I am remodeling my kitchen and have taken down a wall to include a small addition that was built by the previous homeowner as a TV room. the problem I have is that the sub floors from their addition and the original kitchen is about 3/32 to 1/8" of an inch different (lower). I was trying to think of a good method to raise the level to make them even as we are planning to put down a prefinished wood floor.
What I was thinking was to put enough layers of rosin paper on the 10x8 lower section to make it level and then put 1/4" luan over everything. Will this feel spongy?
Anyone have any good suggestions since the difference is so small.

Thanks in advance.