This study evaluates strategies to achieve carbon neutrality in office buildings in Hong Kong and examines whether current energy efficiency standards and guidelines foster a 40% reduction of energy use intensity (EUI) by 2025. EnergyPlus was used to simulate energy efficient tactics for the envelope and systems in a reference office building under climate scenarios predicted for 2050 and 2080. Current standards help reduce the EUI by up to 19.23% in 2020 but the reduction shrinks to 10.47% in 2050 and 3.36% in 2080. Using daylight dimming control, extensive photovoltaic panels and advanced heating, ventilating and air-conditioning technologies will reduce carbon emissions by 31.99% in 2050 and 28.05% in 2080. Feasible carbon neutral policies proposed involve lowering carbon emission factors at the supply side, widening renewable energy applications to directly cut carbon emissions, and upgrading energy efficiency standards for building systems.