through modeling and simulation; however, there has been limited effort invested in operationalizing this practice. The purpose of this paper is to provide a critical review of past modeling and simulation research focused on quantifying the thermal resilience of buildings, and to discuss future areas of research that are needed to enhance and standardize practice, as well as building codes and standards. The paper begins by defining a framework for building performance simulation-aided resilience quantification. Next, we review the current state of the art research on a variety of topics such as heat stress and resilience metrics, model assumptions and setup, simulation tool capabilities, weather file type selection, and methods to visualize and communicate resilience. Finally, a discussion on the fundamental research and future tool development needs to accelerate transition from research into practice is presented. • There is urgent need to consider thermal resilience in building design process. • Different methodologies and metrics for analysis are found in existing literature. • Simulation practices to evaluate building thermal resilience are thoroughly analyzed. • Standard practices are needed to better reflect occupant tolerances and reaction. • Practical tools can be developed to facilitate model conversion and results analysis. [ABSTRACT FROM AUTHOR]

To improve the energy performance of Toronto's post-war multi-unit residential buildings (MURBs), these buildings must be energy retrofitted. Here, a novel energy retrofit strategy employing air-source heat pumps (ASHPs) operating in enclosed balcony spaces is assessed. The enclosed balcony provides a thermal buffer zone (TBZ) which can improve the coefficient of performance of the ASHP compared to typical exterior operation by accessing captured solar gains. The estimated energy savings associated with implementing this retrofit strategy was determined using a hybrid modeling approach. A calibrated energy model of a 1968 MURB represented the base case energy consumption. Then, a supplementary algorithm, developed based on laboratory testing, was used to determine the quantity of energy that could be extracted from the TBZ and delivered to the north- and south-facing suites as well as to hot water storage. The modeling exercise yielded estimated whole-building energy and greenhouse gas emissions savings of 39% and 45%, respectively. Due to utility prices at the time of writing, the energy cost savings do not present a compelling financial case. However, the qualitative benefits of this retrofit strategy include suite-based control for occupants and the ability to sub-meter space heating energy use at the suite-level. [ABSTRACT FROM AUTHOR]

Energy modeling is a useful tool for evaluating the performance of contemplated building energy retrofit measures. Traditionally, energy models are developed using data collected from building floor plans and site visits and are then calibrated using utility bills. In the work presented here, an energy model for an existing multi-unit residential building (MURB) was developed using this traditional approach. Next, a refined approach was taken. Using data gathered from a suite-based monitoring program, input data uncertainties in the energy model were addressed. Data from one year of monitoring were assembled to characterize the actual building performance and to calibrate this refined energy model. In order to identify which parameters could be used to improve the model accuracy, the output of this refined model was compared to the output from the traditional modeling approach. It was found that the interior temperature measurements and the sub-metered suite electricity use were the most beneficial in refining the energy model. However, other data collected including window operation and differential air pressures were useful for determining how the building was operating. The use of a local weather file generated from a roof-top weather station has also been discussed. [ABSTRACT FROM AUTHOR]

Abstract: The residential sector accounts for approximately one fifth of Canada's secondary energy use and greenhouse gas emissions. Thus, addressing the energy efficiency of residential buildings has a significant role to play in reducing the nation's overall greenhouse gas emissions. The Ontario Building Code has recently been updated to reflect a more stringent energy performance standard. A home built to the prescribed minimum requirements will perform at a relatively high standard with respect to energy use when compared to homes built less than a decade ago. This paper explores three energy efficiency upgrade options which improve upon the energy efficiency of the 2012 Ontario Building Code. The “controlled ventilation” upgrade involved tightening up the building envelope and adding heat recovery to waste air streams, and two additional upgrade options were developed to meet the high performance targets of the R-2000 standard. While the upgrades explored did not show financial benefit for individual homeowners at current utility rates, if the benefits to society are considered, the upgrades are an economically efficient method of reducing greenhouse gas emissions owed to energy consumption. In addition to highlighting the need for a broader approach to the cost-benefit analyses associated with these types of upgrades, this finding also warrants a discussion about how to transform the current housing market so that energy efficient homes are more appropriately valued. [Copyright &y& Elsevier]

Highlights: [•] Laboratory testing of an air-source heat pump in a thermal buffer zone was completed. [•] An energy model was developed and calibrated to the laboratory data. [•] Improved coefficient of performance was found with increasing heat gains to the thermal buffer zone. [Copyright &y& Elsevier]

Solar chimneys are passive ventilation systems that leverage solar energy to supplement or replace mechanical ventilation. Here we present a novel flow network analysis method for solar chimneys in high-rise buildings and use this method to develop insights into the design of these systems in high-rise multi-unit residential buildings (MURBs). The proposed method differs from others as it relies on a flow network that is less computationally intensive than computational fluid dynamics methods, but it can consider more complex system layouts than existing flow network methods, allowing for characterization of these systems in high-rise buildings. The method was validated by comparing results to other studies in the literature, showing that it can match the flow rates reported for single-floor systems within a 5% error, and qualitatively match the trends from studies of multi-floor systems. We use a case study to demonstrate how the model can be used to analyze the performance of a solar chimney in a high-rise MURB. The results indicate that the air flow rate to each floor induced by the solar chimney is proportional to collector width and solar flux, and inversely proportional to the inlet temperature and the number of floors. The method detailed in this study can be used by practitioners and researchers to develop simulation programs, and the case study results can be used to improve solar chimney design in high-rise MURBs. • A flow network model for solar chimney analysis in high rise buildings is presented. • The model is used to parametrically analyze a case study building. • Increasing building height decreases the flow delivered to each floor. • Increasing collector width increases the flow delivered to each floor. • Decreasing supply air temperature increases the flow delivered to each floor. [ABSTRACT FROM AUTHOR]

Highlights: [•] Correlations between building characteristics and energy use were investigated. [•] A wide range of energy intensities were found and no typological trends established. [•] Fenestration ratio and boiler efficiency were the most influential variables. [•] Required reporting of building energy-use data was recommended. [Copyright &y& Elsevier]

Although building energy simulation is an essential tool for designers, numerous studies have proven the existence of a performance gap between the estimated and measured energy use. In response, researchers are exploring ways to collect authentic behavioural data to improve existing inaccurate data-driven occupancy behaviour models. An important occupant behaviour currently being studied is window operation behaviour as it results in large consequences on heating/cooling loads and ventilation rates of a building. Ex-situ camera-based window operation monitoring has been proposed as a solution. This study used image processing technologies that automatically identified windows on a façade and determined their individual state (i.e. open, partially open, or closed). The algorithm developed through this study yielded an 89% accuracy rate over all the windows tested. This algorithm was developed to specifically target punched façades with awning windows. Factors that affected the accuracy of ex-situ camera-based window operation monitoring included environmental conditions such as lighting, obstructions, and reflections. Furthermore, there were challenges in determining threshold values used to isolate important image data that defined the window state and location and identifying the significant peaks for window angle image data. The next steps for this research should determine appropriate threshold values that can be used universally through additional testing and to explore new image processing techniques for other window types. • Underdeveloped data-driven occupancy behaviour models contribute to inaccurate simulated energy use. • Ex-situ camera-based system can monitor window behaviour and reduce Hawthorne Effect. • Employed image processing strategies for awning windows on punched facades. • Algorithm produced 90% accurate readings during tests. • Limitations included threshold values and environmental factors during snapshot. [ABSTRACT FROM AUTHOR]

As the proportion of the population who resides in urban centers grows, the number of dwellings in high-rise residential buildings is also increasing. In Canada, heating, ventilation, and air conditioning (HVAC) typically accounts for over half of all energy use in this building type and, as such, consideration of these loads is key to effective energy demand-side management. Smart thermostats present a new opportunity conserve energy and shift electricity load to off-peak periods in these buildings through modifications to HVAC control strategies. In this study, three thermostat control strategies were tested in 49 suites across two contemporary high-rise residential buildings: 1) baseline operation (thermostat operating as a standard programmable thermostat); 2) occupancy-based control (thermostat operating using an occupancy-reactive control strategy); 3) load shifting control (thermostat operating using a pre-conditioning strategy). HVAC runtime data was collected from smart thermostats installed in the suites and was used to develop data-driven regression models to estimate baseline suite HVAC runtime based on weather conditions and suite characteristics. Thermostat-measured HVAC runtime data for periods in which occupancy-based or load shifting control strategies were in use in the suite was then compared with estimated baseline runtime for similar outdoor conditions. Occupancy-based control was found to reduce HVAC system runtime during the cooling seasonby 5.9% ± 46% on average. On aggregate, the load shifting control strategy was not effective at reducing peak period HVAC load during the cooling season. The strategy was able to reduce peak period loads in a subset of suites substantially, which may be leveraged to reduce electricity demand during capacity-constrained periods of grid operation, however, based on marginal emissions factors for Ontario's electricity grid, even in these suites, the strategy was not effective in reducing GHG emissions overall. [ABSTRACT FROM AUTHOR]

In Canada and the United States, pressurized corridor ventilation systems are common in older high-rise multi-unit residential buildings (MURBs). There is growing evidence that these systems exhibit poor performance, necessitating the evaluation of alternatives. This study used a CONTAM air flow model to compare six ventilation systems to the pressurized corridor, including various decentralized and direct-to-suite ducted configurations. The model was generated using field data from a representative 24-storey post-World War II MURB in Toronto, Canada, along with field data from the literature. Simulations were run for each system under cold (−16.1 °C, 3 °F) and warm (29.0 °C, 84.2 °F) outdoor conditions and the results were analyzed for the 2nd and 23rd levels. The novel contributions from this work are insights into air flow within the target building typology and the design recommendations that these insights permit. Key findings include: 1) Reliance on door undercuts to facilitate air flow from corridors to suites results in increased in/exfiltration across the exterior wall by up to 230% under cold conditions; 2) Automated air flow control at ducted supply terminals does not significantly improve the performance of any tested system; and 3) Inter-suite air flow is significant in all of the tested systems, with 20%–31% of the air in the 23rd level suite being attributed to either direct (5%–13%) or indirect (15%–18%) inter-suite air flow during the cold condition. We recommend reducing indirect inter-suite flow, where possible, and avoiding door undercuts and automated ducted supply terminal flow control. • An air flow model was generated in CONTAM of a 24-storey post-war high-rise MURB. • Field and literature data were used to generate and validate the model. • Pressurized corridors and six alternative ventilation strategies were analyzed. • Ventilation, total, and inter-suite air flow rates were compared. • Design recommendations were generated based upon model results. [ABSTRACT FROM AUTHOR]

Smart home technologies are becoming prevalent in residential buildings. Despite interface and control improvements offered by smart thermostats, previous work has found energy savings from this technology to be variable. Further, little is known about how smart thermostat operation differs from conventional programmable thermostat operation, which has been studied extensively. In this paper, data from 54 smart thermostats installed in two high-rise residential buildings are used to characterize smart thermostat programming and occupant interaction behaviours. Survey data are also used to examine how environmental attitudes and technical abilities influence thermostat usage behaviours. Smart thermostat programming rates were higher than those previously found for conventional programmable thermostats, likely due to improved thermostat interfaces. Further, programmed schedule accuracy was high (88% occupancy during scheduled unoccupied periods). Participants programmed substantial setforwards (cooling season average of 2.8 °C) and setbacks (heating season average of 3.8 °C) to be used when their home is unoccupied. Override behaviours were generally not problematic: most overrides had short durations or were frequently adjusted by users. Strong environmental attitudes and technical skills also appeared to result in more energy-conscious thermostat use behaviours, however, due to the population demographics, specific relationships between energy conservation attitudes and thermostat use behaviours were unclear. An analysis of thermostat schedules and setpoints considering measured occupancy data indicated that participant-programmed schedules achieved significant HVAC load reductions when compared to a scenario in which no schedule was programmed. Further, the use of occupancy-based controls, whether alone or in combination with a schedule, was shown to improve energy savings. [ABSTRACT FROM AUTHOR]

Control of inter-zonal air flow in multi-unit residential buildings (MURBs) is currently regulated by ASHRAE 62.2: Ventilation and Acceptable Indoor Air Quality in Residential Buildings , which specifies a maximum whole-suite air leakage rate, normalized by surface area. Despite the fact that the compartmentalization requirement has been in effect since 2013, few studies have explicitly examined the feasibility of the requirement in concrete MURBs. This paper presents results from recent inter-zonal air leakage testing completed in 12 newly constructed MURBs located in southern Ontario, Canada (N = 175). Normalized air leakage under an induced pressure difference of 50Pa (q 50) ranged between 0.16 and 2.51 L/s/m2 (0.03 and 0.49cfm/ft2) of total suite surface area with a mean equal to 0.49 L/s/m2 (0.10cfm/ft2), well below ASHRAE 62.2's limit of 1.52 L/s/m2 (0.30 cfm/ft2). However, guarded blower door testing in concrete MURBs revealed large disparities between the various suite boundary types, suggesting that the whole-suite air leakage rate may not provide sufficient information about partition-based air tightness to identify potential performance issues. While guarded blower door testing provides more useful air tightness data, it is very labour-intensive and time-consuming. Completing the test prior to general occupancy improved testing efficiency slightly; however, new logistical concerns arose when testing on an active construction site. Lessons learned and recommendations for future testing efforts are discussed. • Suite-level air leakage rates were compared to compartmentalization standards. • ASHRAE 62.2 compartmentalization standards are easily achievable for concrete MURBs. • There is high variability in air leakage rates between partition types. • This variability may lead to in-service performance gaps. • Refined test methods are required in order to identify inter-partition variability. [ABSTRACT FROM AUTHOR]

Buildings' expected (projected, simulated) energy use frequently does not match actual observations. This is commonly referred to as the energy performance gap. As such, many factors can contribute to the disagreement between expectations and observations. These include, for instance, uncertainty about buildings' geometry, construction, systems, and weather conditions. However, the role of occupants in the energy performance gap has recently attracted much attention. It has even been suggested that occupants are the main cause of the energy performance gap. This, in turn, has led to suggestions that better models of occupant behavior can reduce the energy performance gap. The present effort aims at the review and evaluation of the evidence for such claims. To this end, a systematic literature search was conducted and relevant publications were identified and reviewed in detail. The review entailed the categorization of the studies according to the scope and strength of the evidence for occupants' role in the energy performance gap. Moreover, deployed calculation and monitoring methods, normalization procedures, and reported causes and magnitudes of the energy performance gap were documented and evaluated. The results suggest that the role of occupants as significant or exclusive contributors to the energy performance gap is not sufficiently substantiated by evidence. [ABSTRACT FROM AUTHOR]

Smart home technologies have long been envisioned as a mainstay in future residential buildings; however, residential smart home technologies have fallen short of expectations. Generally referred to by the literature as occupant-centric controls (OCC), a subset of these technologies focus on sensing and/or managing systems based on occupant feedback, preferences, or perceptions. While past reviews have documented OCC applications in commercial and industrial building types, residential applications have been rarely distinguished as their own unique application of OCC. This article critically reviews the state-of-the art research in both simulation and field-experiments – neither of which fully align with existing commercial smart home OCC technologies. Study demographics, location, building systems, implementation objectives, and experimental methods are compared and critiqued to understand where research, through simulation and field-experiments, needs to be focused. Key identified shortcomings include: low diversity of studied building systems, overly simplified simulation scenarios, short durations of field testing, inappropriate choices of occupant types, and non-standardized implementation performance metrics and test cases. Furthermore, innovation is hampered by limited standardization in technology communication protocols, the inability to integrate systems from different manufacturers, missing technology transfer protocols to translate researched implementations into commercial applications, and a lack of vision and planning for future policies and technologies that enable effective and comprehensive smart home implementations. • Simulation and field research on residential occupant-centric controls is reviewed. • Research findings are hard to compare due to non-standardized metrics and test cases. • Test cases are often simplified; short in duration; or use atypical occupants. • Lack of interoperability of technologies from different manufacturers is limiting. • Innovation is hampered by a lack of vision for comprehensive smart home implementations. [ABSTRACT FROM AUTHOR]

Buildings with highly glazed envelopes have gained popularity in recent decades. Though it is well understood that these modern buildings can be less energy efficient, only a few attempts have been made to examine the impact of certain building design decisions, such as window characteristics, on indoor thermal sensation and thermal comfort. While conventional assessment of thermal sensation and comfort primarily considers zone-level environmental conditions (e.g. air temperature and relative humidity), localized effects including direct solar radiation exposure and ankle draft may also exist and can impact indoor thermal sensation especially in highly glazed perimeter zones. In this work, a simulation framework is introduced to incorporate the solar radiation effect and ankle draft effect, which are shown to increase warm and cold thermal sensation levels, respectively. The novel proposed ankle draft model adapts local draft conditions to determine the impact on overall thermal sensation for the first time. This simulation framework is demonstrated using a single-zone model using the climate of Toronto, Canada to illustrate the effect of three primary window design parameters on thermal sensation using a visualization approach: window size, U-factor, and solar heat gain coefficient. All observations are aligned with anecdotal evidence: warm thermal sensation level is positively correlated with window size and solar heat gain coefficient, whereas cold thermal sensation level is positively correlated with window size and window U-factor. This simulation framework can be used to analyze indoor thermal sensation and comfort for perimeter zones in existing buildings or fenestration alternatives during building design phases. • Direct solar radiation and ankle draft thermal sensation effects are quantified. • A framework is designed for quantifying these two additional effects. • A novel ankle draft model for adjusting the overall thermal sensation is proposed. • Warm thermal sensation level is positively correlated with window size and SHGC. • Cold thermal sensation level is positively correlated with window size and U-factor. [ABSTRACT FROM AUTHOR]

Heating, ventilation and air conditioning (HVAC) operation is the largest contributor to residential building energy use and can significantly influence occupant thermal comfort and behaviours. Despite the boom in high-rise residential building construction, little is known about the relationship between occupant comfort and behaviors and HVAC operation in these contemporary buildings. In this study, connected thermostat data and occupant surveys from 55 participants across two contemporary high-rise condominium buildings were used to characterize this relationship to reveal opportunities for improved comfort and energy efficiency. Survey data indicated that occupant thermal discomfort was prevalent across both buildings in the heating and cooling seasons (48% and 53% reporting discomfort in heating and cooling seasons, respectively). The measured data corroborated the survey findings showing that over-conditioning of suites is a chronic issue across seasons. However, investigation into the temperatures of suites located in different parts of the buildings indicated that the overheating was influenced by wind, solar radiation and winter stack effect, but not in the ways suggested by building physics (e.g. air moving in opposite direction of predicted stack effect). This supports our hypothesis that the MAU operational characteristics and incorrect balancing of air duct networks are likely causing over-conditioning but further investigation is ongoing to confirm this. Analysis of suite HVAC unit runtimes also revealed low runtimes in heating season, which may limit the effectiveness of improved (e.g. occupant-based) in-suite HVAC controls, given the minimal space conditioning energy consumption in these particular suites. This study demonstrates the potential for using connected thermostat data as a diagnostic tool to identify opportunities for energy savings in the building. • Thermostat data and surveys are used to examine the relationship between occupant thermal comfort and behaviours in two condominium buildings. • Approximately 50% of occupants are dissatisfied with thermal comfort conditions in the study buildings. • Over-conditioning of central areas appears to be a major cause of the suite-based thermal discomfort. • The resulting occupant behaviours vary significantly from assumed design conditions, including frequently propping open suite-hallway doors. [ABSTRACT FROM AUTHOR]

• Buildings without in-suite temperature control experience excessive overheating. • A retrofit based upon suite grouping and wireless temperature sensors is proposed. • A case study building is analysed in EnergyPlus using measured field data. • An optimized solution reduces overheating by 68% and energy consumption by 14%.% • The proposed strategy is an economically viable retrofit option for post-war MURBs. This study proposes a novel HVAC retrofit for the space heating systems of post-war multi-unit residential buildings (MURBs). Typically, these buildings do not have in-suite temperature control and each suite must be retrofit with a thermostatic valve to provide this control to residents. However, given the potentially high installed cost of these valves, this retrofit strategy can be cost-prohibitive. To alleviate this issue, a retrofit strategy that uses temperature sensors in each suite with a control system that combines the signals from these sensors is proposed. This approach allows for suite control to be grouped, thereby reducing the equipment quantity, and cost of the retrofit. Field data from a case study building in Toronto, Canada, was used to develop and validate an EnergyPlus simulation tool. Results show that with a financially optimal grouping strategy, a 14% reduction in space heating energy consumption, a 68% reduction in overheating, and a payback period 10 years can be achieved. These results compare favourably to the typical strategy of installing one valve per suite, which resulted in a payback period of 15 years. These findings support that using this novel control strategy can be an effective way of economically improving post-war MURB performance. [ABSTRACT FROM AUTHOR]

Traditionally, less focus has been given to comfort evaluations in residential buildings compared to commercial buildings. Despite having an increased level of control relative to offices, occupants can still experience health and comfort issues in their residences due to poor environmental conditions which can result in adaptations that may increase energy consumption in buildings. Consequently, there have been more studies which evaluate factors that affect occupant comfort and health in residential buildings in recent years. As high-rise multi-unit residential buildings (MURBs) become more ubiquitous in cities globally, researchers have also started to look at factors that affect occupants' comfort in MURBs. In this paper, a critical review of studies which investigated occupant comfort in MURBs in relation to environmental and non-environmental variables that could have a potential impact on comfort is presented. Various approaches used in assessing occupant comfort are compared, the factors which are important determinants of occupant comfort in MURBs are presented, and the gaps in the literature are identified. Findings of this review show that, in addition to indoor environmental conditions, occupants' characteristics, building-related characteristics and the outdoor environment can significantly affect occupant comfort in MURBs. The identified gaps include a limited assessment of the impact of non-thermal related environmental conditions on comfort and the impact of non-environmental related conditions, as well as a limited number of studies on health and productivity. Based on these findings, the paper includes recommendations on research design and methodologies for future occupant comfort studies in MURBs. [ABSTRACT FROM AUTHOR]

Globally, there are significant challenges to meeting built environment performance targets. The gaps found between the predicted performance of new or retrofit buildings and their actual performance impede an understanding of how to achieve these targets. This paper points to the importance of reliable and informative building performance assessments. We argue that if we are to make progress in achieving our climate goals, we need to reframe built environment performance with a shift to net positive goals, while recognising the equal importance of human and environmental outcomes. This paper presents a simple conceptual framework for built environment performance assessment and identifies three performance gaps: (i) Prediction Gap (e.g., modelled and measured energy, water consumption); (ii) Expectations Gap (e.g., occupant expectations in pre- and post-occupancy evaluations); and, (iii) Outcomes Gap (e.g., thermal comfort measurements and survey results). We question which of measured or experienced performance is the 'true' performance of the built environment. We further identify a "Prediction Paradox", indicating that it may not be possible to achieve more accurate predictions of building performance at the early design stage. Instead, we propose that Performance Gaps be seen as creative resources, used to improve the resilience of design strategies through continuous monitoring. [ABSTRACT FROM AUTHOR]

[Display omitted] • A novel air tightness test method for high-rise MURBs has been developed. • The new method has relatively low equipment and labour requirements. • Field data were used to create validated CONTAM models to test the method. • Case studies show estimation errors ranging from −7% to 69% using the new method. • The new method is most appropriate for suites with leakier exterior boundaries. This paper presents a novel method for characterizing the exterior envelope air tightness of high-rise multi-unit residential building suites, the "Selective Pressure Neutralization" (Selective PN) method. Through the neutralization of air flow across the corridor-suite pressure boundary, this method can improve accuracy compared to the typically implemented "Whole Suite" method, while halving the time and equipment requirements of on-site testing compared to the Pressure Neutralization method. A CONTAM model was developed using field data from eight case study suites and then used to simulate the effectiveness of the proposed method in fourteen suite configurations. Sensitivity study simulations were also carried out where individual suite pressure boundary air tightness characteristics were varied. The case study results showed average absolute exterior boundary characterization errors of 16% and 51% for the Selective PN and Whole Suite methods, respectively. The sensitivity study results showed that the Selective PN method meets or exceeds the accuracy of the Whole Suite method by up to 78% in buildings with leakier exterior boundaries, like those in buildings with punched windows (as opposed to window wall configurations). Thus, the Selective PN method shows promise as an alternative air tightness testing method. [ABSTRACT FROM AUTHOR]

• Two alternative air tightness test methods are examined for use in high-rise MURBs. • A sequential pressure neutralization test is successfully performed in a MURB suite. • Field test results are used to calibrate a CONTAM air flow model. • The Love and Passmore method exhibited a characterization error of 108%. • The Lstiburek method exhibited a characterization error of 0.2%. Blower door testing is commonly used to characterize exterior façade air leakage in buildings. This characterization is needed to improve the accuracy of energy models and certify building performance. Performing these tests in large buildings requires air flow rates that are sometimes impractical to achieve using available equipment, which necessitates testing in individual zones within those buildings. However, when performing these tests in individual zones, the conventional whole-suite tests are unable to isolate the required envelope flow characteristics and pressure neutralization tests are, in most cases, too logistically difficult to perform, which necessitates an investigation into alternative methods. In this study, two methods developed for use in row housing were adapted to a high-rise multi-unit residential building (MURB) context in which the test suite is surrounded by adjacent suites: The Love and Passmore method, and the Lstiburek method. The efficacy of these adapted techniques was assessed in a single suite located in a high-rise MURB that followed typical North American construction habits. To carry out these assessments, a combination of field data and calibrated CONTAM simulations are used. For the case study building, the Love and Passmore method exhibits exterior boundary characterization errors of 108%, and is inappropriate for this characterization in high-rise MURBs. Alternatively, the Lstiburek method exhibits an exterior boundary characterization error of 0.2%, but additional analysis showed the Lstiburek method exhibits greater sensitivity to measurement noise than the pressure neutralization method. As a result of this increased noise sensitivity, and because of the similar labour and equipment requirements, it is therefore also not recommended as a replacement for the pressure neutralization method. It is important to note that buildings constructed using different details and techniques may exhibit different results, which is a limitation of this study. Details related to these tests, including a discussion of potential shortcomings and strengths, are presented in this paper. [ABSTRACT FROM AUTHOR]