How to determine 1031 Construction Value?

[Jonathan Felts]

If I sell my property for $600k and owe $300k on a loan, I walk away with $300k minus agent commission ($30K). If I want to roll that into a fixer 1031 construction loan project, I understand that the property purchase price can be less than the down leg as long as I use the entire $300k profit for the down payment and cap-x improvements. Is that correct? Does the after cap-x value have to be more than my sold property? How is that ARV determined?