Yes. Enter them under Supplies. He should report all the income including the reimbursements for parts etc. Then he can deduct them as expenses. Either as Supplies or Other Misc expenses.
Some of the customers have expensive taste, and want all expensive furnishings. So they all get included as income and then deducted as expenses? They can amount to thousands of dollars, not just for 1 project but multiple projects. He also does a markup on them as a contractor. I understand that whatever his profits are, will be taxed. But the numbers will be inflated because some of his projects have a lot of furnishings. Just want to make sure I'm doing the right thing here.