The Building sector is the largest consumer of energy worldwide. Net Zero Energy Residential Building (NZERB) is one of the prudent approaches to reduce pressure on primary sources of energy. The main objective of this study is to use Taguchi simulation based on orthogonal arrays approach to optimize thermal envelope of a building, SEER value of HVAC system, lighting power density, and ventilation level to reduce the Building Energy Intensity (BEI) 50% lower than the base case building according to International Energy Conservation Codes 2015. In this study whole building energy simulation was performed by Hourly Analysis Energy Program and PVWatts calculator was used to estimate the size of the PV system for balancing the energy demand of the house. The results of Taguchi simulation approach show that by decreasing the U value of wall, windows, roof, floor to 0.1, 0.8, 0.1, 0.2 W/m2. °K respectively and ventilation rate 0.15 l/s-m2, lights of 110 lm/W and SEER of the HVAC system 4 (W/W option) reduce BEI from 147.78 kWh/m2/year for base case building to 67.085 kWh/m<jats:sup>2</jats:sup>/year for optimal design case. PV system size estimation was performed with PVWatts calculator. PV Watts recommended the size of 13kW DC rating system (open rack type) of 15% efficiency for the weather of Johor Bahru to meet the annual energy demand of the proposed optimal building design.
