The Effect of Embodied Impact on the Cost-Optimal Levels of Nearly Zero Energy Buildings: A Case Study of a Residential Building in Thessaloniki, Greece

Abstract

Considering the nearly zero energy building (nZEB) and the increased measures for the improvement of the energy efficiency, the international literature indicates an extended use of specialized materials and technical installations. An increase in the embodied energy follows that use, with a final share between 74% and 100% in the total life cycle energy of residential nZEBs. The current energy efficiency legislation considers only the impact from the operational phase and ignores the embodied impact from the remaining life cycle phases of the building. Nevertheless, the delegated regulation 244 of 2012 acknowledges the incompleteness of this assessment and provides an optional consideration of the embodied ("grey") energy. The current study applies this option through the macroeconomic global cost calculations and the cost-optimal levels of nZEBs. The results indicate a limited effect of the embodied impact on the cost-optimal levels and in specific on extended calculation periods and in combination with other key parameters of the sensitivity analysis. An increase in the primary energy and a transposition to variants with lower use of materials and decreased embodied emissions follow this effect. Sensitivity analysis confirms the calculation period as a key parameter and indicates the need for further research.

Energy Analysis at a Near Zero Energy Building. A Case-Study in Spain

“…As a result, southern region of Spain arises among the few ones where heating and cooling demands of nZEB can be covered without resorting to exhaust air heat recovery. Chastas et al [17] develop an analysis of the embodied energy of a residential building in Greece with a heated area of 123.75 m 2 . Their results show that this approach of the primary energy balance can overcome the limitations of the current European Legislation in what concerns Life Cycle Analysis (LCA) and embodied energy, emissions and environmental impact.…”

Exploring the current challenges and emerging approaches in whole building life cycle assessment

“…The database are used globally to assess the environmental impacts of different products/processes that are happening in different countries, although they could easily be misused. One study indicates that the embodied CO 2 e results could be over 50% different between Ecoinvent database and ICE database for different building designs (Chastas et al 2017). Therefore, a lot of uncertainties/errors are embedded in the LCA studies.…”

Energy and Environmental Analysis of Single-Family Houses Located in Poland

“…Many studies investigated energy-efficient, passive or nearly zero-energy buildings (nZEB) and buildings using renewable energy sources [21][22][23][24][25][26][27]. Audenard et al [21] conducted an economic analysis of a passive house and compared it with a standard house.…”

“…• the window opening area will change at certain times (on weekdays: 6, 8, 15, 18, 22, on weekends: 8,11,14,17,18,22). In between the abovementioned hours, the windows will be fixed, • the windows will be assumed to be closed if there are no residents in the building, • the maximum allowable air change rate ACH max = 10 h −1 .…”