New Delhi, July 30 (IANS): The ministry of external affairs' Jawaharlal Nehru Bhawan here Tuesday became the first government building in the country to bag a Gold Rating Certificate for being energy efficient and sticking to green building norms.

The certificate was handed over to outgoing Foreign Secretary Ranjan Mathai.

Addressing the gathering, which included his successor Sujatha Singh, Mathai said the process to turn Jawaharlal Nehru Bhawan into a green building had been both an "interesting and challenging" task.

Receiving the plaque and certificate from the Indian Green Building Council, Mathai hoped the Jawaharlal Nehru Bhawan would strive for platinium certificate.

Mathai also took a gentle parting shot at the PMO and the defence ministry over most of MEA being "packed off" from South Block to Akbar Bhawan, saying he said he did not want to remember the time in 1985 when this was done by the "irresistible force of the PMO (prime minister's office)" and the "immovable MOD (ministry of defence).