I have been asked that if the bank disburses more than half of a construction loan at once at closing are there additional disclosures that need to be provided. I have never heard of this before so I tried to research but found nothing. Am I missing something?

I've never heard of any federal disclosures along this line...and there aren't likely to be state law requirements. The only regulatory issue that jumps out is TIL disclosure calculations--if the loan is consumer credit. If it's consumer credit and TIL disclosures are required and you don't know the dates and amounts of all draws at closing, you have to estimate the interest and the APR. Appendix D is provided as an approved method for those estimates, BUT it's use is limited to cases where there will be an average utilization of the loan amount of 50%. Since all disclosures must be made in good faith using all available information, you can't use Appendix D if you know that it's mathematically impossible to end up with 50% utilization.