Box springs get assumed necessary out of habit, when in practice most modern bed frames and mattresses don't actually require one.
When You Don't Need One
A slatted platform frame like The Poka Bed supports memory foam and hybrid mattresses directly, no box spring required, provided the slats are spaced correctly.
When You Might
Some older-style innerspring mattresses and certain warranty terms still specify a box spring or foundation, worth checking before assuming you can skip it.
The Honest Verdict
Check your mattress manufacturer's requirements first. For most modern mattresses on a slatted platform frame, a box spring is an unnecessary extra cost and added height.
