Where in any regulation, code, or DAU training does it state more affirmatively that construction projects MUST be fully funded?
Below you will find what I think you remember about construction being fully funded. First I found information in the Financial Management Regulation which directed me to OMB Circular A-11. I have bolded the particular part of Section 35 covering construction.
FMR Vol 2B 060502
e. OMB is strictly enforcing the full funding policy contained in OMB) Circular A-11. The Components are required to ensure that all projects are fully funded in compliance with OMB Circular A-11. For large projects that formally would have been considered for incremental funding over multiple years (an increment is not a complete and usable facility), the Components may break projects down into complete and usable phases, with phases in multiple years. OMB’s intent is that incremental funding for construction will be for rare and exceptional cases only. f. In the rare case that OMB grants a waiver to allow for budgeting for the incremental funding of a project, the Components have the flexibility to move funding between increment/years to allow for flexibility but only if there is no increase in the total cost of the project or number of increments. Additional increments or an increase in the total cost of the project requires another waiver request to and approval from OMB. When projects fully funded in a given year’s President’s Budget request are incrementally funded by Congress, the Components should not infer that OMB has agreed to continued incremental funding of the remainder of the project. The Components’ subsequent budget submission should request funding for the full cost of completing the project.
OMB Circular A-11 (2019)
31.5 Full funding Requests for acquisition of capital assets must propose full funding to cover the full costs of the project or a useful segment of the project, consistent with the policy stated in the Capital Programming Guide. Specifically, requests for procurement programs must provide for full funding of the entire cost. In addition, requests for construction programs must provide for full funding of the complete cost of construction.