It would appear that Queen Victoria had an annexe to the Abbey for her Coronation. This from 'Victoriana Magazine':

"Arrival at the Abbey — On the arrival of the procession at the west entrance to the Abbey Her Majesty was received by the great Officers of State, the Noblemen bearing the Regalia, and the Bishops carrying the Patina, the Chalice, and the Bible, when Her Majesty repaired to her robing-chamber, constructed on the right of the platform without the entrance. In front of the grand western entrance to the Abbey, a beautiful Gothic edifice was erected, the style of architecture being perfectly in accordance with the antiquity of the Abbey itself. On entering the porch of this edifice, the same Gothic character was found to be beautifully preserved. On the right and left of the porch were the reception-rooms of Her Majesty and the members of the Royal Family. These chambers were entered through oaken doors, beautifully carved; that on the right was set apart for Her Majesty, and was entered through an anti-chamber, in which her attendants remained.

The walls of Her Majesty's chamber were covered with crimson paper, with Gothic panels and cornices, and lighted by two windows. From this chamber a Gothic-arched door led to a retiring room. The furniture of this room was all of oak, beautifully carved and gilt; and the hangings, carpets, and other fitments, all preserved the same appearance of antiquity. Her Majesty, having been robed, then advanced up the nave into the choir; the choristers in the orchestra singing the anthem, "I was glad when they said unto me; we will go into the house of the Lord."

The 1953 annexe was very contemporary in its design. I'm trying to find pictures of annexes from other coronations.

Interesting that the Duchess of Cambrige, or Catherine Middleton as she was then had that Coronation anthem at her wedding.