2.1.1. The impact on European buildings

minimum energy efficiency requirements. Upon determining whether a macroeconomic or financial method can be used to develop nationwide reference average values of the measured cost-optimal energy levels for all reference buildings, average values of the measured cost-optimal energy levels for all reference buildings will be defined to allow for comparison with average values of existing energy performance criteria for similar reference buildings (Commission Delegated Regulation (EU) No 244/2012 of 16 January 2012 supplementing Directive 2010/31/EU of the European Parliament and of the Council). This allows for the estimation of the energy performance gap between current energy performance requirements and calculated cost-optimal levels.

2.1.1. The impact on European buildings Germany The first edition of the national typology of residential construction was produced in 1990 on the basis of energy audit reports and was used to estimate the energy efficiency potential of buildings during scenario analysis. The construction typology was revised on a regular basis to reflect new advances (e.g., new energy conservation rules) and was initially used as a model for the building stock in various studies (IWU, 2003). The current edition includes 44 different types of residential structures that are classed according to their construction year and size. It describes the buildings' present state of repair. Building data are documented in and include the following: - Basic information about the structure (floor area, number of units, etc.), the areas of structural elements (walls, roofs, ground floors, and windows), and the U-values of structural elements. - Energy performance and saving potentials which are documented in the form of a two-page report. - In addition to the measures needed to improve EP a report of energy analysis and advice from national regulations is known - Proposals for the use of a number of funding programs and software for applications as a set of exemplary constructions. - Energy class and generating a certificate.

Greece Prior to 2008, Greece lacked comprehensive monitoring of its building stock. After the ratification of Law 3661 / 19.05.2008 on the National Adaptation of the EPBD Directive, the new Energy Performance Regulation of Buildings - KENAK (KYA 5825 / 09.04.2010), and the release of national technical guidelines (TOTEE) and tools scheduled in mid-2010 [58]. Data on Hellenic residential structures were gathered from a variety of sources (National Registration of Hellenic Statistical Services of constructions 1990-2000 and published literature). The endeavor resulted in the design of the appropriate number and size of buildings for: a. Structures (e.g., residential and non-residential buildings (offices/commercial, hospitals, hotels, and schools)) b. Date of construction (i.e., three typologies based on the year of construction: prior to 1980 (when the national regulation of thermal insulation took effect), 1980-2001 (when the code's implementation was gradually changed), and predictions to 2010) c. Four distinct climate zones (A, B, C, D - discretization based on the number of days of the heating rate in accordance with the draft National Regulation on the implementation of the EPBD). d. Similarly, a map of specific annual operational consumption of electricity and heat has been achieved for different categories. Additionally, a classification of the two types of residential buildings stated before was achievable based on their thermal properties and installed heating systems during three distinct construction periods, namely before 1980, 1980–2001, and 2002–2010.

Slovenia Several attempts have been made in the past to compile construction typologies. To begin, there was a research conducted in the mid-1990s. The study examined how much energy is consumed by structures. Then there are construction typologies for statistical analysis and another for CO2 scenarios. It later reduced to just two types of construction (single family home and apartment

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construction) and required numerous years of construction classes corresponding to various levels of energy efficiency. The present condition of the residential building was analyzed (as part of the project for Energy Conservation of Existing Residential Buildings), and the structure was separated into distinct architectural designs. Additional stock buildings for each form of construction are considered on a regular basis. Since 1991, the population census served as the foundation. Then, only structures constructed after 1980 were included in the analysis. The year 1980 relates to the national standard, which imposes tougher requirements on the thermal characteristics of building components and energy-efficient construction. 18 construction typologies were identified as in need of energy efficient rehabilitation, and each was assigned a renovation plan. The renovation plan considered mainly the winding of the construction. The variations in energy consumption between these two scenarios correlate to the energy savings calculated on a national scale.

Italy Until 2010, no formal construction typology was offered in Italy on a national scale. Italy has made scientific advances in this area in specific places. Regarding the typology of construction in Italy, the following points can be made regarding the building stock: - a high proportion of historic buildings; - a low rate of renovation; - a widespread lack of inspections for compliance with energy-related building regulations; - significant climatic differences between regions; - distinct construction traditions (heavy construction in the south, wood construction in the alpine areas); - widely dispersed U values and heating systems; - disparities in construction age and level of insulation. Several studies have been undertaken that can provide important data on the typology of buildings connected to energy valuation, based on significant national trends and data sources for the development of construction typology: a. investigations undertaken by POLITO DENER as part of a series of research initiatives aimed at characterizing and evaluating the energy performance of existing Italian buildings. b. established national research studies and standards that provide information on building construction and heat supply systems in the Italian building stock, as well as energy conservation strategies. (For example, in the 1980s, studies undertaken primarily by the National Energy Agency focused at describing the typology of construction stocks); c. national statistical data on the building stock, including detailed data from the National Institute of Statistics (ISTAT) and CRESME (Economic, Social, and Market Center Sector in the Construction Sector); d. information on construction typologies and technical systems obtained from regional construction associations; e. data sets on energy certification compiled by local energy agencies and consulting firms. f. Statistical statistics are published in the ENEA's (National Energy Agency) "Energy and Environment Report 2006" (June 2007) (ENEA, 2007) Typical exterior walls are summarized in the Italian standard UNI / TS 11300-part 1 (national annex to EN ISO 13790). Specifically, 19 typical constructions are discussed. The following parameters are shown for each of them: • layers (materials, thickness, density, and thermal conductivity); • location of construction; and • age of the structure.

Conclusions Combining seismic and energy retrofitting, can be a huge cost for the investors. Therefore political initiatives are needed to encourage this investment. A good example is Italy, where the government propose reduce taxes for those who do one or both retrofits. USA uses tax reifies for energy retrofits. However, this can be not a good solution for the low-income population that are not taxpayers. Netherlands uses loans in order to cover retrofit costs. With these initiatives, the payback period may 42

be 10 to 11 years. Italy uses seismic certificate that show that seismic performance of building. This, like the energy certificate, is used to raise the value of the property. Most of the Slovak building stock, before the 1980, a time when were no energy regulation. The new politics set the targets to 45% of reduce energy demand. The actors are the Homeowners Association, which collect a fund paid by the owners building for maintenance and repairs. For the energy retrofitted buildings is issued a certificate. In Estonia, to be within the guidelines of the European regulation, is used energy certificate. These certificates are mandatory in order to sell buy or rent a house. Also, as they serve as the Consumer Protection, there is the information about the energy performance of a building. In Bulgaria most of the buildings are from the communist era. This sector is characterized with low energy efficiency. In order to cope with the high energy consumption, Bulgarian government create the fund that could lend money for the energy retrofit and offer technical assistance. After the energy retrofit, the savings where 720 euros per house. Renovating existing structures would make a significant contribution to the betterment of numerous critical facets of our society and daily lives. Currently, the EU's very low energy rehabilitation speeds are unable to generate sufficient energy savings, which must at least double in the near future if the EU is to attain carbon neutrality by 2050. Enhancing the energy efficiency of buildings would improve citizens' living standards and benefit a diverse variety of financial sectors. Considering the interconnectedness of EU economies, closing the divide between some areas is a vital requirement for ensuring Europe's growth is harmonic, balanced, and sustainable. Significant progress has been achieved in recent years through the Energy Performance of Buildings Directive (EPBD) and the Energy Efficiency Directive (EED) (EED). Nowadays, new structures consume less than half the energy that structures constructed 30 years ago did. However, because about 80% of today's buildings will remain in operation in 2050 and 75% of this stock is inefficient in terms of energy use, the European Green Deal (EGD) anticipates implementing the 'Renovation Wave' project in this sector, as outlined in the 2020 Commission Work Programme. The EGD's objective is to turn the EU into a just and successful society with a modern, resource-efficient, and competitive economy that decouples economic growth from resource use. Why is increasing building energy efficiency a win-win situation? While repair of existing structures is not a panacea, it would significantly contribute to the improvement of a number of critical components of our society. The environment (i.e. climate change, local pollution, and resource use), the economy (i.e. sustainable growth, industry competitiveness, and job opportunities), energy infrastructure (i.e. energy security and reliance), and human wellbeing (i.e. energy poverty, health, and living conditions) are the primary concerns. By limiting global warming to far below 2°C, the Paris Agreement established a worldwide framework for avoiding severe climate change. The EU building stock is Europe's greatest single energy consumer, accounting for 40% of energy consumption and 36% of EU greenhouse gas emissions. Due to this particular weight, energy efficient buildings are critical to achieving a global environmental solution. Additionally, fine particle emissions (PM2.5 and PM10) from fuel burning for heat and transportation are concentrated primarily in cities. Construction accounts for 9% of EU GDP and almost 15 million direct and indirect jobs. Nearly the entirety of the value chain is based in Europe. Specialized construction activities, such as renovations and energy retrofits, employ nearly two-thirds of all construction workers. Energy retrofits of existing buildings contribute to energy import reductions, which increased from little more than 44% of gross available energy in 1990 to 55.1 percent in 2017. The building stock has a significant impact on gas imports, and retrofitting 2% of the EU's building stock annually (together with some electrification of heat demand) will result in a 25% reduction in estimated peak monthly gas consumption in buildings by 20401. Building renovations help citizens and businesses save money on operating costs. Vulnerable individuals in Europe are disproportionately affected by inefficiency in the built environment and growing energy costs. Over 50 million families in the EU are expected to be in energy poverty as a result of inefficient buildings and equipment, high energy costs, low household incomes, and unique household demands.

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