This project optimizes the design with detailed energy simulation and recommends ten energy-efficient solutions with sensitivity analyses for each one. It also includes a cumulative analysis of energy savings for ten solutions. The results show that when implementing all ten building solutions, the energy consumption coefficient decreases from 136kWh/m²/year to 66kWh/m²/year. The solutions include natural ventilation, the setting of 27^oC temperature, lighting controls, CO2 sensors, SHGC 0.26 glass, a 50% WWR window open ratio, the installation of a thermal recovery device, autoclaved light bricks, double-glazed SHGC 0.44, a sunshade installed 3x20cm wide, and a 50% opening of the rear sliding door.

There is an opportunity for the project to save 3.2 billion VND in investment with a reduction in the air-conditioning system’s capacity, which saves 4.7 billion VND, by installing a heat recovery system, worth 1.3 billion VND, to improve the energy efficiency of the building, and by installing 200m² of energy-efficient glazing. The work has been carefully analyzed to balance the investment costs. The optimization of the design through energy simulation helps reduce the cost of the air conditioning system, and the structural system for the body and foundation, which entails increased materials cost and thermal recovery device cost. Consequently, the building will have better thermal and lighting comfort and lower annual energy consumption costs.