IF you remain living together after a divorce, how much is the party paying support required to pay according to the settlement?

It depends on the language of the separation agreement. You should review it with your lawyer.

If the agreement truly says that payment is only made if you live separately, then no amount is required, under the assumption that while under the same roof you are both sharing expenses, at least as related to the child. If no contribution is being made at all, then you'll need to go back to court and modify the child support provision to remove the "living separately" provision.

Does your divorce decree really make payment contingent on living apart?