scholarly journals Redefining cost-optimal nZEB levels for new residential buildings

2019 ◽  
Vol 111 ◽  
pp. 03035 ◽  
Author(s):  
Raimo Simson ◽  
Endrik Arumägi ◽  
Kalle Kuusk ◽  
Jarek Kurnitski
Keyword(s):  
Energy Use ◽  
Net Present Value ◽  
Residential Buildings ◽  
Energy Performance ◽  
Optimal Level ◽  
Building Envelope ◽  
Simulation Software ◽  
The European Union ◽  
Apartment Building ◽  
Detached House

In the member states of the European Union (EU), nearly-Zero Energy Buildings (nZEB) are becoming mandatory building practice in 2021. It is stated, that nZEB should be cost-optimal and the energy performance levels should be re-defined after every five years. We conducted cost-optimality analyses for two detached houses, one terraced house and one apartment building in Estonia. The analysis consisted on actual construction cost data collection based on bids of variable solutions for building envelope, air tightness, windows, heat supply systems and local renewable energy production options. For energy performance analysis we used dynamic simulation software IDA-ICE. To assess cost-effectiveness, we used Net Present Value (NPV) calculations with the assessment period of 30 years. The results for cost-optimal energy performance level for detached house with heated space of ~100 m2 was 79 kWh/(m2 a), for the larger house (~200 m2) 87 kWh/(m2 a), for terraced house with heated space of ~600 m2 71 kWh/(m2 a) and for the apartment building 103 kWh/(m2 a) of primary energy including all energy use with domestic appliances. Thus, the decrease in cost-optimal level in a five-year period was ~60% for the detached house and ~40% for the apartment building, corresponding to a shift in two EPC classes.

scholarly journals Modeling of Energy Efficiency for Residential Buildings Using Artificial Neuronal Networks

2018 ◽  
Vol 2018 ◽  
pp. 1-10 ◽  
Author(s):  
José Antonio Álvarez ◽  
Juan Ramón Rabuñal ◽  
Dolores García-Vidaurrázaga ◽  
Alberto Alvarellos ◽  
Alejandro Pazos
Keyword(s):  
Energy Efficiency ◽  
Thermal Behavior ◽  
Residential Buildings ◽  
Energy Performance ◽  
Building Envelope ◽  
The European Union ◽  
Strategic Objective ◽  
Artificial Neuronal Networks ◽  
Ann Models ◽  
Artificial Neural Network Ann

Increasing the energy efficiency of buildings is a strategic objective in the European Union, and it is the main reason why numerous studies have been carried out to evaluate and reduce energy consumption in the residential sector. The process of evaluation and qualification of the energy efficiency in existing buildings should contain an analysis of the thermal behavior of the building envelope. To determine this thermal behavior and its representative parameters, we usually have to use destructive auscultation techniques in order to determine the composition of the different layers of the envelope. In this work, we present a nondestructive, fast, and cheap technique based on artificial neural network (ANN) models that predict the energy performance of a house, given some of its characteristics. The models were created using a dataset of buildings of different typologies and uses, located in the northern area of Spain. In this dataset, the models are able to predict the U-opaque value of a building with a correlation coefficient of 0.967 with the real U-opaque measured value for the same building.

scholarly journals Airtightness and Heat Energy Loss of Mid-Size Terraced Houses Built of Different Construction Materials

Energies ◽  
2021 ◽  
Vol 14 (19) ◽  
pp. 6367
Author(s):  
Valdas Paukštys ◽  
Gintaris Cinelis ◽  
Jūratė Mockienė ◽  
Mindaugas Daukšys
Keyword(s):  
Energy Loss ◽  
Energy Use ◽  
Construction Materials ◽  
Energy Performance ◽  
Building Envelope ◽  
Living Environment ◽  
Heat Energy ◽  
Energy Class ◽  
The European Union ◽  
Certification Procedure

The European Union has adopted legislation aimed to increase the use of renewable energy and improve the effectiveness of conventional-form energy use. Additional structure insulation helps to decrease heat energy loss. Airtightness of the building envelope (building airtightness) is an additional factor that determines comfortable and energy-saving living environment. The conformity of heat energy loss with the object’s design energy class is one of the mandatory indicators used in the obligatory building energy performance certification procedure. Optionally, the objects to be certified are the entire buildings or separate units (flats). There is an issue of concern whether a flat assessed as a separate housing unit would meet the requirements of design energy class depending on the location of the unit in the building. The study is aimed to determine the change in heat loss of end units in terraced houses (townhouses) as a result of various factors, leading to uneven airtightness of the building envelope. The non-destructive assessment of building airtightness was implemented through the combined use of methods, namely Blower Door Test (around 200 measurements) and Infrared Thermography. The hollow clay unit masonry showed ca. 7–11% less airtightness than the sand–lime block masonry structure. The end units were up to 20% less airtight compared to the inside units.

scholarly journals Top Energy Saver of the Year: Results of an Energy Saving Competition in Public Buildings

2020 ◽  
Vol 24 (3) ◽  
pp. 278-293
Author(s):  
Jan Kaselofsky ◽  
Ralf Schüle ◽  
Marika Rošā ◽  
Toms Prodaņuks ◽  
Anda Jekabsone ◽  
...  
Keyword(s):  
Energy Consumption ◽  
Energy Saving ◽  
Energy Use ◽  
Residential Buildings ◽  
Electricity Consumption ◽  
Energy Performance ◽  
Heat Consumption ◽  
The European Union ◽  
Public Building ◽  
Team Members

AbstractNon-residential buildings in the European Union consume more than one third of the building sector’s total. Many non-residential buildings are owned by municipalities. This paper reports about an energy saving competition that was carried out in 91 municipal buildings in eight EU member states in 2019. For each public building an energy team was formed. The energy teams’ activities encompassed motivating changes in the energy use behaviour of employees and small investments. Two challenges added an element of gamification to the energy saving competition. To assess the success of the energy saving competition, an energy performance baseline was calculated using energy consumption data of each public building from previous years. Energy consumption in the competition year was monitored on a monthly base. After the competition the top energy savers from each country were determined by the percentage-based reduction of energy consumption compared to the baseline. On average, the buildings had an electricity and heat consumption in 2019 that was about 8 % and 7 %, respectively, lower than the baseline. As an additional data source for the evaluation, a survey among energy team members was conducted at the beginning and after the energy competition. Support from superiors, employee interest and motivation and behaviour change as assessed by energy team members show a positive, if weak or moderate, correlation with changes in electricity consumption, but not with changes in heat consumption.

scholarly journals TESTING THE NEW 3D BAG DATASET FOR ENERGY DEMAND ESTIMATION OF RESIDENTIAL BUILDINGS

2021 ◽  
Vol XLVI-4/W1-2021 ◽  
pp. 69-76
Author(s):  
C. León-Sánchez ◽  
D. Giannelli ◽  
G. Agugiaro ◽  
J. Stoter
Keyword(s):  
The Netherlands ◽  
Energy Demand ◽  
Residential Buildings ◽  
Energy Performance ◽  
Building Envelope ◽  
Simulation Software ◽  
Energy Simulation ◽  
Building Stock ◽  
Simulation Tools ◽  
Energy Simulations

Abstract. The 3D BAG v. 2.0 dataset has been recently released: it is a country-wide dataset containing all buildings in the Netherlands, modelled in multiple LoDs (LoD1.2, LoD1.3 and LoD2.2). In particular, the LoD2.2 allows differentiating between different thematic surfaces composing the building envelope. This paper describes the first steps to test and use the 3D BAG 2.0 to perform energy simulations and characterise the energy performance of the building stock. Two well-known energy simulation software packages have been tested: SimStadt and CitySim Pro. Particular care has been paid to generate a suitable, valid CityGML test dataset, located in the municipality of Rijssen-Holten in the central-eastern part of the Netherlands, that has been then used to test the energy simulation tools. Results from the simulation tools have been then stored into the 3D City Database, additionally extended to deal with the CityGML Energy ADE. The whole workflow has been checked in order to guarantee a lossless dataflow.The paper reports on the proposed workflow, the issues encountered, some solutions implemented, and what the next steps will be.

scholarly journals Application of hourly dynamic method for nZEB buildings in Italian context: analysis and comparisons in national calculation procedure framework

2021 ◽  
Vol 312 ◽  
pp. 02006
Author(s):  
Domenico Palladino ◽  
Domenico Iatauro ◽  
Paolo Signoretti
Keyword(s):  
Energy Use ◽  
Residential Buildings ◽  
Energy Performance ◽  
Building Envelope ◽  
Calculation Procedure ◽  
Reference Case ◽  
Context Analysis ◽  
Minimum Requirements ◽  
Energy Simulations ◽  
Italian Context

The Energy Performance of Buildings Directive (EPBD 2018/844/EU) requires to Member States to upgrade the methodology for the energy performance assessment of buildings. The current calculation method, based on the monthly quasi steady state calculation procedure, could be replaced in the next years by an hourly dynamic calculation procedure (EN ISO 52016), in which a resistance-capacity (RC) model is implemented to consider with more accuracy the heat exchange through the building envelope. In this framework, the present work aims at analysing and comparing the energy needs of three reference case studies of nearly Zero Energy Buildings (nZEB), applying both calculation procedures in order to investigate the main difference of the two approaches. Two residential buildings and one office, compliant with Italian minimum requirements for nZEB, were defined, and several energy simulations were carried out for all different climatic zones of Italian territory. Preliminary results highlighted significant differences of energy need mainly due to different weight of heat loss and heat gains obtained with the two considered calculation methods. This paper represents a preliminary study, but further analysis are recommended in order to evaluate the overall energy use for different type and different operation profile of buildings.

Modelling energy use in residential buildings: How design decisions influence final energy performance in various Chilean climates

2018 ◽  
Vol 28 (4) ◽  
pp. 533-551 ◽  
Author(s):  
François Simon ◽  
Javier Ordoñez ◽  
Aymeric Girard ◽  
Cristobal Parrado
Keyword(s):  
Energy Consumption ◽  
Energy Use ◽  
Residential Buildings ◽  
Building Design ◽  
Energy Performance ◽  
Building Envelope ◽  
Design Decisions ◽  
Climate Conditions ◽  
Final Energy ◽  
Effective Manner

To reduce the energy consumption in buildings, there is a demand for tools that identify significant parameters of energy performance. The work presents the development and validation of a simulation model, called MEEDI, and graphical figures for the parametric sensitivity investigation of energy performance in different climates in Chile. The MEEDI is based on the ISO 13790 monthly calculation method of building energy use with two improved procedures for the calculation of the heat transfer through the floor and the solar heat gains. The graphical figures illustrate the effects of climate conditions, envelope components and window size and orientation on the energy consumption. The MEEDI program can contribute to find the best solution to increase energy efficiency in residential buildings. It can be adapted for various parameters, making it useful for future projects. The economic viability of specific measures for building envelope materials was analysed. Payback periods range from 5 to 27 years depending on the location and energy scenario. The study illustrates how building design decisions can have a significant impact on final energy performance. With simple envelope components modification, valuable energy gains and carbon emission reductions can be achieved in a cost-effective manner in Chile.

scholarly journals Cost and Energy Reduction of a New nZEB Wooden Building

Energies ◽  
2020 ◽  
Vol 13 (14) ◽  
pp. 3570
Author(s):  
Endrik Arumägi ◽  
Targo Kalamees
Keyword(s):  
Energy Efficiency ◽  
Energy Use ◽  
Net Present Value ◽  
Performance Indicator ◽  
Energy Levels ◽  
Energy Performance ◽  
Building Envelope ◽  
Zero Energy ◽  
Construction Costs ◽  
The Cost

The current study demonstrates the possibilities of reducing energy use and construction costs and provides evidence that wooden nearly-zero-energy buildings (nZEB) are technically possible at affordable construction costs by using novel design processes and procurement models that enable scalable and modular production. The energy efficiency solutions were derived by increasing/decreasing the insulation value of the building envelope in successive steps. Financial calculations were based on the investment needed to achieve the nearly-zero-energy levels. Overall, many opportunities exist to decrease the cost and energy use compared to the current (pre-nZEB) practice because the net present value can change up to 150 €/m² on the same energy performance indicator (EPI) level. The EPI in the cost-even range was reached by combining a ground-source heat pump (between 115 and 128 kWh/(m2·a)) and efficient district heating (between 106 and 124 kWh/(m2·a)). As energy efficiency decreases, improving energy efficiency becomes more expensive by insulation measures. Throughout the EPI range the most cost efficient was investment in the improvement of the thermal transmittance of windows (3–13 €/(kWh/(m2·a))) while investments in other building envelope parts were less effective (4–80 €/(kWh/(m2·a))). If these were possible to install, photovoltaic (PV) panels installed to the roof would be the cheapest solution to improve the energy performance. Integrated project delivery procurement (design and construction together) and the use of prefabricated wooden structures reduced the constructing cost by half (from ~2700 €/net m2 to 1390 €/net m2) and helped to keep the budget within limits.

scholarly journals Evaluation of Urban-Scale Building Energy-Use Models and Tools—Application for the City of Fribourg, Switzerland

2021 ◽  
Vol 13 (4) ◽  
pp. 1595
Author(s):  
Valeria Todeschi ◽  
Roberto Boghetti ◽  
Jérôme H. Kämpf ◽  
Guglielmina Mutani
Keyword(s):  
Machine Learning ◽  
Energy Use ◽  
Residential Buildings ◽  
Building Energy ◽  
Energy Performance ◽  
Space Heating ◽  
Engineering Model ◽  
Building Energy Use ◽  
The Impact ◽  
The City

Building energy-use models and tools can simulate and represent the distribution of energy consumption of buildings located in an urban area. The aim of these models is to simulate the energy performance of buildings at multiple temporal and spatial scales, taking into account both the building shape and the surrounding urban context. This paper investigates existing models by simulating the hourly space heating consumption of residential buildings in an urban environment. Existing bottom-up urban-energy models were applied to the city of Fribourg in order to evaluate the accuracy and flexibility of energy simulations. Two common energy-use models—a machine learning model and a GIS-based engineering model—were compared and evaluated against anonymized monitoring data. The study shows that the simulations were quite precise with an annual mean absolute percentage error of 12.8 and 19.3% for the machine learning and the GIS-based engineering model, respectively, on residential buildings built in different periods of construction. Moreover, a sensitivity analysis using the Morris method was carried out on the GIS-based engineering model in order to assess the impact of input variables on space heating consumption and to identify possible optimization opportunities of the existing model.

PERFORMANCE INDICATORS FOR ENERGY EFFICIENCY RETROFITTING IN MULTIFAMILY RESIDENTIAL BUILDINGS

2019 ◽  
Vol 14 (2) ◽  
pp. 109-136
Author(s):  
Chaitali Basu ◽  
Virendra Kumar Paul ◽  
M.G. Matt Syal
Keyword(s):  
Energy Efficiency ◽  
Performance Assessment ◽  
Performance Indicators ◽  
Residential Buildings ◽  
Building Energy ◽  
Energy Performance ◽  
Building Envelope ◽  
Assessment Process ◽  
Second Phase ◽  
A Priority

The energy performance of an existing building is the amount of energy consumed to meet various needs associated with the standardized use of a building and is reflected in one or more indicators known as Building Energy Performance Indicators (EnPIs). These indicators are distributed amongst six main factors influencing energy consumption: climate, building envelope, building services and energy systems, building operation and maintenance, occupants' activities and behaviour, and indoor environmental quality. Any improvement made to either the existing structure or the physical and operational upgrade of a building system that enhances energy performance is considered an energy efficiency retrofit. The main goal of this research is to support the implementation of multifamily residential building energy retrofits through expert knowledge consensus on EnPIs for energy efficiency retrofit planning. The research methodology consists of a comprehensive literature review which has identified 35 EnPIs for assessing performance of existing residential buildings, followed by a ranking questionnaire survey of experts in the built-environment to arrive at a priority listing of indicators based on mean rank. This was followed by concordance analysis and measure of standard deviation. A total of 280 experts were contacted globally for the survey, and 106 completed responses were received resulting in a 37.85% response rate. The respondents were divided into two groups for analysis: academician/researchers and industry practitioners. The primary outcome of the research is a priority listing of EnPIs based on the quantitative data from the knowledge-base of experts from these two groups. It is the outcome of their perceptions of retrofitting factors and corresponding indicators. A retrofit strategy consists of five phases for retrofitting planning in which the second phase comprises an energy audit and performance assessment and diagnostics. This research substantiates the performance assessment process through the identification of EnPIs.

scholarly journals A Sustainable Solution for Energy Efficiency in Italian Climatic Contexts

Energies ◽  
2020 ◽  
Vol 13 (11) ◽  
pp. 2817
Author(s):  
Valeria Annibaldi ◽  
Federica Cucchiella ◽  
Marianna Rotilio
Keyword(s):  
Energy Efficiency ◽  
Life Cycle Cost ◽  
Energy Performance ◽  
Building Envelope ◽  
Reference Scenario ◽  
Life Cycle Cost Analysis ◽  
The European Union ◽  
Optimal Thickness ◽  
Hemp Fiber ◽  
Sustainable Solutions

In the European Union, about 40% of energy consumption and 36% of CO2 emissions come from buildings; therefore, the improvement of their energy performance is a strongly focused issue. In particular, the energy efficiency of the building envelope is a very important element to pay attention to. Many studies have been conducted on this field of research, and the study illustrated in this paper also belongs to this topic. In particular, this article presents a multidisciplinary method to find sustainable solutions for energy efficiency in Italian climatic contexts using the Life Cycle Cost Analysis approach. In detail, this paper defines the reference scenario and then deepens the methodology used to determine the economically optimal thickness of a specific insulating material—hemp fiber—applied to a specific type of wall—uninsulated cavity walls made of hollow bricks, which are very widespread in Italy. The analysis is developed in relation to three different regions—Piedmont, Abruzzo, and Campania. The results show that the economically optimal thickness is different for each region analyzed and demonstrates how energy efficiency strategies must be carefully weighed according to the specific conditions of the site.

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