Between 2005 and 2007, the National Discovery Museum Institute(NDMI) undertook a project to assess the building's condition, conduct archaeological excavations, and develop exhibition content and display designs.

On December 23, 2007, Her Royal Highness Princess Maha Chakri Sirindhorn presided over the opening ceremony of the Museum Siam building, marking its official inauguration.

Shortly after, when the Siamese Government sought to employ an Italian architect for building consultation, Tamagno was recommended by the Master Technician to accept the position.

During the later years of King Chulalongkorn's reign (Rama V), Tamagno's architectural contributions included the Makkhawan Rangsan Bridge, Abhisek Dusit Throne Hall, Phan Fa Lilat Bridge, Bang Khun PhromPalace, Parusakavan Palace, Amphorn Sathan Villa, Oriental Hotel, The first office if Siam Commercial Bank, Bang Khun Phrom Palace the ceremonial arch for King Rama V's celebration at Niwat Phra Nakhon, Suriyanuwat Villa, Phra Mongkhon Bophit Temple, Waen Si Bridge, and Phyathai Palac.

This original consideration supports the inspection of the building's structure in various aspects, such as the remaining small patches of wall color in different rooms, the wooden floors, and the cooling system.

The restoration process also considers elements such as the construction of the control floor, the herbal water pipe system, the wastewater treatment plant, and the original overflow tank at the front of the building.

Spanning history, architecture, traditions, cuisine, and clothing, the exhibition effectively incorporates cutting- edge technology and creative storytelling methods designed for contemporary audiences and their media preferences.

It seeks to engage visitors by encouraging thoughtful reflection and providing interactive experiences, ensuring they are fully immersed and captivated throughout the entire exhibition.

It is designed like a jigsaw puzzle game where viewers can assemble the cube on a table in the middle of the room and images related to the issues of nation, religion, and monarchy will appear on the display.

A room that gathers together familiar household items that we see in everyday life, which when seen we can immediately tell for sure are definitely Thai, such as condiment bundles, coffee bags tied with rubber bands, crocheted brand name bag handles, Mama noodles of various flavors, including the highlight, Khun Eabsap, a giant NangKwak statue that is over 4 meters tall, etc., which reflects the personality of Thai people who are inventive and improve in order to solve problems in life.

A graphic board invites you to ask questions about Thai dishes with foreign names such as Khanom Jeen, American fried rice, and Tokyo dessert, etc.

Museum Siam has launched a new permanent exhibition titled "Decoding Thainess," designed to educate visitors about the evolution of Thai identity from past to present.

Visitors can engage with interactive displays, such as motion graphics in the "living kitchen" that showcases Thai cuisine, and a virtual classroom reflecting historical educational contexts.