International Conference on Advances in Civil, Structural and Environmental Engineering - ACSEE 2013
Author(s) : JIRI HEJHALEK, MONIKA CULAKOVA, SILVIA VILCEKOVA
The building sector is known to be dominant consumer of energy resources, contributor to greenhouse gas emissions and other environmental impacts. Over the last decade, the development towards sustainability hasbecome important issue in building design decisions. Life cycle assessment (LCA) belongs to broadly used methodology which helps to make decisions in sustainable building design. In this paper, environmental building material performance of wall assemblies for exterior wall is evaluated through LCA (construction phase). The relative contribution of embodied impacts of building materials has been recognized as being significant, especially for high energy effective residential buildings. The exterior walls of houses were by far the most significant contribution of embodied impacts associated with the construction phase. The case study assesses environmental indicators such as embodied energy from non-renewable resources, embodied emissions of CO2-eq. and SO2-eq. (within boundary from cradle to gate) of wall assemblies of newly designed nearly zero houses. The material compositions of walls are also calculated in terms of selected thermal-physical aspects in order to assure reduction of future energy consumption during operation. All results are compared by using multi-dimensional evaluation approach through four mathematical methods. The multi-criteria decision analysis (MCDA) demonstrates that this way of material optimization of exterior walls it is possible to ensure markedly reduction of energy consumption and carbon footprint of building. The second variant from massive wood panel and other materials on wood base is able to absorb more than 300 kg of equivalent CO2 emissions per square meter of structure and to improve overall energy balance of structure in despite of this wall achieves the highest value of embodied energy in comparison with other variants.