1st Salle Favart:

"It is a detached building, having the boulevard behind, and a street on each side ; the front is towards a square, upon which part of the Hotel de Choiseul also stood. It is said that this position was given to the theatre at the request of the company for whom it was erected, who were apprehensive that, if the front had been placed in the opposite direction, they would have been assimilated to the acteurs des boulevards.
The front is a portico ninety-six feet wide, formed of six Ionic columns of large proportions, which support an entablature. On the ground floor are five entrances, and at the first floor the same number of windows.

The interior of the edifice presents a vestibule, the ceiling of which is supported by four Doric columns. Two arcades lead to spacious staircases opening into the saloon. This room is decorated with eight grand arcades, of which three, towards the front, form windows opening to a balcony, with a balustrade in stone. The three opposite arcades enclose mirrors. The two others, at the extremities of the saloon, are ornamented with handsome marble chimney-pieces.    From the vestibule two staircases lead to the pit.
The house had originally only three tiers of boxes surmounted by a cornice; but in 1784 the cornice was taken down to form a fourth tier. The ceiling, painted by Renou, was executed with the greatest care. The interior arrangement and ornaments underwent partial changes at several periods; but in 1797 the plan was completely altered under the direction of M. Bienaimé. Since that time the house has remained the same, with the exception of some slight embellishments.

The form of this theatre is an ellipsis of fifty feet by forty. The ceiling is supported by light columns, which separate the boxes of the fourth tier. A fifth tier of boxes has been contrived in the ceiling. The front of the boxes is a ground of white marble, with ornaments in grey and gold. The ceiling is blue, decorated with four figures and two groups in colours, borrowed from the two ceilings of the Villa Adriani; its circumference is composed of arabesques.
The piedroits of the proscenium represent yellow marble, upon which were painted two statues in niches, and above them medallions containing the busts, in imitative bas-relief, of Gretry, Sarti, Guglielmi, and other celebrated composers, but which have recently disappeared. The curtain represents a beautiful blue drapery, which, being looped up, displays some magnificent edifices in Roman architecture. This house will contain nineteen hundred and eighty spectators."

In:  Whittaker, G. B.: The History of Paris from the Earliest Period to the Present Day: Vol. II. London, 1825 p. 494 - 495