The palace is often at the centre of state occasions and royal hospitality. It is considered to be the world's largest private residence in terms of floor area, earning it the title of "world's largest residential palace".

The name "Istana Nurul Iman" is taken from Malay Istana and Arabic Nur-ol Imaan and means Palace of the Light of Faith. It was designed by Filipino Visayan architect Leandro V. Locsin, who utilized the architectural motif of golden domes and vaulted roofs to echo Brunei's Islamic and Malay influences. The interior of the palace was designed by Khuan Chew, Design Principal of KCA International, whose other works include the Burj Al Arab in Dubai. Construction was handled by Ayala International, a Filipino construction firm, and completed in 1984 at a total cost of around US$1.4 billion.

The title of the "world's largest palace" is difficult to ascertain, and controversial, as different countries use their own unique standard to claim that their palace is the largest. Using various definitions, a number of palaces are claimed to be the world’s largest: Istana Nurul Iman, Buckingham Palace, Quirinal Palace, Royal Palace of Madrid, Stockholm Palace, The Forbidden City, The Palace of Versailles, The Royal Palace of Caserta, The Winter Palace, The Louvre Palace, Prague Castle, and Romania’s Palace of the Parliament.

The palace contains 1,788 rooms, which includes 257 bathrooms, a banquet hall that can be expanded to accommodate up to 5,000 guests, a mosque accommodating 1,500 people. The palace also includes a 110-car garage, an air conditioned stable for the Sultan's 200 polo ponies, and 5 swimming pools. In total, Istana Nurul Iman contains 2,152,782 square feet (200,000 m²) of floorspace. Istana Nurul Iman has 564 chandeliers, 51,000 light bulbs, 44 stairwells and 18 elevators.

According to wikipedia