How would you structure this "joint venture" deal?

[Kevin Suksi]

We have a deal in principle with another investor and I'm wondering how others have structured similar deals in the past.

This is a retail flip project. The other investor located a short sale and was able to get it under contract where the numbers work. He is funding the purchase of the property. Our role is to fund and execute the rehab. Once sold the profit will be split between the two parties. The numbers all work as far as ARV, rehab cost, etc. We have strong and recent comps within 1/4 mile of the subject property above our target exit price.

My question is - how would you suggest securing our interest as the 2nd investor? I do trust the investor we are entering this deal with but you still want to structure things properly. We aren't bringing funds to the closing, we are funding the rehab as costs are incurred. I am not a builder so I don't think we can lien the property. Any ideas?