The institute is housed in the erstwhile vice regal lodge which was built in 1884-88 durinng the period of lord Dufferin. It is a commanding building in summer Hill. The gardens of the Institute are really beautiful and fascinating. It was designed by Henry Twain.
The main architect of this stately structure built in the neo-Gothic style, with elements of Scottish Baronial architecture, was Henry Irwin. Spread over 123 acres, it is built in blue-gray stone masonry with tiled-pitch roofing. The main block has three storeys and the kitchen wing five. It is a witness to many events that shaped the history of India. It was the venue for the Shimla conference in 1945. In 1947, the decision on the partition of India and carving out West and East Pakistan was taken here. After independence, it became the property of the President of India and was renamed Rashtrapati Niwas. Now, it houses the Indian Institute of Advanced study (IIAS) where research scholars and fellows from all over the is under the Union Ministry of Human Resource Development.