Search

Buildings Energy Certification System (SCE) was implemented in Portugal through the publication of the Decree-Law 78/2006 and due to the adjustment of national legislation imposed by EPBD 2002. Thus, since January 1, 2009 all residential and service buildings, new, refurbished or existing must have an Energy Certificate in any construction, purchase or lease process. During the last 10 years, and not only due to EPBD recast that occur in 2010, the legislation has undergone dozens of changes, interpretations and corrections being important to realize their impact on the main indicators of buildings energy efficiency. Through the application of the three calculation methodologies, adopted by SCE in these 10 years, to a single-family house that was certified in 2009, it was possible to verify that the main indicators of energy efficiency have changed drastically. Keywords: Energy efficiency, Energy certification, Buildings regulation, EPBD, SCE

This study explored which envelope solutions in retail buildings led to cost-optimal levels considering the Energy Performance of Building Directive and Portuguese regulation. For such, energy simulations were run in BIM software based on the analysis of a case study in Portugal. Typical alternative solutions were tested against the original case study, and solutions with considerably lower U-value considering the code for commercial buildings (0,7 W/m2.°K for walls and 0,5 W/m2.°K for roofs). To assess the cost-effectiveness of alternative envelope solutions, the Payback Period, the Net Present Value and the Internal Rate of Return at 15 years and 50 years were assessed. Results indicate that solutions with lower U-values are related to 2–5% savings in energy consumption and can be cost-effective at 15 and 50 years, namely vacuum insulation panels of 2.5 cm and sandwich panels of 8–12 cm. This leads to the conclusion that lowering present code U-values can be cost-effective, but it will result in additional initial costs., This work was supported by FCT - Fundação para a Ciência e Tecnologia [grant number PD/BD/127852/2016] under the Doctoral Program EcoCoRe - Eco-Construction and Rehabilitation. Support from CERIS and Instituto Superior Técnico is also acknowledged.

"Efficient Solutions and Cost-Optimal Analysis for Existing School Buildings" (Paolo Maria Congedo, Delia D'Agostino, Cristina Baglivo, Giuliano Tornese, Ilaria Zacà) [1] is the paper that refers to this article. It reports the data related to the establishment of several variants of energy efficient retrofit measures selected for two existing school buildings located in the Mediterranean area. In compliance with the cost-optimal analysis described in the Energy Performance of Buildings Directive and its guidelines (EU, Directive, EU 244,) [2], [3], these data are useful for the integration of renewable energy sources and high performance technical systems for school renovation. The data of cost-efficient high performance solutions are provided in tables that are explained within the following sections. The data focus on the describe school refurbishment sector to which European policies and investments are directed. A methodological approach already used in previous studies about new buildings is followed (Baglivo Cristina, Congedo Paolo Maria, D׳Agostino Delia, Zacà Ilaria, 2015; IlariaZacà, Delia D'Agostino, Paolo Maria Congedo, Cristina Baglivo; Baglivo Cristina, Congedo Paolo Maria, D'Agostino Delia, Zacà Ilaria, 2015; Ilaria Zacà, Delia D'Agostino, Paolo Maria Congedo, Cristina Baglivo, 2015; Paolo Maria Congedo, Cristina Baglivo, IlariaZacà, Delia D'Agostino,2015) [4], [5], [6], [7], [8]. The files give the cost-optimal solutions for a kindergarten (REF1) and a nursery (REF2) school located in Sanarica and Squinzano (province of Lecce Southern Italy). The two reference buildings differ for construction period, materials and systems. The eleven tables provided contain data about the localization of the buildings, geometrical features and thermal properties of the envelope, as well as the energy efficiency measures related to walls, windows, heating, cooling, dhw and renewables. Output values of energy consumption, gas emission and costs are given for a financial and a macro-economic analysis. This data article provides 288 and 96 combinations for REF1 and REF2, respectively. The output values are obtained using the software ProCasaClima 2015v.2.0.

This data article contains eleven tables supporting the research article entitled: Cost-Optimal Design For Nearly Zero Energy Office Buildings Located In Warm Climates [1].The data explain the procedure of minimum energy performance requirements presented by the European Directive (EPBD) [2] to establish several variants of energy efficiency measures with the integration of renewable energy sources in order to reach nZEBs (nearly zero energy buildings) by 2020.This files include the application of comparative methodological framework and give the cost-optimal solutions for non-residential building located in Southern Italy. The data describe office sector in which direct the current European policies and investments [3,4].In particular, the localization of the building, geometrical features, thermal properties of the envelope and technical systems for HVAC are reported in the first sections. Energy efficiency measures related to orientation, walls, windows, heating, cooling, dhw and RES are given in the second part of the group; this data article provides 256 combinations for a financial and macroeconomic analysis.

The Energy Performance Certificate (EPC) has an especial feature for existing buildings, a Recommendation List of Measures (RLM) designed to improve the energy performance of these buildings. This feature has not been properly studied by researchers or policymakers, in spite of being one of the main tools that can encourage building owners to perform renovation activities. Considering the scarce research focusing on the recommendations list of measures, more information is needed in order to identify weaknesses, barriers and improvements of this tool. This is especially important since the European commitment to reduce their emissions in 2020 are far from reaching the proposed goals, mainly becouse of the low renovation rate. This critical review is based on the current literature mainly from reports delivered by the Commission and academic research. The study focuses on the requirement set by the directive, its current performance, barriers and improvements that can be made to take this tool to a level that can be effectively used by policymakers, certifiers and owners. The upgrade of the recommendation list of measure should strengthen their calculation methods and procedure from both local authorities and the Commission. This should be in line with the certifiers’ needs in order to do relevant work, including proper training, mandatory field inspections and tools. Lastly, financial policies and information should be implemented to accompany the certificate, ensuring that building owners interested in renovation have assistance and financial facilities or easy access to relevant information on this matter. The main conclusion of this study reveals that the regulatory framework could use some strictness in order to avoid ‘just enough’ implementations. Ambiguous definitions and too flexible obligations should be revised, especially cost-effectiveness and training for the certifiers. Attention on how to deliver the information to building owners should be increased, allowing them to understand the results, its implications and how to concretize renovation work through financial mechanisms, thus increasing the reliability of the EPC and the RLM.

Energy efficiency in buildings is a crucial topic to reduce worldwide energy consumption and fight climate changes. A key aspect is the assessment of the heat transfer through the opaque elements of the building envelope. One way to do it is modeling the element as a resistors and capacitors network (RC), using the thermal-electrical analogy. In the hourly dynamic method introduced by the recently published standard EN ISO 52016-1:2017, each opaque element is modelled with an RC-network. Italy has implemented in the National Annex A of the Standard an alternative methodology for the definition of the number of nodes and position, based on the detailed layers’ characteristics. In this work, the two methods are described and compared with the exact analytical solution for three cases under sinusoidal boundary conditions. In all the test cases, the results obtained applying the Italian Annex provide better results, with a reduction of the error on the internal flux amplitude between 14% and 67%. In addition, it has been verified that the Italian model is actually well-tuned. Indeed, the amplitude of the external flux is overestimated on average of only 3%, and the phase differences are limited (maximum ±1 h). Lastly, also the effect of the change of the number of nodes, and to move the nodes from the layers’ mid-point to the interface, have been analysed, but none of these strategies were demonstrated able to increase significantly the model accuracy, which can be obtained only reducing the calculation timestep.

Directive 2002/91/EC of the European Parliament and Council on the Energy Performance of Buildings has led to major developments in energy policies followed by the EU Member States. The national energy performance targets for the built environment are mostly rooted in the Building Regulations that are shaped by this Directive. Article 3 of this Directive requires a methodology to calculate energy performance of buildings under standardised operating conditions. Overwhelming evidence suggests that actual energy performance is often significantly higher than this standardised and theoretical performance. The risk is national energy saving targets may not be achieved in practice. The UK evidence for the education and office sectors is presented in this paper. A measurement and verification plan is proposed to compare actual energy performance of a building with its theoretical performance using calibrated thermal modelling. Consequently, the intended vs. actual energy performance can be established under identical operating conditions. This can help identify the shortcomings of construction process and building procurement. Once energy performance gap is determined with reasonable accuracy and root causes identified, effective measures could be adopted to remedy or offset this gap.

Data are related to the numerical simulation performed in the study entitled “CFD modeling to evaluate the thermal performances of window frames in accordance with the ISO 10077” (Malvoni et al., 2016) [1].The paper focuses on the results from a two-dimensional numerical analysis for ten frame sections suggested by the ISO 10077-2 and performed using GAMBIT 2.2 and ANSYS FLUENT 14.5 CFD code.The dataset specifically includes information about the CFD setup and boundary conditions considered as the input values of the simulations.The trend of the isotherms points out the different impacts on the thermal behaviour of all sections with air solid material or ideal gas into the cavities. Keywords: CFD, Thermal break, Window, Frame, 10077, EPBD

The EU energy policy sets an energy efficiency increase target of 20%, which is being implemented in the legislation of Member States in different ways. The greatest potential for energy savings of nearly 40% lies in buildings. The Spanish building sector has developed several instruments for significant savings. The purpose of this study is to analyze those instruments and their effectiveness and efficiency. In Spain, energy efficiency in buildings is improving more slowly than in other EU Member States, but the new regulation will open a new opportunity to recover the lost years. However, the current economic crisis, demotivation of its citizens, decentralization of power in energy matters and the large stock of housing for sale, impede achievement of energy efficiency goals