Search Results (11)

Energy accounts for a significant share of carbon emissions, and buildings play a substantial role in this by contributing to both direct and indirect emissions throughout their lifecycle. Enhancing energy efficiency in buildings is a strategy to mitigate these impacts. The main goal of this review is to uncover solutions, trends, and examples of good practices in the field of office buildings. It presents effective cases and a SWOT analysis of LEED, BREEAM, and DGNB certifications, highlighting their contributions to energy efficiency in buildings on an international scale. The paper identifies and outlines similarities and differences between each methodology used to achieve energy efficiency in different buildings and contexts. The findings may allow new ways to improve access and obtain results regarding energy efficiency, thereby supporting building owners and companies in finding more effective solutions. The research highlights the necessity for continual enhancements in these systems, which should involve addressing economic factors, conducting post-occupancy evaluations, and considering lifecycle perspectives. The recommendations encompass standardizing practices, considering costs, conducting regular revisions, managing materials and resources, and incorporating occupancy measures. Full article

This study summarizes the technology level and economic feasibility of two small 500 m² public office buildings that achieved a first-class Zero Energy Buildings (ZEB) certification for the first time in Korea. In addition, a Life Cycle Assessment (LCA) reflecting the ZEB performance in the operation stage was analyzed, and the LCA factors considering the characteristics of small buildings were reviewed. Moreover, an economic analysis was performed through a Net Present Value (NPV) by reflecting the ZEB and LCA, and the results showed little economic feasibility. However, adding the environmental costs calculated through the LCA to the existing energy-saving costs could offset an additional 11.6–11.7%. Therefore, including the environmental impact and cost through these LCA evaluation techniques could be a positive step toward increasing the effectiveness of ZEB applications. This study is significant in that it conducted a comprehensive analysis through ZEB and LCA in terms of carbon reduction for small buildings that achieved a first-class ZEB certification, but it is limited to only two cases. Full article

The energy industry has been trying to reduce the use of fossil fuels that emit carbon and to proliferate renewable energy as a way to respond to climate change. The attempts to reduce carbon emissions resulting from the process of generating the electric and thermal energy needed by a building were bolstered with the introduction of the concept of nZEB (nearly zero-energy building). In line with such initiatives, the South Korean government made it mandatory for new buildings to have an nZEB certificate as a way to promote the supply of renewable energy. The criteria for Energy Independence Rate, which is one of the nZEB certification criteria in South Korea, is to maintain the share of renewable energy as at least 20% of the primary energy sources for the building. For a new building in South Korea to have an nZEB certificate, it is required to establish an energy plan that would allow the building to meet the Energy Independence requirement. This optimally reflects the cost of installation for renewable energy facilities and the cost of purchasing energy from external sources, such as the national grid or district heating companies. In South Korea, the base retail rate of energy is calculated based on the peak demand per hour over the year, rather than the contracted energy. This has produced difficulties in standardizing the process with a mathematical model; in addition, there have not been many preceding studies that could be used as a reference. In this regard, this paper analyzed a modeling strategy for developing a realistic yet optimized energy plan in consideration of the unique conditions of the retail energy rates of South Korea, and analyzed the impact of the rates based on peak demands upon the total energy plan. In this study, our research team analyzed the electric billing system, conducted a case study, and analyzed the impact of the billing system that is based on the peak demand upon the optimal cost. By utilizing the restrictions for reaching the 20% Energy Independence goal, this paper calculated the proper energy supply facility capacity for renewable energy. Then, the cases in which the maximum demand modeling was used and the cases without one were compared to confirm the cost benefits observable when the suggested model is added or implemented. Full article

This paper presents the methodology for conducting a cost-optimal energy performance calculation of a solar hot water system, used for space heating and domestic hot water needs. The calculation is based on dynamic hourly methods, according to the new Energy Performance of Buildings’ (EPB) set of standards EN 15316:2017, and a revision of the standard EN 15316-5:2017 from the year 2021, dealing with storage-tank water temperature calculations. The paper provides proposals for modifications to these newly introduced standards, in order to overcome the observed ambiguities and shortcomings. The calculation of annual energy performance of a building was performed on an hourly basis over a year for the reference of an nZEB multi-apartment building, for a climate area of the city of Zagreb, taking into account water temperature change in the layers of the storage tank connected to solar collectors and hot water boilers. The cost-optimal solution was then determined by varying individual parameters of the building technical system. The influence of these parameters on the energy efficiency of the building was analyzed in detail. Furthermore, the results were compared against those obtained by the Croatian calculation algorithm based on the previous set of EPB standards, EN 15316:2008, currently used EU-wide for the energy performance certification of buildings. The results indicated that the calculation methods of the present algorithm underestimated the consumption of building primary energy by 12%. The energy delivered by solar collectors was underestimated by 18%. Full article

There is an increasing interest in new renewable energy sources for achieving net zero emissions. Consequently, the construction industry has mandated zero-energy building certification (ZEB), through the usage of new renewable energy. However, because of the variations in the energy self-sufficiency rate (ESR) among the new renewable energy types, incorrect ESR prediction at the design stage may lead to problems. Hence, in this study, the ESR and construction cost are analyzed for each new renewable energy capacity to predict the ESR of photovoltaic (PV), building integrated photovoltaic (BIPV), geothermal, and fuel cell systems. Passive and active technology elements of the ZEB cases in Korea are analyzed, and by establishing a standard model with the average value of each case, the ESR is calculated for each new renewable energy capacity, and the calculation formulas are derived. The results indicate that for the PV and BIPV systems, the rate of ESR increases with the capacity (kWp) and is constant at 0.54% and 0.34%, respectively. However, for the geothermal system and fuel cells, the average ESR is 0.016% and 1.46%, respectively, but as the rate of ESR increase with the capacity (kW) gradually decreases, the calculation formulas are derived with a log graph. Full article

The building sector has the responsibility of being a generator of high carbon emissions, due to inefficient energy consumption in the last decades. For the European Union (EU) and the building sector, this pollution has generated a great impact and concern, establishing objectives in sustainability and energy efficiency in the short term. The EU, committed to energy sustainability, has established several guidelines, aiming at reducing carbon emissions. For this reason, European directives have been published to increase energy efficiency and sustainability in buildings, with EPBD 2018/844/EU being the most up-to-date regulation. This directive mainly focuses on reducing carbon emissions and increasing the efficiency of energy systems in buildings, but it also refers to the importance of establishing indoor air quality indices and smart management of ventilation systems. Before this directive was published, many of the implemented ventilation strategies did not consider the indoor air quality (IAQ) in their scope of established comfort parameters. Therefore, this study analyses the performance of the ventilation system, controlled smartly to cover the demand and the established IAQ rates via CO₂ ppm, through renewable geothermal energy systems. This study has been carried out at the LUCIA building, a near Zero Energy Building (nZEB), which belongs to the University of Valladolid, Spain. This building stands out for being one of the most sustainable buildings in the world, according to LEED certification, ranking as the most sustainable building in the northern hemisphere. This building to study is equipped with cutting-edge energy systems, with zero carbon emissions. Several parameters have been analysed (air speed, enthalpy, air flow, temperature, humidity, kWh, climate data, etc.) enabling an energy optimisation of the combined systems. All the monitoring data obtained by the smart management have been analysed, providing favourable outcomes, due to the establishment of IAQ levels, according to the EPBD 2018/844/EU. After this study, the smart management of ventilation combined with removable geothermal energy can be exported as a strategy to reach the established IAQ levels through zero carbon systems. Full article

This study presents a methodology and process to establish a mandatory policy of zero-energy buildings (ZEBs) in Korea. To determine the mandatory level to acquire the rating of a ZEB in Korea, this study was conducted under the assumption that the criteria of ZEB was a top 5% building considering the building’s energy-efficiency rating, which was certified through a quantitative building energy analysis. A self-sufficiency rate was also proposed to strengthen the passive standard of the buildings as well as to encourage new and renewable energy production. Accordingly, zero-energy buildings (ZEBs) in Korea are defined as having 60 kWh/(m²·yr) of non-renewable primary energy (NRPE) consumption in residential buildings and 80 kWh/(m²·yr) in non-residential buildings, and the self-reliance rate should be more than 20% of the renewable energy consumption as compared to the total energy consumption of the buildings. In addition, the mandatory installation of building energy management systems (BEMS) was promoted to investigate the energy behavior in buildings to be certified as zero-energy in the future. This study also investigated the number of ZEB certificates during the demonstration period from 2017 to 2019 to analyze the energy demand, non-renewable primary energy, renewable primary energy, and self-sufficiency rate as compared to those under the previous standards. For ZEB Grade 1 as compared to the existing building energy-efficiency rating, the sum of the NRPE decreased more than 50%, and renewable energy consumption increased more than four times. Full article

The planning process of nearly Zero Energy Buildings (nZEB), as defined in Energy Performance of Buildings Directive (EPBD), requires that designers check their solutions at all stages of planning. In the initial design phase, methods and tools for which only basic design knowledge of the modelling of energy efficiency indicators is required are often sufficient. With the introduction of fast modelling techniques, designers’ work can be simplified. A method and software for the fast modelling of nZEB energy efficiency indicators of buildings constructed with advanced multi-layer glass and building integrated photovoltaics facade (BIPV) structures are presented. The computer tool for fast modelling combines (i) upgraded national certificated software for energy performance of buildings (EPB) evaluation, which is used for performing auto-repeating numerical calculations based on the design of experiments (DOE) and (ii) software for the determination of multiple linear regression models and the presentation of results. The case studies made for different buildings and climate conditions show the variety of options offered by the developed fast modelling approach. It can be seen that buildings with a large proportion of advanced glassed facade and even all-glass buildings can fulfil nZEB requirements via the on-site production of electricity with BIPV facade structures. Full article

This paper develops an energy analysis for an existing near Zero Energy (nZEB) and Zero Carbon Emissions building called LUCIA, located at the university campus in Valladolid (Spain). It is designed to supply electricity, cooling and heating needs through solar energy (Photovoltaic Systems, PV), biomass and an Earth–Air Heat Exchanger (EAHE), besides a Combined Heat Power (CHP). It is currently among the top three buildings with the highest LEED certification in the World. The building model is simulated with DesignBuilder version 5. The results of the energy analysis illustrate the heating, cooling and lighting consumptions expected, besides other demands and energy uses. From this data, we carried out an energy balance of the nZEB, which will help to plan preventive actions when compared to the actual energy consumptions, improving the management and control of both the building and its systems. The primary energy indicator obtained is 67 kWh/m² a year, and 121 kWh/m² a year for renewable energy generation, with respect to 55 kWh/m² and 45 kWh/m² set as reference in Europe. The Renewable Energy Ratio (RER) is 0.66. These indicators become a useful tool for the energy analysis of the nZEB according to the requirements in the European regulations and for its comparison with further nZEB. Full article

Successful design and construction processes aiming towards nearly zero energy building (nZEB) standards are a challenge for the whole construction industry in Europe. Realizing nZEB buildings requires innovative design processes, and technologies based on an integrated design approach facilitated by multidisciplinary work teams. The collaboration between architects, engineers, technical experts and building managers, is essential. Therefore, it is necessary to identify the specific involvement of each profession in order to develop mutual understanding of each others’ disciplines. Additionally, it is vital to provide professionals with the skills needed to achieve optimal nZEB construction and retrofitting in terms of quality, energy efficiency and cost effectiveness. However, this approach is not yet common, as the building sector is still very fragmented. The EU-funded H2020 project PROF/TRAC aims to tackle this issue by developing an Open Training Platform and a methodology for fast and valid co-creation of interdisciplinary qualification schemes for task-based Continuous Professional Development (CPD) for all professions involved. A common methodology for the mapping of skills and qualifications in the form of an Excel tool was developed as a basis, together with a guidance document. This paper presents the skill-mapping methodology, the use of its results to develop national roadmaps, and the BUILD UP Skills advisor app. Full article

The topic of nearly zero-energy buildings (n-ZEB), introduced by the Directive 2010/31/EU will direct the building market toward ever greater energy efficiency of new buildings. In some contexts, however, the building market for high-efficiency buildings has evolved, in recent years, on the basis of national and regional laws that have contributed to the acceleration of the process. This paper analyses the case study of the Lombardy Region (Italy), which transposed and assimilated the Directive 91/2002 (Energy Performance Building Directive), as of 2006, with regional legislation for energy efficiency of buildings. Within a few years the market for high energy-performance of buildings in the Lombardy Region had grown substantially: to date nearly 7500 energy performance certificates for buildings of Class A and Class A+ have been issued. The paper therefore analyses a success story in what is a field of great current interest, namely n-ZEB buildings. In the first part of the work, the evolution in terms of energy efficiency of the housing market in the Lombardy Region has been analyzed, with particular reference to the high energy-performance of buildings. The second part focuses on a sample of 20 n-ZEB buildings in order to highlight the design choices applied to them. Full article