Thousands of people in mourning clothes first assembled under tents at Wat Thepthidaram, Wat Suthatthepwararam and Benjamarachalai and Bharat Vidyalaya schools, where they were served breakfast while they waited for the plaza to open.
They were required to register for a blue queue card to be presented along with their identification card to gain admission to the plaza.
The reduced-scale replica was among nine erected around greater Bangkok to provide mourners an alternative to crowded Sanam Luang where they could pay their respects.
Every province also had its own replica crematorium.
At Bangkok City Hall, flowers were being laid from 9am to 4.30pm, then halted for the duration of the preliminary cremation ceremonies.
The ritual was to resume at 6.30pm and continue until 10pm, when the actual cremation begins.