By a law of August 8th.1854, the Government authorized to erect, in these lands, the Building of the National Congress, beginning its works in 1857, after the demolition of the Institute.

 The planes of the building of the National Congress are labor of the famous French architect Claude Francois Brunet des Baines, whom was seconded by his colleague M. Lucien Henault, who completed it. They were firstly reversed, $150,000, sum that only reached to construct the walls of the first floor and part of the hewing stone. The land occupying the Church of the Company, destroyed by a fire on December 8th. 1863, was destined to gardens.

Two years later, in 1872, the Government accepted a proposal of Mr. Eduardo Trait, in order to introduce new modifications to the project of the building and to use better materials than the consulted ones, propose that reached to the sum of $ 800,000.-Mr. Trait concluded satisfactorily his work, that was received by the Government architect Mr. Eusebio Chelli, who had replaced Mr. Aldunate.The total cost of the construction of the Palace of Congress was about $ 950,000. -, to which it is necessary to add $ 300,000, - that costed its furniture, which finally adds $ 1,250,000.-

The furniture, lamps and the works of art were acquired in Europe by the Consul of Chile in Paris, Mr. Francisco Rodella and, as it writes down a journalist of the time, it accused " a severe, simple and comfortable taste and perfectly adapted to the service that it was destined for ".

Armchairs, tables, writing-desks and shelves were made of mahogany, or walnut of first class.

The building, that occupies a rectangle of 76 meters wide and 78 meters bottom, was inaugurated during the administration of Don Federico Errázuriz, who on June 1st. 1876, who addressed the Message opening the ordinary sessions period in the great Honor Hall of that building.

Once finished the ceremony, the public invaded the dependencies of the Palace of the Congress, " admiring the comfort and the good taste of the facilities ". From that date the Senate and the House of Representatives began to session in their new building, leaving the old one of the O'Higgins square.Unfortunately, around the 1,35 of the night on May 18th. 1895, a voracious fire exploded in the building of the National Congress and destroyed great part of it.

The newspaper " the Railroad " wrote in its holders, with enormous letters, while informing this event: " Colossal fire.The building of the Congress, devoured by the fire. Enormous losses. A palace in ruins. The Library, the archives and all the furniture consumed by the flames. The offices of the Direction of Public Work totally burned... ".

Quickly the Senate and the House of Representatives were mentioned to sessions, on the following day, meeting at the Hall Honor of the University of Chile.After that fire, the House of Representatives provisory domiciled at the University House, wasting in it the sum of $20.000. The Senate, on the other hand, did it in the fiscal building which the Societies of Mining and Manufacturing Promotion occupied, spending $17,000 in settling.The total completion of the works of reconstruction, happened in 1900.