Greenhouse Gas Emissions Of Buildings Research Articles

Analyzing the impact of using phase change materials on energy consumption in buildings: A case study

The use of phase change material (PCM) in buildings has been shown to be a promising method for reducing energy consumption. This study investigates the effectiveness of using PCM in reducing energy consumption in a typical residential building located in Podgorica, Montenegro, a city with mild winters and hot and dry summers. EnergyPlus software was used to simulate the thermal performance of a building with and without the incorporation of PCM. Building models were created in a way to incorporate PCM in form of a panel, and simulations were done with five different types of PCM, five different thicknesses and three different positions (outside, inside and middle of building envelope). The simulations were performed over a one-year period to account for seasonal variations in temperature and humidity. The simulation results indicate that the use of PCM in buildings design can significantly reduce energy consumption in buildings located in climates similar to Podgorica. This approach can also lead to a reduction in greenhouse gas emissions associated with energy consumption. These findings provide valuable insights for building designers and policymakers looking to reduce energy consumption and improve the sustainability of buildings. In conclusion, the results of this study support the use of PCM in building design as an effective strategy for reducing energy consumption and greenhouse gas emissions in buildings. Further research is needed to investigate the cost-effectiveness of using PCM in buildings design and to explore the potential for their widespread implementation.

Development of a comprehensive method to estimate the optical, thermal and electrical performance of a complex PV window for building integration

Increasing concerns over energy consumption and greenhouse gas emissions in buildings have contributed to the emerging of innovative PV glazing technologies to improve the building energy performance. However, some of these glazing systems have complex structures, making it challenging to investigate their optical, thermal and electrical performance for estimating their energy saving potential in buildings. In this research, a validated Computational Fluid Dynamics (CFD) combined with a ray-tracing model has been developed to accurately predict the optical, thermal and electrical performance of complex PV glazing systems under varying incident angles. A ray-tracing model is developed to calculate the light transmittance of the window and the solar energy absorbed by each solid element and PV cells. To estimate temperature profiles (e.g., PV temperature and window temperature) and secondary heat within the window, the results from the ray-tracing analysis, which detail the solar flux absorbed by each layer, are inputted into a validated CFD model as boundary conditions. Using the CFD combined ray-tracing calculation illustrated above, the Solar Heat Gain Coefficient (SHGC) of these complex PV window systems can be obtained. Furthermore, a PV modelling algorithm is developed to predict the power output based on the simulated PV temperature. This procedure is implemented to investigate a Crossed Compound Parabolic Concentrator Photovoltaic (CCPC-PV) window, which serves as an example of a complex PV glazing system in this study. The developed optical, thermal and electrical models have been validated through experimental tests. Additionally, new configurations have been designed to explore the impact of the pitch between adjacent optics on the SHGC and power output of the window. The results show that the original window (1.77 mm-pitch) possesses the maximum PV temperature of 64.73 °C and the maximum window inside surface temperature of 61.58 °C under National Fenestration Rating Council (NFRC) standard. Meanwhile the PV efficiency is 15.21 % and the SHGC is 0.463. The SHGC value of this innovative PV window is notably lower than that of a conventional double-glazed window, which has a SHGC value of 0.813. This reduction in SHGC decreases the likelihood of overheating issues, especially during the summer months.

Structural design of hybrid steel-timber buildings for lower production stage embodied carbon emissions

Using cross laminated timber (CLT) floor panels in combination with steel framing has been identified as a promising new structural configuration that can reduce the embodied greenhouse gas emissions of buildings. This project evaluated efficient structural design of hybrid steel-timber floor sections for a wide range of design parameters to determine the reductions in global warming potential possible relative to a conventional steel-concrete cross section. Each of the structural designs was checked for strength limit states, deflection, and minimum fire rating of either unrated, 1-h, or 2-h for a range of deck spans between 2.3 m and 4.6 m and beam spans between 5.5 m and 13.5 m. For an unrated floor assembly there is little global warming potential benefit to use steel-timber floors if a topping slab is included on top of the CLT slab. Whereas, using steel-timber configurations without a topping slab result in the largest global warming potential reductions. For the 1-h and 2-h ratings, even steel-timber configurations with a 64 mm thick topping slab had up to 20% reduction in global warming potential compared to the steel-concrete alternative. Additionally, several considerations that can drastically affect the global warming potential results were discussed. The results from this project demonstrate the best practices for structural design of hybrid steel-timber buildings to reduce global warming potential of the superstructure frame by between 5% and 35% relative to conventional steel and concrete construction.

The buried giant: Construction materials shape the environmental footprint of buildings

The environmental impacts, including those related to greenhouse gas emissions, of the construction and deconstruction of buildings come more and more into focus of governments and professional building owners. In new constructions these so-called embodied impacts are often more important than the environmental impacts during 50 years use phase. How did the environmental impacts caused by construction materials and building technologies and their supply chains change during the past three decades? What might be expected in the future? How did LCA contribute to the past development and how did LCA practice evolve during this period? Finally, are current LCA practices suited to support the transformation of the building stock towards net zero greenhouse gas emissions?In a first part, the past as well as the potential future development of the environmental impacts caused by the manufacture of selected key construction materials and their supply chains will be presented. The main measures which lead to lower impacts in the past and which will be needed to further reduce environmental impacts in the future will be named. Current trends will be assessed against their effectiveness to reach net zero greenhouse gas emissions of buildings and the built environment.In a second part the history and evolution of LCI data collection and data management will be discussed. Several aspects will be covered such as information sources, modelling and methodology, environmental impacts (pollutants and resources) covered in the LCIs, IT resources and solutions, and information policies.

Future trends in materials manufacturing for low carbon building stocks: A prospective macro-scale analysis at the provincial level

In order to reduce the greenhouse gas (GHG) emissions of buildings, the literature has investigated many strategies to tackle operational emissions, which are traditionally the largest contributor to overall emissions. As a result, embodied emissions are gaining increased attention, not only due to the decrease in the relative share of operational emissions but also due to increased material needs, e.g. the use of additional thermal insulation in buildings. Some of these strategies, such as the decarbonisation of the energy grid, could also help decrease the embodied emissions of building materials. The objective of this paper is to investigate the influence of increased renewable electricity use in building material production. It also examines future trends in the manufacturing processes – such as an intensified use of bioenergy, improvements in energy efficiency and the introduction of carbon capture and storage – on the GHG emissions of buildings. These strategies are analysed in a combined “future materials” scenario on a macro scale within the Tyrol province in Austria. With a focus on new residential constructions, six design variations of two building case studies are assessed using life cycle assessment. They are then projected to 2050 at the provincial level. The results of the future materials scenario point towards a promising embodied GHG reduction, up to 19% in this analysis. Larger mitigation effects would appear in the 2040s and 2050s, meaning future manufacturing technologies can be seen as a long-term investment. Their reduction potential surpasses the potential impact of an increase in wooden constructions. The latter achieved up to 7% reduction in GHG emissions, which would be mostly visible in the early decades rather than in later ones. These reduction percentages remain lower than those which could be attained at the operational energy level, with reductions of up to 72%. The obtained results are discussed in the light of other published regional and global studies to identify the possible sources of variations. Critical reflections on carbon capture and storage, as well as renewables, additionally highlight the intrinsic challenges of such key technologies.

Impact of Energy Efficient Design Strategies on Users Comfort in Selected Mixed-Use Buildings in Lagos State, Nigeria

Human comfort is a major criterion for mixed-use buildings to be habitable, leading to the usage of technologies such as HVAC and artificial lighting. These devices demand high electricity, causing a 25% rise in building greenhouse gas emissions. It is important for architects to develop energy efficient design strategies in order to maintain and improve user comfort in mixed-use buildings. This study investigated the impact of energy efficiency design strategies on users’ comfort in selected mixed-used building in Lagos State, Nigeria, with a view to identify areas for further improvements. The research adopted a quantitative approach. A structured questionnaire was used to obtain data. The Statistical Product & Service Solutions software was used to analyse the data. The result was presented with the aid of texts, tables and graphs. The findings indicated that building orientation was one of the most important techniques, affecting each dimension of human comfort. This revelation suggests that when adopting energy efficiency measures, a building’s early design stage should focus on enhancing human comfort. The study recommended that professionals conduct critical analysis on buildings in the design stage to guarantee energy-efficient approaches used throughout the planning, design, and construction stages of mixed-use buildings. In order to create sustainable future designs, it is therefore necessary to recognise the significance of energy efficient design techniques on users’ comfort.

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

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

A review of existing policy for reducing embodied energy and greenhouse gas emissions of buildings

The building sector is a significant contributor to global energy demand and greenhouse gas emissions and thus has a major role in combating climate change. To date, efforts to address this issue have focussed on reducing energy demand during building operation, resulting in significant reductions in this area. However, recent studies have shown that substantial improvements to operational energy efficiency have increased the relative significance of indirect or embodied energy demands and associated greenhouse gas emissions. Subsequently, policies addressing this next frontier of energy and emissions reductions are emerging. To understand different approaches and inform future development, this study reviews existing policy mechanisms targeting embodied energy and greenhouse gas emissions in the building sector for four countries – Australia, Canada, USA and United Kingdom. The study found that voluntary instruments dominate the policy landscape, with regulatory measures largely absent at national levels and confined to inconsistent application across lower levels of governance. Signals of change emerging from the analysis include growing private sector investment and increasing quantitative targets for reduction. The study concludes with the challenges facing this sector of energy governance, alongside recommendations for regulated caps, mandatory LCA reporting, prerequisite requirements in voluntary instruments, data accessibility and resolving methodological inconsistencies.

A Study of Energy Utilization and Carbon Emission Audit of a Commercial Mall in Hot Summer/Warm Winter Region in China

Evaluation on the carbon emissions of large public buildings and carbon reduction measures are very important to help reach carbon peak demand and carbon neutral. The purpose of this study is to conduct energy audits and energy-saving assessments on large public and commercial buildings to find out the impact of various behavioural activities related to buildings on carbon emissions and energy consumption, and to explore the carbon reduction potential of buildings. In China, the energy structure based on fossil fuels will not change in a short term, and energy consumption will inevitably increase with economic development; however, the energy efficiency is the main factor that affects the building carbon emissions. And changing energy efficiency will reduce emissions by 9.29%, while improving the energy structure will reduce emissions by only 0.46%; it is the key work to slow down greenhouse gas emissions in buildings that is reducing power consumption of electrical equipment, especially the air-conditioning system, which can result in 49.72% energy saving after reforming.

Impacts of green certification programs on energy consumption and GHG emissions in buildings: A spatial regression approach

For better energy assessment and management in the buildings industry, a spatial regression method is presented to quantitively measure the impacts of green certification programs on energy consumption and Greenhouse Gas (GHG) emissions in buildings. Spatial autocorrelation analysis is developed to determine the spatial pattern of energy consumption and GHG emissions. A Gaussian kernel function method is employed to calculate the spatial weighting matrix, and an Akaike Information Criterion method is implemented to choose the function bandwidth in the spatial weighting matrix. Subsequently, a geographically weighted regression (GWR) model based on the spatial weighting matrix is constructed to estimate energy consumption and GHG emissions in buildings. Several error criteria are employed to verify the development of the GWR model compared with the ordinary least square (OLS) model. Regression coefficient, Pearson correlation coefficient, and Spearman correlation coefficient analyses are implemented to investigate the effects of green certification programs on building energy consumption and GHG emissions. A case study in Seattle city in 2015 is used to implement the GWR model and validate the improved goodness-of-fit of this regression model. The results imply that: (1) Energy stars programs as the driving force would save energy consumption by 13.2% on average and reduce GHG emissions by 3.24% on average; (2) The fitted GWR models can significantly improve the model’s goodness-of-fit and accuracy with an adjusted R2 value of 0.572 in modeling energy consumption and that of 0.626 in modeling GHG emissions compared with the OLS models (with an R2 of 0.538 and 0.594, respectively); (3) Older buildings, taller buildings, and larger buildings with energy star labels have been demonstrated to have a big potential to significantly save more energy and reduce more GHG emissions. This spatial regression approach can be used as an assessment tool for professionals and authorities to detect the influence factors on energy consumption and GHG emissions in buildings and make environmentally sustainable plans for buildings in cities.

Embodied GHG Emissions of Wooden Buildings—Challenges of Biogenic Carbon Accounting in Current LCA Methods

Buildings play a vital role in reaching the targets stated by the Intergovernmental Panel on Climate Change to limit global warming to 1.5 degrees. Increasing the use of wood in construction is a proposed upcoming strategy to reduce the embodied greenhouse gas emissions of buildings. This study examines existing life cycle assessments of wooden buildings. The aim is to investigate embodied greenhouse gas emission results reported, as well as methodological approaches applied in existing literature. The study applies the protocol for Systematic Literature Reviews and finds 79 relevant papers. From the final sample, the study analyses 226 different scenarios in-depth in terms of embodied emissions, life cycle assessment method, life cycle inventory modelling and biogenic carbon approach. The analysis shows that the average reported values of embodied greenhouse gas emissions of wooden buildings are one-third to half of the embodied emissions reported from buildings in general. Additionally, from the analysis of the final sample we find that the majority of wooden building life cycle assessments apply similar methods and often leave out biogenic carbon from the assessment or simply do not declare it. This implies that the focus on variability in the different methods applied in wooden building life cycle assessments needs to be increased to establish the relationship between methodological choices and embodied emissions of wooden buildings. Further, transparency and conformity in biogenic carbon accounting in life cycle assessments is essential to enhance comparability between life cycle assessment studies and to avoid distortions in embodied GHG emission results.

Regional variation of greenhouse gas mitigation strategies for the United States building sector

In this study, the impacts of various mitigation strategies for existing and newly constructed buildings in the United States on embodied and operational greenhouse gas (GHG) emissions were quantified until 2050. A bottom-up approach was utilized to model the characteristics of individual reference buildings. First, reference designs and practices were developed for climatic regions across the United States to capture spatial variation in energy demand, building codes, and structural performance. Then, the results were scaled up to regional networks (at county and state levels) and finally to the entire country. Given the fact that mitigation strategies can vary by region and building type, we explored the key drivers of impacts in the buildings sector and prioritized which strategies should be applied in different regions and building types. To meet deep decarbonization goals, we will need to pursue strategies for GHG emissions reductions in both the embodied and operational phases of the building life cycle. We found there will be no meaningful reduction in building GHG emissions in the Western US and New England regions under current projected technology and code improvements because they are on the leading edge of emissions reduction strategies. However, there is much more opportunity to lower life cycle GHG emissions in the Midwest and central US regions because they are further behind the implementation of reduction strategies. A number of interventions—chiefly to the electricity grid, appliances, and lighting—could nearly halve the emissions of new buildings constructed between 2016 and 2050.

Building Retrofit and Energy Conservation/Efficiency Review: A Techno-Environ-Economic Assessment of Heat Pump System Retrofit in Housing Stock

The world has not been able to achieve minimum greenhouse gas emissions in buildings’ energy consumptions because the energy and emissions optimization techniques have not been fully utilized. Thermal comfort is one of the most important issues for both residential and commercial buildings. Out of the 40% of global energy consumed by buildings, a large fraction is used to maintain their thermal comfort. In this study, a comprehensive review of the recent advancements in building energy conservation and efficiency application is presented based on existing high-quality research papers. Additionally, the retrofit of the heating/cooling and hot water system for an entire community in Cyprus is presented. This study aims to analyze the technical and environmental benefits of replacing existing electric heaters for hot water with heat pump water heating systems and the use of heat pump air conditioners for thermal comfort in place of the existing ordinary air conditioners for space heating and cooling. One administrative building, 86 apartments (including residential and commercial) buildings, and a restaurant building is retrofitted, and the feasibility of the project is determined based on three economic indicators, namely; simple payback period (SPP), internal rate of return (IRR), and net present value (NPV). The electrical energy required by the hot water systems and the heating/cooling system is reduced by 263,564 kWh/yr and 144,825 kWh/yr, respectively. Additionally, the retrofit project will reduce Cyprus’ CO2 emission by 121,592.8 kg yearly. The SPP, IRR, and NPV for the project show that the retrofit is economically feasible.

Natural ventilation usability under climate change in Canada and the United States

ABSTRACT Natural ventilation can be incorporated into buildings to decrease energy use and the associated greenhouse gas emissions of buildings. However, mechanical cooling has largely replaced natural ventilation in commercial buildings in Canada and the US. This study evaluates the potential for natural ventilation under climate change. To this end, a typical office space in a mixed-mode building in 14 cities representing the major climate zones in Canada and the US was simulated to assess the usability of natural ventilation under the predicted climatic data for the years 2050 and 2080. A rule-based model for change-over between natural and mechanical ventilation modes was developed on the basis of the adaptive thermal comfort model. The potential impact of occupants was also simulated using an existing stochastic occupants’ window use model. The simulation results show that the natural ventilation usability with rule-based control generally decreases under climate change. The stochastic model indicated the risk of overheating resulted from inefficient window use. Climate change leads to higher cooling energy use, which can be reduced considerably, especially in temperate climates, using natural ventilation with rule-based control. However, the stochastic model yielded to the reduction in the energy saving rates.

Energy Efficiency and GHG Emissions Mapping of Buildings for Decision-Making Processes against Climate Change at the Local Level

Buildings have become a key source of greenhouse gas (GHG) emissions due to the consumption of primary energy, especially when used to achieve thermal comfort conditions. In addition, buildings play a key role for adapting societies to climate change by achieving more energy efficiency. Therefore, buildings have become a key sector to tackle climate change at the local level. However, public decision-makers do not have tools with enough spatial resolution to prioritise and focus the available resources and efforts in an efficient manner. The objective of the research is to develop an innovative methodology based on a geographic information system (GIS) for mapping primary energy consumption and GHG emissions in buildings in cities according to energy efficiency certificates. The developed methodology has been tested in a representative medium-sized city in Spain, obtaining an accurate analysis that shows 32,000 t of CO2 emissions due to primary energy consumption of 140 GWh in residential buildings with high spatial resolution at single building level. The obtained results demonstrate that the majority of residential buildings have low levels of energy efficiency and emit an average of 45 kg CO2/m2. Compared to the national average in Spain, this obtained value is on the average, while it is slightly better at the regional level. Furthermore, the results obtained demonstrate that the developed methodology is able to directly identify city districts with highest potential for improving energy efficiency and reducing GHG emissions. Additionally, a data model adapted to the INSPIRE regulation has been developed in order to ensure interoperability and European-wide application. All these results have allowed the local authorities to better define local strategies towards a low-carbon economy and energy transition. In conclusion, public decision-makers will be supported with an innovative and user-friendly GIS-based methodology to better define local strategies towards a low-carbon economy and energy transition in a more efficient and transparent way based on metrics of high spatial resolution and accuracy.

Ten questions on urban building energy modeling

Buildings in cities consume up to 70% of all primary energy. To achieve cities’ energy and climate goals, it is necessary to reduce energy use and associated greenhouse gas emissions in buildings through energy conservation and efficiency improvements. Computational tools empowered with rich urban datasets can model performance of buildings at the urban scale to provide quantitative insights for stakeholders and inform their decision making on urban energy planning, as well as building energy retrofits at scale, to achieve efficiency, sustainability, and resilience of urban buildings.Designing and operating urban buildings as a group (from a city block to a district to an entire city) rather than as single individuals requires simulation and optimization to account for interactions among buildings and between buildings and their surrounding urban environment, and for district energy systems serving multiple buildings with diverse thermal loads across space and time. When hundreds or more buildings are involved in typical urban building energy modeling (UBEM) to estimate annual energy demand, evaluate design or retrofit options, and quantify impacts of extreme weather events or climate change, it is crucial to integrate urban datasets and UBEM tools in a seamless automatic workflow with cloud or high-performance computing for users including urban planners, designers and researchers.This paper presents ten questions that highlight significant UBEM research and applications. The proposed answers aim to stimulate discussion and provide insights into the current and future research on UBEM, and more importantly, to inspire new and important questions from young researchers in the field.

Integrating climate change in life cycle assessment of buildings: literature review

The operational energy use and related greenhouse gas emissions of buildings are typically influenced by changes during the building service life such as climate change, technological evolution and energy mix evolution. Only few LCA studies consider these temporal variations. This paper investigates how climate change is currently considered in LCA studies. Three aspects related to the influence of climate change on the life cycle impact of buildings are focused on: (1) changes in operational energy use (heating and cooling) due to changes in the climatic context of the building, (2) changes in operational energy use due to technological evolution or climate regulations and (3) changes in energy mix due to climate regulations. All three influence the energy use and related environmental impact but the extent of the effect depends on the considered region, time step and environmental indicators. It is hence recommended to choose an appropriate time period when considering climate change in LCA and consider variations within a time period via dynamic building simulations or to include a static correction. A holistic set of impact categories should be focussed on to avoid burden shifting and the most influencing parameters should be checked via a sensitivity analysis.

Mitigation Strategies for Reduction of Embodied Energy and Carbon, in the Construction Systems of Contemporary Quality Architecture

The criticality related to the consumption of operational energy and related greenhouse gas (GHG) emissions of existing buildings is clearly decreasing in new buildings due to the strategies tested and applied in recent years in the energy retrofit sector. Recently, studies have been focusing on strategies to reduce environmental impacts related to the entire life cycle of the building organism, with reference to the reduction of embodied energy (and related greenhouse gas emissions) in building materials. As part of EEA’s European EBC project, Annex 57, a wide range of case studies have been promoted with the aim of identifying design strategies that can reduce the embodied energy and related greenhouse gas emissions of buildings. The aim of this paper is to investigate the most common construction systems in the construction industry (concrete, steel, wood) through the analysis of three contemporary architectural works, with the aim of identifying the predisposition for environmental sustainability of each technological system, thus guiding the operators in the sector towards design choices more compatible with the environmental requirements recommended by European legislation.

A validated low carbon office building intervention model based on structural equation modelling

Building energy performance in existing stocks via facilities management interventions for low carbon building has become expedient and relevant in global climate change discourse. It has raised the consciousness for the need for a unified decision-support model for Facilities Managers and Owners, which could be used for office buildings across countries in achieving cleaner building energy production and use. This paper aimed at examining the factors that affect office Building Energy Performance; their interdependencies; and identify the critical path for interventions. It filled this gap by presenting a combination of interrelated processes (operations, tactics, and strategies) needed to improve building energy performance, reduce costs and greenhouse gas emissions in buildings for organizations. An online questionnaire survey was used in gathering data on current study model variables from participants of case study office buildings in Nigeria and the UK. Structural Equation Modelling technique was used to examine the factors that contribute to improving the energy performance of heterogeneous office buildings in both countries. The result established a strong correlation among observed variables and constructs and high covariance between constructs. This indicates that dependency and interdependence relationships exist amongst constructs, and in between construct and indicators. The finding reveals that an organization needs Sustainability Policy, Facilities Management and Energy Management as a sub-set of Strategic policy incorporated into its core management policy and operations energy management to achieve low carbon building. It also reveals the most critical pathway in the overall model with Strategic Facilities Management discovered to underpin the optimal performance for office buildings.

Study on the Improvement of Expected Energy Savings and Actual Energy Savings in Apartments

Regulating energy consumption can reduce both greenhouse gas emissions and expenditures. In order to maximize efficiency, appropriate energy protocols for buildings must be devised and implemented. This study examines predicted and real energy savings, the differences between them, and the methods which might reduce these discrepancies. Analyses for 195 high-efficiency apartment units (certified based on the energy efficiency rating system in use in Korea) indicated an average difference of 23% between predicted and real energy savings. This was found to be due to the fact that predictions failed to take variables such as Heating Type, Corridor Type, and Climate into account. By accounting for these factors, an appropriate calculation formula may be established. Using the revised calculation formula to reevaluate the predicted energy savings of 13 apartment units resulted in a reduction of 7% in the aforementioned discrepancy between predicted and real energy savings. Using the proposed formula to predict energy savings in buildings could improve accuracy, thus facilitating the setting of appropriate standards for restrictions on greenhouse gas emissions of buildings.