Green Retrofit Energy Efficiency Potential on Existing Building Envelope for Residential and Non-Residential Building

Green Retrofit Energy Efficiency Potential on Existing Building Envelope for Residential and Non-Residential Building

Robert Staiger (E3xpert, Germany)
Copyright: © 2019 |Pages: 31
DOI: 10.4018/978-1-5225-9104-7.ch010

Abstract

The chapter deals with the green energetic consideration of today's building envelopes for residential and non-residential buildings. It investigates the energetic effects the envelopes have on energy efficiency, energy consumption, material use, sustainable use of resources, lifetime considerations, economic and ecological impact. Today's it is estimated that approximately 30% of the annual primary energy demand for residential and non-residential buildings is needed. Energy resources for heat, electricity, air conditioning and cooling purposes, fossil fuels in form of gas and liquid are predominantly used.
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Green Energetic Renovation Of Building Envelopes

The chapter deals with the green energetic consideration of today's building envelopes for residential and non-residential buildings. It investigates the energetic effects the envelopes have on energy efficiency, energy consumption, material use, sustainable use of resources, lifetime considerations, economic and ecological impact.

Today's thermal energy is estimated that approximately 30-35% of the annual primary energy demand for residential and non-residential buildings are needed. As energy resources for the transformation processes in heat, electricity, air conditioning and cooling purpose, fossil fuels in form of gas and oil are in present predominantly used (BP 2018).

The burning of fossil energy sources since the industrial revolution of the 1800s, CO2 pollution is steadily increasing in our atmosphere (Rosenzweig et al., 2018). This rising Concentrations of greenhouse gases are changing our climate at an ever-faster pace (Hutter, 2018). The consequences of the worldwide use of fossil fuels have been scientifically proven and the causative agent clearly transferred (Schönwiese, 2019).

The annual amount on fossil oil per annum are more than 14.000 Mill litre of crude oil per day and 100 mill tons on coal per day (BP 2018). Generating out of these fossil energy source different energy forms mostly through thermal burning processes more than 32.000 mill tons on CO2/a are polluted in the air. CO2 is the second most important greenhouse gas that drives climate warming process. In addition to that, a further large number of health-endangering gases and dusts are emitted into the environment.

The amount of Buildings in Germany in 2018 are roughly 42 Mill. The total surface area is roughly 3.900 Mill m2 in Germany (DENA 2019). Worldwide estimation is 42.000 Mill houses and buildings. (Krieger, 2017).

The building envelope comprises all the components enclosing it to the outside, e.g. walls, windows, roofs and floors. For a sustainable construction, especially the thermal building envelope is of importance. It includes all components that separate heated rooms from outside air, from the ground and from unheated rooms. The thermal insulation of the thermal building envelope is crucial for the transmission heat demand of a building (Garzon, 2018; Swan, 2013; Wilson, 2013).

Buildings have a much longer service life compared for example to vehicles. While vehicles could theoretically be replaced by environmentally friendly new vehicles within a decade with appropriate regulations, this is not possible with buildings. And in terms of sustainability, it also makes no sense: the continued use of existing buildings, their renovation, conversion and further construction is usually connected with a significantly lower energy and resource consumption than a demolition and new construction, if the grey energy is included.

Key Terms in this Chapter

Live Cycle Assessment: A Life Cycle Assessment (LCA) is a systematic analysis of the environmental impact of products throughout their life cycle “from cradle to grave.” Life Cycle Assessment includes all environmental impacts during production, the usage phase and the disposal of the product, as well as the related upstream and downstream processes

Building Envelope: The building envelope is a closed geometric structure and the physical separation between the internal and external environment of a building. It comprises all the components of a building that close it to the outside like walls, roof, windows, and floors.

Nearly Energy Building: lowest energy building with a very high energy efficiency defined in Annex 1 EBPD. The main part of the energy should come from renewable energy sources.

Energy Performance Building Directive: Directive on the energy performance of buildings. The new regulation aims to make buildings “smarter” and more energy efficient. They enable saving greenhouse gases, financial savings and contribute to the creation of new jobs in the renovation and construction sector.

Passive Energy building: A building standard that is truly energy efficient, comfortable, economical and environmentally friendly at the same time. The passive house is not a brand name, but a construction concept that is open to all - and has proven itself in practice. The heating demand in the passive house is less than 15 kWh / (m 2 a) per heated surface.

Insulation Materials: An insulating material is a building material that is preferably used for thermal insulation. Thermal insulation materials are materials with low thermal conductivity and reduce heat or cold losses

U Value: A measure of the heat transfer is the heat transfer coefficient or U-value, its unit is given in W / (m 2 K). This value takes into account the heat transfer effects of convection and radiation. A small heat transfer coefficient leads to less heat loss in the heating time - the heat remains in the building. In summer, the small U-value also has a positive effect - the heat stays outside the building.

Energy Balance Method: Energy balance methods enable the optimization of the building under the given economic conditions. The energy flows for the building to be calculated are determined using this method. These energy flows can be determined daily, weekly, monthly and annually. Depending on the location of the building, additional meteorological data are included in the calculations

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