I have an existing concrete patio that's in decent condition (needs power wash but no cracks and original to the house in 2003 so it seems to have been built properly). It is surrounded by a 6' wide strip of pavers and that is surrounded by a 3' wide mulch bed with a 2' height difference from the adjacent lawn.

Ideally i would take up the existing pavers, lay a gravel base to raise up that level to match with the concrete (with an appropriate slope of course) and then lay all new pavers over the whole thing to have one consistent patio with continuous steps down to the lawn on the other side.

My question is, considering the condition of the concrete. is it ok for me to just lay a 1" sand base over it and lay 4" gravel + 1" sand over the area where the brick pavers are located now.

Overall look should be something similar to below.