Bangkok will be home to the world’s largest parliament complex, after almost eight years and Bt22.9 billion was spent on its construction, when it is officially open in May.

This is the meeting place of the upper house, (the Senate of Thailand), and the lower house, (the House of Representatives of Thailand), the two houses of the National Assembly of Thailand.
There are also museums, a convention centre, a seminar room, a banquet hall, offices and more.
The complex, officially called “Sappaya Sapasathan,” covers a floor area of 424,000 square metres, knocking Romania’s 365,000sqm Palace of the Parliament off the top of the list of the world’s largest legislatures.

Thailand’s new Parliament complex is also the world’s second-largest administrative building after the Pentagon, headquarters of the US Department of Defence, which has a colossal floor area of 620,000sqm.
Sappaya Sapasathan, which means “place of assembly for good deeds,” is scheduled to officially open its doors in early May, according to the House of Representatives secretary-general Pornpit Petchcharoen. However, parliamentarians have been using the premises for meetings since August 2019 despite ongoing construction work.
This is Thailand’s third parliament complex since the advent of the constitutional monarchy in 1932. The Ananta Samakhom Throne Hall was home to the Kingdom’s first Parliament from 1933 until 1974. Then, lawmakers shifted to Parliament House next to Dusit Zoo. This was used until late 2018.
In July 2008, the Samak Sundaravej-led government began looking for larger premises. Of the three venues proposed, the government opted for a 120-rai plot on the bank of the Chao Phraya River.

Construction commenced in June 2013, and the once-sleepy neighbourhood transformed into a buzzing community. It sits on a bank of the Chao Phraya River in Kiakkai neighbourhood of the Thanon Nakhon Chai Si Subdistrict, occupying 300,000 m2 of land. The site of the previous parliament building was returned to its owner, the Bureau of the Royal Household, at the end of 2018.
A new bridge is being constructed nearby, while roads in the vicinity are being expanded. An MRT Purple Line extension serving Parliament is scheduled for completion in 2026, while a river pier is being built out from the complex.
The new Parliament can accommodate over 5,000 people and has parking space for more than 2,000 cars. The complex is almost three quarters the size of Thailand’s main airport, Suvarnabhumi, which covers a whopping 563,000sqm.
The building was initially scheduled for completion in 2015 at a cost of Bt14 billion. However, problems brought delays that mounted to more than five years while the cost ballooned to Bt22.9 billion.

The complex is based on the winning design of a team led by National Artist Theerapol Niyom. Topped by a golden pagoda, it features the 800-seat Suriyan (Sun) Hall for the House of Representatives, the 300-seat Chantra (Moon) Hall, constructed with wood from 5,018 teak trees to represent the “DNA of Thailand”.

The complex also boasts 110 rooms for committee meetings, six 250-seat meeting rooms, and a 1,500-seat VIP reception hall, as well as the Museum of Democracy showcasing Thailand’s political history.
The central golden pagoda represents Sumeru or Mount Meru, a mythical mountain considered to be the centre of the universe in Hindu and Buddhist beliefs.
The pagoda was designed by architects Pinyo Suwankiri and Phao Suwansaksri, both National Artists and experts in Thai heritage.
Below the steeple is the Hall of State Ceremonies reserved for the ceremonial opening of Parliament by HM the King after every general election.
The hall’s interior is decorated with murals painted by artists working under the Department of Fine Arts. The murals depict stories from Thailand’s four regions and also record contemporary events, including the pandemic.