The rental rate shoyuld not be based on his payments but the fair market value. His payments may be more or less then (2x) the amount you will have to pay in rent. Perhaps your rental cost will be his total mortgage payment, perhaps 1/4.
Also if it burns you that you will be getting nothing, while he will be biulding equity. The 1st few years of paying down a mortgage takes very little away from the principal, most of the payment in interest, then add taxes and insurance which both don’t help him out in the long run.
I agree. I was trying to impress upon the OP that, whether intentionally or not, his/her proposal was an unfair imposition on the friend. The mortgage payment is only for ownership of the property and land, and does not take into account the costs of maintenance, damage, upkeep, etc. Not to mention the risk that the property might go down in value.
The hyperbole was intentional, but upon reflection I could have made my point in a less inflammatory way.
I know nothing about mortgages or any of that, but perhaps a “fair” agreement would be one similar to what I have with my landlord. I don’t know if this is common to your area, but around here tenants pay the rental price of the apartment (in your case, a reasonable approximation to what goes for rent in your area), and hydro (electricity). The landlord pays heat, water, garbage disposal, snow removal, etc. Additional expenses, such as phone and cable are, obviously, the tenant’s responsibility. Regular maintenance/repairs/pest control are the responsibility of the landlord.
Look into your state housing department, or whatever organization is reponsible for tenant/landlord rules and regulations. Don’t agree to pay for anything that really isn’t your responsibility, because friend or not, he is still your landlord, and his ownership of the place makes certain things his responsibility.