I know it's too late for you, but for the benefit of future readers, I'll say it first: This should have been addressed in the contract that was signed before the project began.

If there is a bank loan involved in this project, the bank is going to have input into the payment schedule.

You shouldn't pay in advance for any work that is not done. And a reasonable holdback on what is done (maybe 10%). That's my opinion.

Others who are involved in this type of work more often will give us both a better perspective.

Draws should be based upon incremental stages. A homeowner is going to want those measures to be upon completion (draw after foundation, draw after rough framing, draw after drywall, etc.) while a contractor is going to want work to not continue until the draw is paid. This is probably more fair, as completion of a particular increment may not be possible through no fault of the contractor.

It's not too late to work out mutually agreeable draw schedule. And 10% retainage at completion isn't unreasonable.