Building Energy Codes Research Articles

Sustainability framework of intelligent social houses with a synergy of double-façade architecture and active air conditioning systems

Social houses are built around the world to fulfill the basic needs of the growing population, especially middle-income families. Owing to the low budget available for such houses around the globe, necessary energy codes are often compromised. This research, through a methodological sustainability framework, presents the case study of Mexico with the objective to address this worldwide issue. More than 100,000 social houses were built in Mexico just in the year 2021 without strictly following any definitive building energy codes. Eventually, this is a ticking bomb, if left unaddressed, that can bring serious energy and environmental consequences connected with various social issues. Thus, as a research gap, the conventional 4E (energy, exergy, economic, and environmental) analysis cannot fully address such a complex energy-environmental-economic-social nexus. This work proposes an integrated sustainability framework of the practicability of the bioclimatic architecture of such a social house including energy, economic, environmental, and social assessment (novel addition to the analysis). The novel methodology is implemented on a novel technological advancement where double-façade architecture (i.e., solar chimney) is installed through a synergy and intelligent operation with an active air conditioning system including a desiccant enhanced air cooler and novel dew-point evaporative cooler. The article makes use of conventional physics-based modeling of thermal machines combined with an artificial neural network digital twin-based data-driven non-sorting genetic optimization of solar chimneys for various climatic conditions of Mexico. The optimal points are evaluated using annual climatic data to maintain the thermal comfort conditions and the results have suggested an increase of ∼48% through intelligent integration of double-façade architecture with the Maisotsenko cycle air cooler. Life-cycle economic assessment has suggested the Levelized cost of air conditioning be between 0.0096 and 0.0390 USD/kWh and can save up to ∼273 MXN per month with a real payback period of ∼8 years. Environment assessment has reported mitigation of up to ∼5668.59 kgCO2/year as compared to conventional vapor compression refrigeration systems. The social assessment is conducted on a pilot scale to directly ask the people of Mexico about their perception of the installation of the solar chimney while giving the fact that the initial price of the social houses can increase between 2.5 and 4%. It is reported that ∼62% of the sample is willing to install it even with a high price tag with a motive to initiate the climate change mitigation phenomena. The importance of the work has concluded that the government needs to take drastic and tough decisions to further regulate the energy efficiency in the social houses and limit the constructors to offer sustainable building construction.

Interface design for residential energy feedback, in the Indian context

Global access to electricity has increased from 78.2% to 2000 to 90.5% in 2020, resulting in an increased electricity demand worldwide. Unlike commercial electricity consumption, which is managed by professionals, residential consumption is managed by the householders, who often lack insight into their energy usage. Quality feedback, including detailed energy consumption and tips, can lead to substantial household savings. There are several mediums for providing energy feedback, such as Short Message Service (SMS), postal letter, email, mobile app, and In-Home Display (IHD). Studies suggest that feedback through electronic media can save up to 20% of energy consumption. In this work, we aim to design mobile application interfaces that can maximize energy savings through effective feedback. The level of savings realized is dependent on the user’s preferences and understanding of the information presented. User preferences are subjective of their profile (e.g., age, occupation, income) and the cultural context (e.g., country). The possibility of energy reduction is high when the provided information matches the user preferred information for feedback. Smart homes have recently been included as an annexure in India’s building energy code (Eco Niwas Samhita 2021), indicating a growing demand for quality energy feedback in India. However, there is a lack of research that addresses what feedback information is suitable for Indian users. We conducted two questionnaire-based surveys, one to understand users’ preferences for feedback information and another to validate the designed mobile application interface screens. The surveys were conducted on two age groups, young and middle-aged adults. A Chi-Square Test of Independence was performed to assess the relationship between the user’s preference for feedback information and their age group. Participants identified total energy consumption, appliance level disaggregated information, energy-saving tips, goals, and historical consumption comparisons as the top five information types. In contrast, normative comparison was the least preferred information. The follow-up design validations suggest that the interface should be customizable to accommodate the varying preferences of users. The current findings will help customize the energy feedback display UI design as per the Indian population.Graphical

The Double C Block Project: Thermal Performance of an Innovative Concrete Masonry Unit with Embedded Insulation

The Double C Block (DCB) is an innovative composite Concrete Masonry Unit (CMU) developed to offer enhanced thermal performance over standard hollow core blocks (HCBs). The DCB features an original design consisting of a polyurethane (PUR) foam inserted between two concrete c-shaped layers, thus acting as the insulating layer and the binding agent of the two concrete elements simultaneously. The purpose of this research is to describe the results obtained when assessing the thermal transmittance (UDCB and UHCB) of these blocks using three different methodologies: theoretical steady-state U-value calculations, numerical simulation using a Finite Element Method (FEM), and in situ monitoring of the U-value by means of the Heat Flow method (HFM). The results obtained show that the three methodologies corroborated each other within their inherent limitations. The DCB showed a performance gap of 52.1% between the predicted FEM simulation (UDCB was 0.71 W/(m2K)) and the values measured via HFM, which converged at 1.47 W/(m2K). Similarly, a gap of 19.9% was observed when assessing the HCB. The theoretical value via FEM of UHCB was 1.93 W/(m2K) and the measured one converged at 2.41 W/(m2K). Notwithstanding this, the DCB showed superior thermal performance over the traditional block thanks to a lower U-value, and it complies with the Maltese building energy code. Further improvements are envisaged.

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.

Hygrothermal Impacts of Building Energy Efficiency Measures: The Role of Evolving Building Energy Codes

Hygrothermal Impacts of Building Energy Efficiency Measures: The Role of Evolving Building Energy Codes

A Systematic Literature Review of Non-Compliance with Low-Carbon Building Regulations

Low-carbon building regulations are acknowledged as critical instruments to facilitate the building industry’s decarbonization transition. However, recent studies have shown that non-compliance with low-carbon requirements is under-researched, leading to a significant divergence between policy intentions and actual performance. In light of this, the paper aims to provide a synthesis of existing research on non-compliance with low-carbon building regulations. It does this using a systematic literature review combined with bibliometric and text mining techniques. Through reviewing 26 scholarly works from the last decade, the paper demonstrates a peak production year around 2015, the year of the Paris Agreement, with the USA and Australia as key countries of concern. Subsequently, the study reveals three focused research areas: the development of building policy during the low-carbon transition; the role of building energy performance requirements in achieving low-carbon buildings; and building energy code compliance. Findings suggest widespread non-compliance with building energy codes and also indicate influencing factors and associated enhancement strategies. Finally, the paper identifies gaps in the investigation of new forms of building energy codes; an inconsistent conception of compliance; and a lack of understanding in building practitioners’ compliance behavior. The study contributes to knowledge by providing future research areas in this under-researched topic and by successfully applying both bibliometric and text mining analysis in the construction management domain. This is found to have advantages in terms of time efficiency and objectivity. It also offers practical implications for industry by minimizing the gap between policy intentions and real compliance performance.

Improving the Thermal Performance of Building Envelopes: An Approach to Enhancing the Building Energy Efficiency Code

Cities on the east Mediterranean coast, especially in Palestine, are struggling to move towards sustainability as they are vulnerable to climate change and lack natural resources, especially energy resources, and this situation is further aggravated by high energy prices. The problem is the building sector, which is the most challenging sector when it comes to cities’ sustainability and, specifically, energy sustainability. In Palestine, this sector is the main consumer of energy but it lacks energy efficiency measures, such as up-to-date building energy codes. This study analyzed building thermal performance under different scenarios with a focus on building envelopes. We aimed to evaluate the benefits of introducing an updated building energy code—mainly addressing U-values for building envelopes—on future reductions in energy demand. We used a simulation tool (DesignBuilder) to evaluate typical existing building-envelope thermal and energy performances. Then, we undertook a comparison between the existing conditions and the proposed application of different scenarios, including the existing Palestinian building energy code and green building guidelines, the ASHRAE code for building envelopes, and the Jordanian building energy code, in order to introduce an updated building envelope energy code. The results showed that the current situation—building without applying any energy code or applying the existing Palestinian building energy code—is far from the high-energy performance that could be achieved by applying international or local green building codes. The use of thermal insulation could reduce the energy demand for heating by 83 to 43%, depending on the building type, climatic zone, and U-value. We recommend utilizing different U-values for building envelopes in different climatic zones to achieve high thermal performance. The results from this study have implications for construction industry professionals, local governments, and researchers seeking to establish high-energy-performance building envelopes.

Categorising the existing irradiance based blind control occupant behavior models (BC-OBMs) using unsupervised machine learning approach: A case of office building in India

This study aims to categorise the existing irradiance-based blind control occupant behaviour models (BC-OBMs) into distinct clusters of the same characteristics using an unsupervised machine learning approach. Fourteen BC-OBMs, including two base case models (blinds always opened – AL1 and always closed – AL2), have been simulated for an office building in Tiruchirappalli, India and categorised into three distinct clusters named: Passive open (C1), Passive close (C2), and Active (C3). C1 and C2 performed similarly to the base case models, AL1 and AL2, respectively. In contrast, C3 performed as an active cluster with a high number of blind movements (NBMs). This study also quantifies the degree of absolute error between the identified clusters and the base case model AL1 (as per the practice followed in Indian building energy codes) and emphasises the need to incorporate the BC-OBMs into the building energy codes to predict the artificial lighting consumption and lighting levels accurately. To the best of the authors' knowledge, this study is a novel attempt to categorise the existing irradiance-based BC-OBMs into distinct clusters. The research methodology adopted for this study can also be used in future research to categorise the window, artificial light, fan, and thermostat use OBMs into distinctive categories.

What, why and when to go virtual: An international analysis of early adopters of virtual building energy codes inspections

To meet greenhouse gas reduction targets, several countries are pursuing more ambitious policies in their buildings and construction sectors, such as introducing zero net energy/carbon building codes. Countries often report not having enough qualified staff for performing building energy code inspections and many are exploring faster, easier, and more reliable methods to check the compliance of buildings with their codes. Building inspections are a critical element for ensuring code compliance and they have traditionally been performed in person. However, in-person inspections can be labor and travel intensive, costly, and prone to human error. In this paper, the authors explore how virtual inspections, particularly in light of the recent COVID-19 pandemic, have impacted processes for building code compliance checks in jurisdictions and communities around the world. The authors collected data on four key parameters (time and financial savings, scope of inspections, changing practices and technological innovation, and benefits to consumers) from six jurisdictions and communities in five countries (Australia, Canada, Singapore, United Arab Emirates, and the United States) to analyze the impacts of virtual inspections on code compliance checks. The analysis found the greatest value from virtual inspections in geographically dispersed regions and for cities experiencing rapid building construction. The study also explored emerging technologies that are being piloted for virtual inspections. Although many of these technologies hold promise, more resources and capacity are needed to make them viable for use in building energy code inspections.

The impact of building energy codes evolution on the residential thermal demand

The building stock decarbonization by 2050 requires the implementation of an energy transition strategy. Building energy codes must be considered to minimize the energy consumption of the residential sector. This paper aims to evaluate the evolution of the building energy codes of Spain based on energy simulation. A quantitative assessment of the residential thermal demand according to the new energy efficiency requirements introduced in national regulations over the years was performed. Heating, cooling, and domestic hot water demands were assessed for 60 cases modeled in DesignBuilder, combining different building geometric typologies, energy codes, and climate zones. Heating presented the largest contribution to the total energy demand reaching up to 75%. The codes’ evolution led to a significant reduction in heating and a slighter decrease in cooling. The results showed an average energy demand improvement of 50% from the first regulatory release to the latest one.

An equitable energy allowance for all: Pathways for a below 2 [formula omitted]C-compliant global buildings sector

Buildings consume more than 30% of the world’s energy and are responsible for more than 28% of its energy-related carbon emissions. Despite the introduction of numerous energy codes, the sector is not ‘on-track’ to achieve its climate change target. To solve this, the paper asserts, energy codes must be derived from global climate change targets and consider the sector’s expansion. This paper introduces a novel global Building Stock Energy Model (BSEM) that realises that vision. Assuming a globally equitable annual building energy allowance per capita, the model determines, for the first time, the necessary energy efficiency levels for newly constructed and existing residential and non-residential building stocks of 138 countries, such that the sector’s climate change target is met. The results show that, to achieve that target whilst maintaining our ‘lavish’ lifestyle within buildings and continuing the sector’s expansion, extreme improvements in energy efficiency – greater than ever accomplished – are necessary. This has important policy implications in that it highlights the applicability and necessity of the ‘degrowth’ argument to the buildings sector. Moreover, the paper provides a valuable technical pathway around which building energy codes can be designed, where each of the 138 countries contributes its ‘fair’ share towards a below 2 °C-aligned global buildings sector.

Analytical process of the energy efficiency in building improvement alternatives

Thailand has set criteria called Building Energy Code (BEC) for building energy conservation). It is set OTTV as a standard value. Only the total amount of heat transferred through the walls in each direction of the building is considered. However, this approach cannot indicate the energy consumption needs and consider additional building improvement costs to meet the standard. This study presents the building improvement guidelines for reducing energy consumption by considering the changing construction costs to determine the efficiency of the cost’s impact and the changing energy values. These are the variables describing the interest for each alternative in terms of efficiencies and investment worthiness. Therefore, the building modelling created by Autodesk Revit and DesignBuilder is used to analyse the energy value, which needs calibration for Base Case Modelling. For the calibration, the past-3-year electricity consumption of the building is used, and the retroactive electricity value equals 55,920 kWh/year. In addition, comparing the energy consumption values obtained from the models, its value is 59,321 kWh/year, showing that the difference is only 5.73% before using the models to create the alternative cases. In this study, two alternative guidelines for decision-making of the building improvements are presented: (1) changing the building envelope from a single-layer to a double-layer brick wall, (2) adding the PU foam insulation and covering with gypsum board. The values of both alternatives regarding the effects on costs and changing energy consumption are 3.67 and 3.43 Wh/year/Bath, respectively. To conclude, the efficiency of the alternatives is quite similar, resulting in more remarkableness for the building improvement options. Thus, this can be used as a guideline for making decisions about building improvements in the future.

Study on thermal characteristics and electrical performance of a hybrid building integrated photovoltaic (BIPV) system combined with vacuum insulation panel (VIP)

Renewable energy systems are key technologies towards realizing reduced carbon footprint and sustainable architecture. Building integrated photovoltaics (BIPV) are renewable energy systems that function as integral building envelope components and simultaneously produce electricity. Not only is it essential to install BIPV for energy rebates, incentives or to cut down dependence on grid, but it is equally important that BIPV satisfies relevant building energy codes. Thus, thin high-performance insulation is needed to meet strict codes. Of all kinds of insulation materials presently available, vacuum insulation panel (VIP) has the highest thermal resistance per unit thickness. Therefore, VIP is a viable solution as an insulator for BIPV. In this study, the thermal characteristics and electrical performance of a hybrid BIPV module combined with VIP was investigated. The study is largely based on experiments carried out in a test building facility and supplemented with essential numerical simulations using Physibel BISCO/TRISCO building physics software. Data analysis was carried out for winter season. Results indicated that temperature at the back of the hybrid BIPV module (directly in contact with indoor air) was about 4 °C warmer than the heating setpoint temperature, which is advantageous for winter season. The maximum electrical efficiency was estimated to be 12.3 %. Compared to manufacturer specified electrical efficiency of 15 %, the peak efficiency realized is somewhat acceptable, factoring losses and winter weather conditions. Integrating BIPV and VIP yields an overall hybrid product that is compact and portable, and thermally more efficient from a building envelope perspective. As far as the authors know, this study is the first covering BIPV combined with VIP as a unitized module. Finally, current challenges and future research opportunities are explored.

Development of a Benchmarking Energy Performance Indicator (BEPI) monitor for existing traction lift systems

Energy consumption of lift systems is one key issue in modern high-rise buildings, drawing property owners’ attention and accounting for 6% of total electricity consumption by end-use in Hong Kong. A Benchmarking Energy Performance Indicator (BEPI), <J/kg-m>, measured in J.kg−1.m−1 and proposed by the first author of this paper for lift installations is mentioned in the Technical Guidelines of the Building Energy Code, as one emerging good engineering practice. BEPI is a fair parameter for comparing energy performance of lifts irrespective of their brand, model, travel, speed, capacity and control. It considers energy performance due to both the motor drive efficiency and traffic control intelligence. However, one main obstacle to make it statutory is the lacking of a generic monitor able to retrieve three sets of real time data (normally unavailable on an existing lift) to compute the BEPI, namely energy consumption, instantaneous car load and traveling distance, and to collect ample data statistically reliable enough to determine an acceptable threshold value. This paper describes the development of a proof-of-concept prototype BEPI monitor by giving full technical details on the rationale and history of development, the hardware components, software framework, and updated numerical results of one implementation inside the headquarters of Electrical & Mechanical Services Department (EMSD) of HKSAR. Experiences in installing and calibrating those external sensors that make the whole system non-disturbing to normal lift operation, as well as the procedures in computing the BEPI, are discussed in greater details. It has been shown that the BEPI is traffic dependent but the weekly average of it is relatively stable, confirming it may be robust enough for benchmarking purpose. The solution described in this paper may help roll out the monitoring of BEPI for all lifts inside and outside Hong Kong.

Development of Simplified Building Energy Prediction Model to Support Policymaking in South Korea—Case Study for Office Buildings

This study aims to support building energy policymaking for office buildings in South Korea through regression models by considering the global temperature rise. The key variables representing building energy standards and codes are selected, and their impact on the annual energy consumption is simulated using EnergyPlus reference models. Then, simplified regression models are built on the basis of the annual energy consumption using the selected variables. The prediction performance of the developed model for forecasting the annual energy consumption of each reference building is good, and the prediction error is negligible. An additional global coefficient is estimated to address the impact of increased outdoor air temperature in the future. The final model shows fair prediction performance with global coefficients of 1.27 and 0.9 for cooling and heating, respectively. It is expected that the proposed simplified model can be leveraged by non-expert policymakers to predict building energy consumption and corresponding greenhouse gas emissions for the target year.

Municipal Greenhouse Gas Emission Reduction Targets: The Role of Building Energy Regulations and Laws

Buildings are the single largest user of energy in the US and can account for 50%–75% of carbon emissions in large cities. Adopting effective regulations for encouraging more energy-efficient buildings is therefore paramount. Besides the voluntary programs, the regulatory bodies (e.g. municipalities) have different mandatory programs to motivate energy efficiency in new and existing buildings. While building energy codes and auditing are traditional law instruments, an increasing number of cities across the US have adopted building energy benchmarking laws in recent years. This study evaluates the building energy regulations and laws in seven US cities. In particular, it focuses on three major aspects of the building energy laws for each city: (1) scope and compliance, (2) implementation and enforcement, and (3) contribution to the emission reduction. The results show that although energy codes are necessary to establish minimum requirements for new buildings, adopting mandatory benchmarking and transparency laws can significantly reduce energy use. The study concludes with a comparison of adopted energy laws in selected cities and discusses the factors affecting the successful adoption of benchmarking policies such as compliance rate and training of building owners. The results of this study can raise the awareness of policymakers for implementing more effective building energy regulations.

Analysis on building envelope and building service equipment design specification using the input and output data from the calculation program to confirm compliance with building energy code (part 1): Identification of the design specification for newly built offices in Japan according to the evaluation result of the building energy code

AbstractIt is essential to clarify the actual design specifications of buildings to plan future energy conservation measures. This paper focuses on the single‐purpose office buildings built in the financial year of 2018 and analyses the data on building envelope and equipment specifications from the calculation program to confirm compliance with the building energy code. This paper shows that the office buildings can be classified into five groups according to the evaluation index of the building energy code and identifies the standard design specifications of building envelope, air‐conditioning system, lighting system, and solar power generation for each group.

Compliance with Building Energy Code for the Residential Sector in Egyptian Hot-Arid Climate: Potential Impact, Difficulties, and Further Improvements

Building energy codes are considered to be an effective policy tool for energy reduction worldwide. However, their application and effectiveness are still limited in developing countries. In Egypt, the residential sector is promising for energy savings, as most of the existing residential buildings are aged with low thermal performance and non-conformance with energy codes. This study aims to raise the awareness of promoting the Egyptian residential energy codes among construction parties, especially end-users, by quantifying the environmental impacts, in terms of energy savings and thermal comfort enhancement. Moreover, it attempts achieving a nearly zero energy building by integrating several energy-efficient measures with renewable energy sources. Thus, in this study, a typical residential building in Cairo was chosen for simulation. The simulation results revealed that applying energy code instructions for building envelope, lighting enhancement and increases in cooling set-points, from 24 °C to 25 °C, saved 37.85% of annual electrical energy and resulted in a cooling reduction of 50.53%. Furthermore, the photovoltaic system incorporation succeeded in transforming the building into a nearly zero energy building. Concerning thermal comfort, the application of passive energy-efficient measures significantly influences indoor thermal comfort, with a 30% reduction in discomfort hours during the cooling season, which represents the main concern in hot climate regions.

Research on Optimization of the Thermal Performance of Composite Rammed Earth Construction

Rammed earth (RE) is a low-tech recyclable building material with good heat storage and moisture absorption performance that can better maintain the stability of the indoor thermal environment and improve indoor comfort. With innovations in and the development of new technology, the field of rammed earth construction technology is gradually expanding. However, deficiencies in the thermal insulation of traditional rammed earth structures make it impossible for them to meet China’s building energy codes in cold regions. This study constructs a comprehensive evaluation index of the thermal performance of rammed earth walls that is based on the heat transfer mechanism, optimizing the thickness of the boundary conditions of the building interior’s design temperature, as well as the energy demand and economic efficiency. This research also offers a new design for the thermal insulation of rammed earth construction by combining the building energy savings design code with WUFI Pro software. This study demonstrates that the optimum thickness of rammed earth construction in Beijing is about 360 mm, the thickness of extruded polystyrene board (XPS) is 50 mm (for public buildings) and 70 mm (for residential buildings), and the structural form of external insulation offers the highest performance benefit. In addition, this work also evaluates the risk of condensation inside composite rammed earth construction, finding that there is a risk of condensation on the exterior side of the wall and at the interface between the insulation panels and rammed earth wall, thus requiring an additional moisture-proof layer. In this study, thermal mass and insulation are fully considered and a design strategy for rammed earth construction given quantitatively, providing a theoretical basis for the application of rammed earth materials in cold regions.

Thermally Comfortable Affordable Housing: A Study on Residential Building Code In India

On an average, India has more than 3000 Cooling Degree Days (CDD). The multifamily public housing being constructed under India’s Prime Minister Awas Yojana (PMAY) is aimed at providing formal housing to the society’s Economic Weaker Section (EWS). It is essential that this housing delivers thermally comfortable in-doors to the occupants. This study mapped the design and construction practices followed under PMAY Urban (PMAY-U) against India’s Residential Energy Building Code, Eco Niwas Samhita (ENS). The metric prescribed in ENS is Residential Envelope Transmittance Value (RETV). For 80 PMAY-U projects, information related to spatial design, and walling assemblies was collated. 30 projects were short-listed for detailed analysis. The RETV for selected projects was calculated. The analysis demonstrated that walling assemblies and technologies having a lower thermal transmittance value (U-value) resulted in meeting the ENS prescribed RETV numbers, hence, code compliance. The study further extended to assess the energy performance of the housing unit by exploring the change in walling assemblies. The change in thermally comfortable hours were reported in the range of 4145 and 6034, and Energy Performance Index (EPI) of the dwelling units were reported between 64 and 68 kWh/m2/year for the various walling assemblies.