Chatree Ladalalitsakul, National Artist and chief architect of the new parliament building, has opposed several plans to renovate it, calling the structure a major national artwork that should not be altered without the original designers' consent.
"For 10 years, we have remained silent despite the defamation. The parliament is one of the most important architectural works of the nation in the past century. As the designer, I've defended this work for a decade at great personal cost. Now that the project has been handed over, I can no longer protect it.
"I was asked to remain quiet, but I find it deeply frustrating," Mr Chatree said on Thursday when he was in parliament to submit a letter to the Senate subcommittee on creative arts opposing plans for modification.
He noted that four national artists contributed to the design. In architecture, post-completion modifications are rare due to their aesthetic and functional implications. Any such changes must be made with the consent of the original designers.
"This building is a piece of national art. You can't just tack something on wherever you like," he said.
Insufficient parking
Mr Chatree recalled past accusations that the architects failed to comply with legal requirements. In fact, the design adhered to the Terms of Reference (ToR), which were drafted by legal experts, including the then president of the Association of Siamese Architects and officials from the Department of Public Works and Town and Country Planning. These experts knew from the outset that 2,000 spaces would not suffice.
Parking was always intended to be supplemented by nearby military facilities and Wat Kaew Fah.
"It was never meant to be crammed entirely into the parliament complex. During construction, we conducted eight studies on parking, but none were adopted. And now that they want to expand parking, we weren't even informed," he said.
On whether an underground car park extension is feasible, Mr Chatree said he did not know, but warned of flood risks. The parliament's underground levels are protected up to four metres.
"Samsen Road slopes downward. If you walk from the People's Plaza upward, there's a submarine-style water-sealed door. But because the Samsen area is at a lower level, flood protection is weaker there. That said, even if Bangkok is completely submerged, I can confirm the parliament building would remain unaffected," he said.
A fully functional pavilion
Responding to criticism that the Sala Kaeo (the Crystal Pavilion) is too hot and unusable, Mr Chatree clarified that it was designed for two purposes: architectural expression and ceremonial use, like for religious and public ceremonies. Most people are unaware that it includes an electric retractable canvas roof that reflects heat.
The parliament was designed as a space for the people, and claims that the air-conditioning cannot be adjusted are untrue.
"This is a structural sculpture, integral to the landscape, and fully functional -- just not in the way some people wish to use it," he said.
Fill up the pool
In response to claims that the "Emerald Pool", an indoor reflecting pool, is a mosquito breeding ground and prone to leakage, Mr Chatree explained that the pool was designed with a filtration system similar to that used in swimming pools.
With proper maintenance and circulation, mosquito larvae cannot survive. If there is leakage, this would be a fault in construction and should be addressed under the contractor's warranty, especially since the building was only recently handed over.
He also criticised the plan to repurpose the Emerald Pool space into a ground-floor library and commercial area, calling it an unnecessary, irreversible modification that undermines both form and function.
The Emerald Pool plays a vital role in regulating the temperature in the central atrium. Removing it could compromise the building's cooling design, potentially requiring costly air-conditioning retrofits.
"The atrium is as tall as a 10-storey building and open on all sides. Installing AC would be prohibitively expensive. Enclosing it with glass or installing glass barriers on the 2nd to 4th floor walkways surrounding the courtyard would be exorbitantly expensive," he said.
Relocating the library to the ground floor is unjustifiable, involving unnecessary costs in exchange for irreversible damage that is disproportionate to the perceived benefit.
Structural safety at risk
Mr Chatree expressed concern that altering the structure and modification plans, such as changing the Emerald Pool for a library, could affect the building's earthquake resistance and structural integrity. Additional loads from new construction may weaken the original framework, especially if done without input from the original engineering team.
"The structural system was designed to handle specific loads. Adding heavy library stacks or closing water features changes that balance. New designers must bear legal responsibility," he said.
Architectural heritage
Mr Chatree warned that the proposed modifications would irreparably damage a national landmark intended to endure for generations.
He described the parliament complex as more than a functional space -- it embodies Thai aesthetics, cultural identity, and the spirit of national craftsmanship inherited from previous generations.
"It is a piece of national art. You can't just tack something on wherever you like," he said. The building was designed to last a hundred years and showcase Thailand's unique contemporary design on the global stage.
Mr Chatree also said that the original design was valued at around 11 billion baht, later adjusted to about 12 billion baht. (However, the parliament was built with a budget of 22 billion baht.)
"Beyond that, we have had no involvement, and we disagree with many things," he said.