Like a wholesale flip just after the renovations

[Kainne Hansbury]

If I like the numbers on a house; Purchase, Renovation costs and After Renovation Value what pitfalls should I be thinking of if I can get the owner to hold onto the house until after I renovate it? I view this as similar to a wholesale flip . I would negotiate the price, draw up the contract that locks me into the purchase price and then I'd close on my purchase and sell the house same day after the renovations were done and a buyer is identified? 

I'd be risking my renovation costs and I know the risks the home owner would be taking. Is there anything I'm missing or a better strategy to get into this house with zero money down if the owner is willing to wait to get their pre-flip purchase price?