How Many Rooms are there in the Forbidden City? 9999.5?

Covering around 720,000 square meters (860,000 square yards), Forbidden City has numerous rooms. How many rooms are there in the Forbidden City exactly? Since ancient times, there is a folk legend that the Forbidden City has 9999.5 rooms in total. However, based on the latest counting, Forbidden City has 9,371 rooms, not the legendary 9,999.5 but very close.
 In ancient China, the emperors considered themselves as Sons of Heaven in order to consolidate their status and political powers. They claimed that their powers were given by Heaven and control the country in accordance with Heaven’s will.

The folklore said that the Heavenly Palace, also called Zi Wei Palace, has 10,000 rooms. The son’s palace cannot exceed the Heaven’s residence. Therefore, when building Forbidden City, the emperor cut the room number and only built 9,999 and a half room, less than but infinitely approaching 10,000. 

However, many palaces inside the Forbidden City were destroyed by the fire and have not been repaired. If adding this part, it is not impossible to have 9999.5 rooms. Although there are not so many rooms in the Forbidden City in reality, the half room does exist. There are two popular viewpoints: 
 It is generally believed that this half room is located at Wen Yuan Hall. Wen Yuan Hall is a very unique building in the Forbidden City. In ancient time, the royal family and nobles pursued symmetry style in architecture and decoration in order to show the solemn of palaces. In general, there is a main room in the middle and equal number of rooms on both sides. Thus the total number of rooms of a hall is always a singular. However, Wen Yuan Hall has 6 rooms (even numbers). But the westernmost room is much smaller than others whose width is only one third of a regular room. People would easily ignore it and only see the rest five rooms which show the symmetrical style. For its small size, this westernmost room in Wen Yuan Hall is considered as the half room. 

However, some scholars don’t agree with it. Although Wen Yuan Hall looks like a building with two stories outside, it actually has three stories inside and even has three to four room-depth. But the westernmost room is just a shallow staircase, not a “room” at all.
 Qianlong Garden, situated at the northwest corner of the Palace of Tranquil Longevity, has a simple building called ‘Yi Zhai’. Nowadays, more and more people believe that the half room is ‘Yi Zhai’. No matter from appearance or from interior, it is divided into one and a half rooms.
 
The name ‘Yi Zhai’ often appears in detached palaces and royal courtyards. It was originally the study room of Emperor Qianlong in his living residence when he was just a prince. After becoming the emperor, Qianlong built many buildings named ‘Yizhai’ in places with beautiful natural scenery, so he could fully enjoy painting and reading. At the same time, he could often recall the memorable time of his youth.

 Palaces Not Open to the Public Yet:
Palace of Established Happiness (Jianfugong)
Palace of Many Splendors (Chonghuagong)
Studio of Cleansing Fragrance (Shufangzhai)

 Further Reading:
How big is the Forbidden City? 
Smallest Palace in the Forbidden City