Can I defer taxes this way?

Hello everyone, I was just recently hired at a real estate development company to clean up their accounting. They have had a bad history with the accounting and finance department and have gone through a numerous number of accountants and finance professionals within the past year. I'm sure you can imagine what the condition of the books are like... NOT GOOD. To give a backstory, the company has different projects that are set up as individual LLC's. The projects consist of the development and then eventually, the final sale of condos/lofts. A project is not closed until the final unit is sold. We have a construction loan from a lender that is to cover the entire cost of the project. The stipulation with the lender is that as units are sold, the entire sale amount is given directly to the bank to pay down the loan. Essentially, we will not see cash until the loan is paid down in full. We have no expenses because all the expenses are capitalized as WIP. Once a unit is sold, the portion of WIP that is the cost for that unit must be closed out and booked to inventory. The entry would be: Inventory Dr. cost of the unit (to reflect the increase in inventory) WIP Cr. cost of the unit (to reflect the portion of WIP closed to inventory) The two entries to reflect the sale would be: 1. Loan Liability Dr. unit sales revenue (to reduce the loan balance) Income Cr. unit sales revenue (to reflect the sale of the unit) 2. COGS Dr. cost of the unit (to expense the cost of the unit) Inventory Cr. Cost of the unit (to reduce inventory) Income – COGS = Net Income, which is taxable. Straight forward right? I run into a couple problems here that give me a massive headache. The first problem is, there is one WIP account for the entire project. The units were not job costed (shame on the previous accountants), so I have no idea what the cost of each individual unit is. I only know the cost to date of the entire project. I have no way of determining the COGS for an individual unit. The second problem is, even if I did know the COGS per unit, I will not have the cash flow to pay the tax liability for the net income recognized after the sale of the unit because the bank takes everything until the loan is paid down in full. So, to handle both issues, is it appropriate to book the COGS of the unit as the entire sales price of the unit to show a zero-net income for the year to defer taxes, and then when WIP/Inventory is eventually expensed in full and closed out, book the remaining sale amounts as income (with no/very little COGS) and pay the tax on that in the final year(s)? I know the tax liability will be bigger because the entire COGS (or most of it) was taken in previous years to wipe out the revenue to defer tax until the loan balance is paid down in full and there is cash flow, but this is the only way I can see this being done. Is this acceptable in terms of tax law and GAAP? Thank you so much for your help.