ENVIRONMENTAL FRIENDLY BUILDING CONSTRUCTION, EFBUCO

The International Energy Agency (IEA) statistics estimate in a 2004 report that globally the building sector is responsible for 42% electricity consumption, more than any other sector [1]. Since 1992 the World Energy Council (WEC) and ADEME (Agency for Environment and Energy Efficiency, France) are collaborating on a joint project “Energy Efficiency Policies and Indicators” to develop strategies to reduce energy consumption. Since 2008, more than 70 countries adapted policies to improve energy efficiency of buildings.

European countries like the UK, Germany, Spain [2][3] and other indicate in their annual reports of recent years that the housing sector is consuming a quarter of the energy consumed by the whole country. This keeps the housing sector the main consumer of energy after transportation although notable measures are taken, which refer to the operation time of the life cycle of buildings.

The energy consumption (EC) of this sector is divided in embodied energy (EE), which refers to the extraction of raw materials, transportation and fabrication of construction materials, as well as the technology used for the construction of the building, and the EC for operation of the building and demolition or recycling that is considered in Life Cycle Assessments (LCA) [4][5][6][7][8][9]. The latter is already well analyzed and solutions how to reduce EC are practiced. These developments are monitored in 28 European countries by the Odyssee-Mure project supported and funded by the EU Commission and most of the Energy Agencies of member countries. They relate an improvement of energy efficiency in the housing sector of 12% from the years 2000 to 2010 [10]. Governments support these practices, because the demands for energy services are growing and costs of efficiency are lower than supply and have additionally favorable secondary economical effects.

Despite all of these efforts, the EE is not well analyzed and is not known to the public. In a previous research we could prove that EE can account for 31% of the whole EC, which was published in 2017 [11]. Data on individual construction materials concerning their gas emissions and embodied energies are available but the data is of little use in the context of architectural design. Inevitably, the question “Which construction process and material is more environmental friendly for my project?” remains unanswered. The three aspects of sustainable construction, gas emissions, embodied energy and economy; depend very much on the quantity of material to use. The quantities differ between construction systems to use, which are also in function of the architectural design. The right decision to cover this issue must be taken in the initial phase of a project. Researches on this field are mainly not covering this subject and are evaluating materials in existing buildings or presenting life cycle assessments, which are not enough as new projects are different in architecture. These researches are conditioned on a specific localization and architecture; consequently the results may guide but are not conclusive. As the EE is in function of quantity of construction materials, the challenge is to inform the consumer at the initial phase of design and not at the end as it happens with the costs.  For example concrete and ceramic brick have very similar EE benchmarks, 1,02 MJ/kg for ceramic brick and 1,01 for concrete, but depending on the architectural design and construction technology to be used the outcome will definitely not be similar. So far no methodology is available to provide the EE and costs upfront in combination with the architectural design and the construction technology to be applied. The cost factor makes the results even more attractive to project owners and it underlines also the novelty of this research. This kind of information is on scientific basis not available and can contribute to the mentioned policies supported by the EU Commission. The majority of the building stock of a country consists of small buildings, which can be built using a variety of technologies. The research aims to address these projects. In a first phase through comparison of construction technologies a digital manual of easy consultation and guidance can be provided. In the second phase a developed virtual model with variable common span length for habitat will be made available as software, which enables to compute benchmarks and costs based on functional units. Both, digital guide and software, target to help the architect, engineer and other experts to make, in the initial phase of design, the right choice of construction technology to build economical and ecological. In a third phase the prefabrication of construction solutions will be considered to enhance the effectiveness of the results from the first phase. Moreover, it will be of general interest to transmit these solutions to the rehabilitation sector.  The research is in accordance with the goals of the European Union H2020 and the 2030 Agenda concerning the following targets:

-Primary energy savings;

-Measurable cost reduction compared with a typical renovation;

-Reduction of time needed on site for renovation works by 20% compared to current national standard practice;

-Demonstration of the effectiveness and replicability of the proposed solutions to lead to an increased rate of renovation for defined building typologies in several districts/cities/regions;

-Reduction of the greenhouse gases emissions.