Building Energy Policy Research Articles

Estimating Spatio-Temporal Building Power Consumption Based on Graph Convolution Network Method

Buildings are responsible for around 30% and 42% of the consumed energy at the global and European levels, respectively. Accurate building power consumption estimation is crucial for resource saving. This research investigates the combination of graph convolutional networks (GCNs) and long short-term memory networks (LSTMs) to analyze power building consumption, thereby focusing on predictive modeling. Specifically, by structuring graphs based on Pearson’s correlation and Euclidean distance methods, GCNs are employed to discern intricate spatial dependencies, and LSTM is used for temporal dependencies. The proposed models are applied to data from a multistory, multizone educational building, and they are then compared with baseline machine learning, deep learning, and statistical models. The performance of all models is evaluated using metrics such as the mean absolute error (MAE), mean squared error (MSE), R-squared (R2), and the coefficient of variation of the root mean squared error (CV(RMSE)). Among the proposed computation models, one of the Euclidean-based models consistently achieved the lowest MAE and MSE values, thus indicating superior prediction accuracy. The suggested methods seem promising and highlight the effectiveness of GCNs in improving accuracy and reliability in predicting power consumption. The results could be useful in the planning of building energy policies by engineers, as well as in the evaluation of the energy management of structures.

Preliminary study on building practitioners’ compliance behaviour with 7-star house energy ratings in Australia: perceptions of industry experts

PurposeFrom May 2024, Victoria (Australia) will mandatorily raise the minimum house energy rating standards from 6 to 7 stars. However, the latest data shows that only 5.73% of new Victorian houses were designed beyond 7-star. While previous literature indicates the issue’s link to the compliance behaviour of building practitioners in the design phase, the underlying behavioural determinants are rarely explored. This study thus preliminarily examines building practitioners’ compliance behaviour with 7-star Australian house energy ratings and beyond.Design/methodology/approachUsing a widely-applied method to initially examine an under-explored phenomenon, eight expert interviews were conducted with building practitioners, a state-level industry regulator and a leading national building energy policy researcher. The study triangulated the data with government-led research reports.FindingsThe experts indicate that most building practitioners involved in mainstream volume projects do not go for 7 stars, mainly due to perceived compliance costs and reliance on standardized designs. In contrast, those who work on custom projects are more willing to go beyond 7-star mostly due to the moral norms for a low-carbon environment. The experts further agree that four behavioural determinants (attitudes towards compliance, subjective norms, perceived behavioural control and personal norms) co-shape building practitioners’ compliance behaviour. Interventions targeting these behavioural determinants are recommended for achieving 7 stars and beyond.Originality/valueThis study demonstrates the behavioural determinants that influence building practitioners’ compliance decisions, and offers insight regarding how far they will go to meet 7 stars. It can facilitate the transition to 7 stars by informing policymakers of customized interventions to trigger behaviour change.

Innovating building energy regulations enabled by radiative sky cooling: Enhanced code of practice for overall thermal transfer value (OTTV) of super-cool roofs

Radiative sky cooling, which utilizes outer space as the cooling source for heat dissipation, is attracting global interests for its ability to cool passively without using any energy. Considering the swift advancements in the production of cost-effective radiative sky cooling materials on a large scale, it is of practical significance to incorporate radiative sky cooling technology into buildings to improve energy efficiency, necessitating amendment of the corresponding regulations. With this objective, the present research particularly focuses on the impact of radiative sky cooling-based super-cool roof strategies on the code of practice for Overall Thermal Transfer Value (OTTV), which is a prescriptive building regulation introduced by the Hong Kong government for building design, aimed at providing correction factors for local typical roofs integrated with advanced radiative sky cooling materials. To achieve the purpose, a new model for predicting roof heat transfer based on radiative sky cooling was established. Scaled-down experiments were conducted to fully validate the developed model with sufficient accuracy. The findings indicate that the implementation of super-cool roof strategies through radiative cooling-based techniques can substantially decrease roof heat gains, with reductions ranging from 73.9 % to 90.7 %, yield considerable energy savings, averaging between 3.5 and 45.0 kWh/m2, as well as significant cost savings on cooling expenses, averaging from 5.8 to 74.2 HKD/m2. Moreover, the adoption of such strategies has the potential to reduce carbon emissions by 6.3 to 81.2 kg/m2 during the cooling season. These outcomes vary depending on factors like the coefficient of performance (COP), radiative cooling materials, and specific roof types. Correlations between roof heat gains and OTTVs are established with a high accuracy of fit, achieving a coefficient of determination as high as 0.978. The average correction factors of five cutting-edge radiative cooling materials range from −0.00563 to −0.01655 in response to different typical roof types. Utilizing these correction factors, incorporating radiative sky cooling materials results in the OTTV of super-cool roofs varying from −0.7216 to −0.239 W/m2, which are significantly below the prevailing OTTV limit of 21 W/m2 enforced for Hong Kong’s commercial buildings. The proposed approach in this study can provide a straightforward and practical approach to assess the OTTV of typical building roofs when integrated with cutting-edge radiative sky cooling materials. This research offers significant perspectives into evolution and innovation of building energy policies incorporating radiative sky cooling technology.

Building Energy Governance: Statutes and Guides on Retro-Commissioning in China and the United States

Reducing building energy use, a linchpin of climate change mitigation, is a daunting challenge across the world. Gaining increasing attention, retro-commissioning (RCx) is a systematic process that can improve building energy performance. Using a techno-legal lens to review statutes and guides on RCx, this study reveals that in China, a national standard on building commissioning has taken effect yet RCx statutes are hitherto not found. The United States has RCx statutes enacted over 14 states; scrutinizing the statutes of five cities unveils similarities and differences in their scope of control and compliance requirements. In the absence of a specific RCx statute, the guide of Hong Kong, China provides detailed guidance for energy saving practices. While these findings can serve as reference for other places planning to formulate laws or guidance on RCx, the need to further study the effectiveness of mandating RCx for reducing building energy use is highlighted. A conceptual analysis of cost variation with statutory control, which could help policymakers consider from an economic perspective whether or to what extent statutory RCx requirements should be imposed, is also illustrated. This not only contributes insights to the pursuit of an optimal balance between statutory control and voluntary action for energy reduction but also adds to the debate on building energy policies.

Construction Cost Decomposition of Residential Building Energy Retrofit

Buildings are responsible for significant energy consumption and carbon emissions. Green buildings, which incorporate advanced building technologies, offer a solution to reducing energy use. However, high costs associated with green building development present a barrier to widespread adoption. Retrofit projects, involving remodeling, renovation, and redevelopment of existing buildings, offer a viable solution. While prior studies have examined the cost analysis of green and non-green buildings, there is a lack of evidence comparing new and retrofit projects. This study aims to address this gap by providing empirical evidence for the cost decomposition and benefits of new and retrofit projects. Data on energy use, building technology, and costs from 235 certified green homes in the United States were collected, and cost benefits were evaluated. Results show that retrofit projects cost, on average, $1270.5/m2 ($118.0/ft2), which is 30% less than new projects. Land acquisition and development account for 35% of retrofit costs, six times greater than new projects. Excluding land costs, retrofit projects cost, on average, $733.88/m2 ($68.2/ft2), 49% less than new projects. Retrofit projects use similar building technologies as new projects and produce larger energy savings. The cost-benefit values generated by retrofit projects are 86% greater than new projects when considering land costs and 142% greater without considering land costs. These findings contribute to cost management for complex building projects and energy policy for sustainable development. Retrofitting offers great potential to promote the green building movement and suggests effective subsidy programs as a public policy implication.

Is energy-efficient building sustainable? A case study on individual housing in Canada under BCESC energy updates

Life cycle thinking and holistic sustainability assessment are missing in current building energy codes globally, with primarily focus on operational energy use and greenhouse gas (GHG) emissions. The overall objective and originality of this study is to evaluate the building-level life-cycle environmental and economic impact of building energy code compliance, exploring the trade-offs between energy savings, various environmental impacts and cost effectiveness, taking the British Columbia Energy STEP Code (BCESC) as a case study. An integrated approach of using building information modeling (BIM) with whole building life cycle assessment (LCA) and life cycle costing (LCC) is proposed, and comparisons of life cycle environmental and economic impacts are studied with respect to each energy upgrade level. The findings revealed that while the total energy demand intensity and GHG emissions decreased (by about 50% compared to base scenario) with the code intervention steps, the other environmental impacts may increase due to the embodied materials, production, and upkeep of the upgrades, for example, the ozone depletion potential increased by nearly 800% compared to the baseline. Additionally, the energy-saving measures reduce building operating costs by about C$4,000, which is significantly less than the increased costs in other stages. However, this incremental cost does not always mitigate the effects of specific environmental impact categories. The findings will be of interest to building industry policymakers to develop more holistically sustainable building energy policies, allocating limited funds in a more cost-effective manner to reduce environmental impacts, instead of focusing solely on direct and temporary benefits.

Evaluation and Validation of Microscale Atmospheric Modeling With Offline Weather Research and Forecasting Model to Parallelized Large-Eddy Simulation Model Forcing Conditions

Abstract As the rate of urbanization increases, local vegetation is being replaced with man-made materials, causing increasingly adverse impacts on the surface-atmosphere energy balance. These negative effects can be simulated by modeling the urban landscapes in question; however, the main challenges of modeling urban thermal environments are the scale and resolution at which to perform such tasks. Current modeling of urban thermal environments is typically limited to either mesoscale (1 –2000 km) or microscale (<1 km) phenomena. In the present work, an open-source framework for one-way upstream coupled multiscale urban thermal environment simulations is examined and validated. This coupled simulation can provide valuable insights into the flow behavior and energy transport between mesoscale and microscale interactions. The mesoscale to microscale boundary conditions are coupled together using simulated data from the advanced research weather research and forecasting model (WRF-ARW), a mesoscale numerical weather prediction software, and assimilating it into parallelized large-eddy simulation model (PALM), a computational fluid dynamics style (CFD-style) software designed for microscale atmospheric and oceanic flows. The multiscale urban thermal environment simulations are tested for grid sensitivity to variations in model input and control parameters, and then experimentally validated against distributed sensor measurements at the Georgia Institute of Technology (Georgia Tech) campus in Atlanta, GA. Validated microscale atmospheric models with heterogeneous domains can be used to project the thermal benefits of urban heat mitigation strategies (increase use of high-albedo surfaces, tree and vegetation cover, and smart growth practices) and advise building energy usage modeling and policies.

Assessing thermal resilience of an assisted living facility during heat waves and cold snaps with power outages

Extreme hot and cold weather events are becoming more frequent, intense, and longer due to climate change. When these events occur coincidentally with power outages, the resulting extreme indoor temperatures pose a severe health hazard for occupants. This study conducted a holistic modeling and analysis of an assisted living facility, where senior residents live, to assess its thermal resilience performance under a six-day heat wave in 2015 and a three-day cold snap in 2021 with power outages. Impacts of 13 energy efficiency measures on thermal resilience and backup power capacity of the facility were evaluated. Three thermal resilience metrics: the SET (standard effective temperature) degree-hours, the Heat Index, and the Hours of Safety, were used and calculated from the EnergyPlus simulation models. Major findings are: (1) the facility would suffer from extreme temperatures during the cold and hot events without a power supply, not meeting the passive survivability requirements; (2) most passive envelope measures improve thermal resilience for both hot and cold events, but making the building envelope airtight results in conflicting performance between the hot and cold events; (3) natural ventilation is an effective measure to mitigate summer indoor overheating; and (4) the energy efficiency package can reduce backup power capacity by 19% for the three-day cold snap. It is recommended that building technologies and design strategies be evaluated to consider co-benefits of energy use, thermal resilience, and backup power needs through building energy codes or policies for existing and new buildings, which are transitioning for decarbonization and climate resilience.

Analysis of heating behaviour based on occupancy patterns in residential building with radiant floor heating system

To achieve a carbon-neutrality, a reduction of heating energy consumption in residential building should be achieved. Although, lots of building energy policies were implemented to reduce heating energy consumption, it still accounts the largest share of global building energy consumption. Large number of researches pointed out the poor heating energy management by occupant makes inefficient heating energy consumption. In this research, the occupancy patterns and heating behaviour in Korean residential building are analysed. The occupancy patterns are identified with electricity consumption collected from 229 households. By comparing the heating energy consumption and occupancy patterns, the heating behaviour in residential building is analysed. The results show that about 81.2% of the analysed households applied continuous heating strategy whether occupants stay in the building or not. About 39.5% of the total heating energy consumption in 229 households, is consumed during unoccupied hours. The result of this research shows that the heating control strategy considering occupancy patterns can be greatly reduce the heating energy consumption in residential building.

Analysis of the additional energy-saving potential of residential buildings after mandatory zero-energy buildings to achieve carbon neutrality in South Korea

Led by the European Union (EU), several countries have announced carbon-neutral goals and introduced related legislations. For example, the Korean government has recently announced a roadmap for the introduction of mandatory zero-energy buildings (ZEBs), because the building sector is a major contributor to carbon emissions. To evaluate the feasibility of achieving carbon neutrality through the legislation of mandatory ZEBs, we analyzed the energy-saving potential of residential buildings and determined whether ZEB standards could be strengthened further. The energy consumption of residential apartments was calculated, and the possibility of additional energy savings beyond those dictated by ZEB certification standards was evaluated by assessing the energy performance of individual element technologies. It was observed that, to achieve carbon neutrality, there were limits to regulating individual element technologies alone, and a comprehensive approach was required. In addition, after the introduction of mandatory ZEBs, the degree to which the hot water and plug loads are affected by user behavior increases; therefore, it is also necessary to design a policy to encourage users to exhibit energy-saving behavior. This study can be used as a reference for the design of building energy policies after the introduction of mandatory ZEBs.

Influencing of the Building Energy Policies upon the Efficiency of Energy Consumption: The Case of Courthouse Buildings in South Korea

As Korea has declared to realize a net-zero emission by 2050 in the Paris Agreement, the country has begun to implement national energy efficiency policies through the Green Standard for Energy and Environmental Design (G-SEED) certification and revision of building insulation thickness standard. However, some studies have reported the ineffectiveness of G-SEED certification and insulation thickness standard in reducing the energy consumption in certain buildings. Therefore, this study investigated the effectiveness of G-SEED certification and the revision of buildings’ insulation thickness standard, and evaluated the energy consumption of courthouse buildings. In addition, this study investigated the total annual energy consumption (electricity, gas, and heating energy) per gross floor area of courthouse buildings located in the central and southern regions of South Korea. Although many studies about the energy consumption analysis of non-residential buildings have been performed previously, a study evaluating the effectiveness of green certification and building insulation thickness standard on the energy consumption of courthouse buildings was performed for the first time. The results revealed that the revision of building insulation thickness standard and G-SEED certification resulted in an energy consumption efficiency of 34.61 and 31.14%, respectively. These results indicated the effectiveness of G-SEED certification and the revision of the building insulation thickness standard for enhancing energy efficiency in Korean courthouse buildings. However, some negative results were observed in the southern area, indicating that it is essential to increase the effectiveness of the building insulation thickness standard and G-SEED certification implementation.

Multi‐stimuli‐responsive and Multi‐functional Smart Windows

AbstractSmart windows can change their optical characteristics according to environmental conditions or external stimuli (such as heat and electricity). They are manufactured by considering building characteristics, regional climate, energy policies, and indoor air conditions. Their key optical properties have been improved by developing novel materials, fabrication methods, and designs. The optical properties can be further improved by developing multi‐stimuli‐responsive smart window systems. Recently, some smart windows have been integrated with energy storage, solar energy harvesting, self‐cleaning, and air‐purifying functions. The energy consumed by buildings and houses accounts for a considerable portion of the total energy consumed by a country as well as the world; therefore, these state‐of‐the‐art smart windows will greatly contribute to saving energy. Moreover, some multi‐functional smart windows can help in addressing environmental challenges. This mini‐review particularly focuses on discussing the recent advances made in multi‐stimuli‐responsive and multi‐functional smart windows, in addition to summarizing the researches on electrochromic, thermochromic, and other types of smart windows.

Estimating unknown parameters of a building stock using a stochastic-deterministic-coupled approach

Interest in urban building energy modeling as a tool to evaluate effective management of urban building energy and carbon reduction policies is increasing. Since it takes a lot of time to model all buildings in the city with the lack of information about buildings, archetypes have been used. However, the deterministic method using archetypes does not reflect uncertainty with the disadvantage of not presenting design alternatives. To overcome such problems, we proposed an urban building energy modeling method using a stochastic-deterministic-coupled approach.In this paper, the identifiability of unknown parameters in a building stock was verified by analyzing the effect of the meta-model accuracy on the estimation of unknown parameters in the proposed urban building energy model. In addition, the possibility of using energy conservation measure analysis of the proposed model was evaluated.As a result, the posterior distribution of unknown input parameters was distorted when using the meta-model instead of the original building energy model in Bayesian calibration for building stock. However, the distorted posterior distribution could evaluate the effect of energy conservation measures within 0.71% errors.

Assessing building energy performance and energy policy impact through the combined analysis of EPC data – The Italian case study of SIAPE

Energy Performance Certificates (EPCs) and EPC digital registers are key tools to evaluate different aspects of the building stock and its energy consumption. This paper presents several detailed energy performance evaluations on the Italian buildings based on a sample of over 2,000,000 EPCs extracted from the national EPC register (SIAPE), contributing to the definition of an updated energy performance baseline of the Italian building stock. This is the first work using the Italian EPC register to define such a baseline to the extent of the authors’ knowledge. Furthermore, combined analyses of EPC data were carried out to obtain information on the influence of the Italian energy regulations on building characteristics and on the effectiveness of energy strategy application for building renovation.This study underlines the relevance of EPC registers and how the combined analysis of EPC parameters can provide a large amount of useful information on several aspects of the building stock, allowing the monitoring of the impact of the Italian energy policy framework on buildings energy performance. Finally, based on these results, the paper supports public authorities and decision-makers in planning and developing future energy programs and identifying the best practices on the Italian territory.

Strategic Building Energy Management, Policies, and Insulation Materials

Strategic Building Energy Management, Policies, and Insulation Materials

The regional disparity of per-capita CO2 emissions in China’s building sector: An analysis of macroeconomic drivers and policy implications

There are significant regional differences in CO2 emissions in China’s building sector. Analyzing and understanding this geographic inequality and its drivers is crucial for balanced regional development and greenhouse gas (GHG) emissions reduction. In this paper, we estimated the CO2 emissions of China’s building sector at the provincial level and then calculated the Theil Index of per-capita CO2 emissions generated from different building types. Based on these results, a Kaya identity was applied to analyze the drivers of the inequality in CO2 emissions across China. We found that the inequality index of the different types of buildings makes a significant difference. In general, the Theil Index for public buildings and urban buildings is higher than that for rural buildings. Income, energy intensity and energy mix are the principal drivers of regional disparity of per-capita emissions. Economic growth helps to narrow regional disparities for residential buildings, but its contribution is not significant for public buildings. For all building types, energy intensity is the primary contributor to emissions inequality, and the imbalanced implementation of energy efficiency policies is a leading factor. Energy mix plays an increasing role in the regional disparities of per-capita CO2 emissions, especially for rural buildings. Reducing these regional disparities is crucial to China’s goal of achieving peak GHG emissions and reaching carbon neutrality. This paper highlights the importance of per-capita CO2 emissions in formulating carbon peak planning, allocating regional emissions reduction targets, formulating building energy policies and allocating low-carbon resources.

Development and Verification of Prototypical Office Buildings Models Using the National Building Energy Consumption Survey in Korea

In the early 2000s, the Korean government mandated the construction of only zero-energy residential buildings by 2025 and for non-residential buildings from 2030. Two decades since the start of building energy policy enforcement, Korean experts believe that it is time to evaluate its impact. However, few studies have systematically and extensively examined the energy consumption characteristics of the non-residential building stock. In this study, a framework development is implemented for defining non-residential prototypical office buildings based on Korea’s first large-scale non-residential building survey result from the Korea Energy Economics Institute (KEEI). Then, a detailed building energy model of the defined prototypical building is constructed to verify the model’s energy estimation against observed energy consumption. As an application of the model, a case study for energy policy evaluation utilizing the constructed prototypical building model is presented. Every researcher and county may have their own circumstances when gathering definition data. However, by using the best available representative data, this suggested framework may result in informed decisions regarding energy policy development and evaluation. In addition, the mitigation of greenhouse gases from buildings may be expedited.

Social Network Analysis of Building Energy and Carbon Policy Networks in Developing Countries

More than two thirds of countries worldwide, the majority being developing countries still have not implemented mandatory regulations to control building energy usage and carbon emissions despite the rapidly increasing building stock in these regions. Thus, it is vital to develop effective energy and carbon policies for buildings in developing countries. Developing such effective policies in turn, needs well-structured policy networks consisting of efficiently connected key actors in policy implementation. A database search revealed significantly less progress in implementing the building energy and carbon policies in developing countries, compared with developed countries. Previous literature suggested Policy Network Analysis (PNA) as a powerful tool to assess current policy level actor coalitions, determine structural holes in stakeholder integration and decide on future policy improvements. Subsequently, a database search was carried out through the “Web of Science” publications repository to identify the previous PNA approaches and to identify a potential way forward. Among the available methods, Social Network Analysis (SNA) was identified as the most suitable and frequently used method which provides extensive analytical capabilities for policy network visualization and analysis. The preliminary findings lead to the novel SNA model that is proposed to map and assess required building energy and carbon policy networks which integrate both policy actors and constraints. This proposed model can be effectively utilized to identify the significance, centrality and relational structures of policy actors and policy constraints. This paper will benefit future researchers and relevant policy makers by providing an effective platform on which to further develop more effective energy and carbon policies for the building sector by strengthening stakeholder collaboration and integration.

Scenario Analysis for GHG Emission Reduction Potential of the Building Sector for New City in South Korea

A new government report on climate change shows that global emissions of greenhouse gases have increased to very high levels despite various policies to reduce climate change. Building energy accounts for 40% of the world’s energy consumption and accounts for 33% of the world’s greenhouse gas emissions. This study applied the LEAP (Long-range energy alternatives planning) model and Bass diffusion method for predicting the total energy consumption and GHG (Greenhouse Gas) emissions from the residential and commercial building sector of Sejong City in South Korea. Then, using the Bass diffusion model, three scenarios were analyzed (REST: Renewable energy supply target, BES: Building energy saving, BEP: Building energy policy) for GHG reduction. The GHG emissions for Sejong City for 2015–2030 were analyzed, and the past and future GHG emissions of the city were predicted in a Business-as-Usual (BAU) scenario. In the REST scenario, the GHG emissions would attain a 24.5% reduction and, in the BES scenario, the GHG emissions would attain 12.81% reduction by 2030. Finally, the BEP scenario shows the potential for a 19.81% GHG reduction. These results could be used to guide the planning and development of the new city.

Global comparison of building energy use data within the context of climate change

Building plays an important role in addressing climate change, with many studies on these topics having been conducted from a global perspective. However, building energy use is found to differ greatly among different countries, with the gaps yet to be fully considered or discussed. Thus, a picture of the overall situation in each country may be needed as a basis for global studies, and one of the first few steps to this end is to conduct a comparative study on energy use data. With these considerations, data related to building energy use are collected in this study from various resources. The energy use intensity, energy structure, and carbon emissions in different countries are compared using selected indicators and different projections were fitted presenting different development patterns. A new clustering of these countries is then proposed. Through the analysis, it could be found that countries with different phases of building energy development needs different patterns and the phase of each country based on global comparison could be some support for building energy policy and researches. Meanwhile, some suggestions on building energy data are discussed for a better understanding and evaluation of building energy use to better address climate change.