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What things should I consider when getting a joint-mortgage?
The first and most important thing to consider is that this is a BUSINESS TRANSACTION, and needs to be treated as such. Nail down Absolutely All The Details, specifically including what happens if either of you decides it's time to move and wants to sell off your share of the property. Get at least one lawyer involved in drawing up that contract, perhaps two so there's no risk of conflict of interest. What's your recourse, or his, if the other stops making their share of the payments? Who's responsible for repairs and upkeep? If you make renovations, how does that affect the ownership percentage, and what kind of approval do you need from him first, and how do you get it, and how quickly does he have to respond? If he wants to do something to maintain his investment, such as reroofing, how does he negotiate that with you -- especially if it's something that requires access to the inside of the house? Who is the insurance paid by, or will each of you be insuring it separately? What are the tax implications? Consider EVERY possible outcome; the fact that you're friends now doesn't matter, and in fact arguments over money are one of the classic things that kill friendships. I'd be careful making this deal with a relative (though in fact I did loan my brother a sizable chunk of change to help him bridge between his old house and new house, and that's registered as a mortgage to formalize it). I'd insist on formalizing who owns what even with a spouse, since marriages don't always last. With someone who's just a co-worker and casual friend, it's business and only business, and needs to be both evaluated and contracted as such to protect both of you. If you can't make an agreement that you'd be reasonably comfortable signing with a stranger, think long and hard about whether you want to sign it at all. I'll also point out that nobody is completely safe from long-term unemployment. The odds may be low, but people do get blindsided. The wave of foreclosures during and after the recent depression is direct evidence of that.