There is NO LEGAL REQUIREMENT.
HOWEVER... The operator must not sink below the MDA(H) on any Non precision approach.
Almost all European non precision approaches have now a DA iso. an MDA.
This however does not mean that you can go below the published DA minima. It depends on the issuer of your charts, but Jeppesen for example does NOT provide any blanket for go around loss of altitude at DA at a CANPA approach. It is up to the operator to decide which extra altitude to add to the published minima in order to avoid a bust.
There are some EASA members that require an extra altitude, for example, France requires that you add on Jeppesen CANPA approaches at least 40'.
In my company, we use 50ft. add-on to the published DA. We use Jeppesen.