Parquet Floor - plywood or flooring grade chipboard

[Vita Vilcina]

Hi there, we will be laying parquet flooring, and in the new extension part builders have installed flooring grade chipboard as the floor, but the rest of the room is floorboards. So we are wondering should we put 12mm plywood across everything, or lift up the rest of the old floorboards and replace them with the same material - flooring grade chipboard. Please see image attached
https://ibb.co/kd05v9

 

[Ernesto]

If you don't have any height restrictions I would add a layer of plywood. You may need to anyways depending on the joist spacing.