Fair Percentage for a Silent Non-Recourse Financing Co-Signer?

[Eric M.]

I browsed around a bit but didn't see anything exactly on point, so thoughts welcome.

I am working with a family member, with whom I own a separate property. We will have an LLC. I will be doing ALL of the work, from finding properties, contracting, legal, managing, etc. I also provide 50% of financing.

Family member is a "silent partner." Effectively, he will serve as a co-signer on non-recourse financing. (For example, we intend to apply for a HELOC secured by our jointly owned property). Other than serving as a co-applicant for certain financing, my family member will have no other role.

Question: What percentage of the TOTAL business (profits, eventual equity, etc.) is fair for the family member given this scenario? Stated differently, what percentage of the LLC should he own?

Really appreciate thoughts!