Ceiling Insulation

[u/Crop_11]

I had a feeling that my house didn't have any insulation as it gets extremely hot in summer and really cold in winter. I got up there today and I was right but what surprised me were all the timber flat timber platforms sitting on the ceiling beams.

There are also wires and plugs running throughout the ceiling. I'm wondering if I should just lay the ceiling batts on top or do I need to move the timber platforms and install the insulation beneath so they sit between the joists.