The Green Energy (GEO) Building is a pioneering office building designed to become the country's first Zero Energy Office (ZEO) building, formerly known as the Pusat Tenaga Malaysia (PTM) ZEO building, currently as GreenTech Malaysia (2021). This means that the building will consume no more electricity that what can be produced via the Building-Integrated Solar PV (BIPV) system. This highly energy efficient and innovative building was taken into use in November 2007 and initially achieved an Energy Index of 64 kWh/m2/year (without Solar PV) and 35 kWh/m2/year (with Solar PV), or 15% of the consumption of a typical office building. Recently, additional Solar PV has been added to the building, bring the Energy Index down to 15 kWh/m2/year (with Solar PV). And with the upcoming chiller replacement, it is hoped to bring the building to Zero Energy, as per the original design intent.

Every aspect of energy consumption was studied and optimised. As such, the building has a long range of energy efficiency features integrated in the architectural as well as the M&E design. The daylight design of the building is very successful, as the electric lighting needs only to be on 12% of the time during working hours 8.00 – 17.00 with a measured electric lighting consumption of just 0.56 W/m2, which is 25 times lower than the code requirement. The building has a building integrated cooling system consisting of PEX pipes embedded in the concrete floor slabs. This allows the chiller to run during nighttime, to store the cooling in the building structure (19–21°C) as well as in a Phase Change Material (PCM) tank with a 10°C melting point. In addition to being Zero Energy, the building design intent was also to help the national power grid by shifting the building load to night-time and being a next exporter of electricity to the grid during the day-time. This had the added advantage that instead of using a cooling tower, the warm condenser water (36°C) from the chiller was run across the two big BIPV areas and eject the heat from the roof to the "cool" night environment. This way, the solar PV would be cleaned every night and the make-up water to the cooling tower dropped dramatically, because the majority of the heat ejection was through radiation to the night sky and not through evaporation. Due to some issue with the cooling system, it was not possible to maintain the power shifting from day to night and a conventional cooling tower eventually had to be installed.

This pioneering and highly innovative building is a landmark building in Malaysia's energy efficient and green building movement. In fact, when Malaysia's Green Building Index (GBI) was launched in 2009, the GEO building was the only building that qualified to be certified under this green building certification scheme, and as such, became the first GBI certified building in Malaysia.

In 2020, 13 years after its completion, the GEO Building as recognised by the 2020 ASEAN Energy Award, namely as a joint winner in the “Zero Energy Building” category.