Investigation of applicability of net zero energy buildings under the climate conditions of Türkiye

Numerous studies are being carried out in the literature to reduce the energy consumption of buildings under the concept of zero energy buildings. However, it appears that there is no generally accepted definition of Net Zero Energy Building (NZEB) and no specific design standard has been established to achieve NZEB. This study proposes a complete design methodology from preliminary stage up until usage of building to achieve NZEB. In the proposed methodology, unlike the other methods, design process has been split into two stages. Prior to reaching zero energy balance by renewables, Pareto front solutions related to building envelope parameters were found at the first stage. Subsequently, renewable energy systems, including PV array and wind turbines, were integrated into building energy model and pareto optimal solutions have been obtained for NZEB. NSGA-II genetic optimization algorithm has been implemented with developed code, to couple optimization algorithm and energy analysis software (Energyplus), in Matlab environment. Outcomes of the study showed that NZEB designs that have excess energy of up to 23 kWh/m2, 9 kWh/m2 and 3 kWh/m2 was achieved for first, second and third climate regions of Türkiye, respectively. For the fourth climate region, where the heating load is the most dominant, although the energy use intensity has decreased to 10.4 kWh/m2, the roof area is not still sufficient to compensate for all the energy consumed. It was also revealed that the share of initial investment cost of renewable energy is 19%, among the overall initial cost and payback period of this investment targeting NZEB is around 3.5 years if the proposed methodology is followed.