Regards to architecture, Long An Palace is a double roofed house, commonly called "trung luong trung thiem" or "trung thiem diep coc". The front house includes 7 compartments and 2 single wings. The main house consists of 5 compartments and two double wings. The front compartment and main compartment are connected via an elegantly decorated ceiling system commonly called "tran vo cua". Thanks to skillful technique, the entire palace is still a unified space. Compartments in Long An Palace were separated by a bulkhead system and "ram ha" system (raised wooden floor). However, bulkheads were removed as the palace functioned as the library and later museum. Therefore, the space inside Long An Palace looks immense with eight continuous compartments (two front compartments, Vo cua compartment and five main compartments). It was extended by an eave. The double roof architecture made Long An Palace look like a spacious nine-compartment palace. The 1000m2-wide palace was built on a stone foundation which is 1,1m high.
The frame of Long An Palace was made up by hundreds of medium wooden pillars. Pillars were decorated with "con bo" carved at one end of pillars and dougong-shaped console cantilever system. These structures were made on purpose to amaze visitors with decorative patterns at one end of the pillars.
The timber frame system which divides the front palace and the main palace decorated with 1.155 decorative "boxes" following "nhat thi nhat hoa" (one poem, one drawing) and "nhat tu nhat hoa" (one word, one drawing) style. These popular decorative patterns were usually gilded, however, artisans under Thieu Tri reign directly used bone, ivory, pearl, etc on these architectures, creating a simple yet elegant beauty. These boxes are alternately decorated with giant words and Chinese poems which represent for blessings and celebrate national peace. Among 578 poems and words decorated outside Long An Palace, "Vu trung son thuy" and "Phuoc vien van hoi luong da man ngam" written by Emperor Thieu Tri are still a mystery to researchers learning about word rhyme in poems in the old day. Each poem consists of 56 Chinese words arranged in "the hoi van kiem lien hoan", creating 64 poems. Following this decorative method, Nguyen dynasty's artisans successfully combined not only architecture and decoration, but also poem and drawing. This made visitors unable to differentiate between architecture, decoration, art and ideology.
The most special feature of Long An Palace is a system of roof at the front palace. The eight "vi noc" sets are carved and embossed on blocks of wood, creating eight giant skillfully carved "luong long tranh chau" (two dragons fighting over a pearl). This decorative style is different from "chong ruong - gia thu" commonly observed in palaces constructed under Nguyen dynasty. Most of tourists visiting Long An Palace mistake these architectures for artworks. This was what made Long An Palace special. Architecture structures are decorative items at the same time.
Long An Palace is roofed with yin-yang tiles under which placed a dozen of layers of glazed tiles. Its roof is divided into many layers to reduce the load. The top the main house is decorated with dragon holding pearl. The two ends of the roof are decorated with "hoi long" (two dragon turning their backs to each other) pattern. The statues of dragon, unicorn, turtle and phoenix are placed on the four corners of the roof. Pillars placed in front of the palace makes Long An Palace look higher.
Long An Palace is a breakthrough in Nguyen dynasty's architecture. It deserves to be the most typical structure in Hue royal architecture. Long An Palace is an artifact which shows not only poetic beauty, but also the talent of intellectual and skillful artisans. This palace was considered as a master piece where other artworks of Hue Royal Antiquities Museum are on display.
Long An palace was recognized as a national relic on decision 872-QD/BVHTT dated May 12th, 1997 of the Ministry of Culture and Information.