How do I calculate ownership percentage for shared home ownership?
"Sister is putting down nothing, and paying sub-market rent. It looks to me like if she is assigned anything, it's a gift.  You on the other hand, have put down the full downpayment, and instead of breaking even via fair rent, are feeding the property to the tune of $645/mo.  In the old days, the days of Robert Allen's ""no money down"" it was common to see shared equity deals where the investor would put up the down payment, get 1/2 the equity build up, and never pay another dime. This deal reminds me of that, only you are getting the short end of the stick.  ""you never think something will cause discourse"" - I hope you meant this sarcastically. The deal you describe? No good can come of it." "Accounting for this properly is not a trivial matter, and you would be wise to pay a little extra to talk with a lawyer and/or CPA to ensure the precise wording. How best to structure such an arrangement will depend upon your particular jurisdiction, as this is not a federal matter - you need someone licensed to advise in your particular state at least. The law of real estate co-ownership (as defined on a deed) is not sufficient for the task you are asking of it - you need something more sophisticated. Family Partnership (we'll call it FP) is created (LLC, LLP, whatever). We'll say April + A-Husband gets 50%, and Sister gets 50% equity (how you should handle ownership with your husband is outside the scope of this answer, but you should probably talk it over with a lawyer and this will depend on your state!).  A loan is taken out to buy the property, in this case with all partners personally guaranteeing the loan equally, but the loan is really being taken out by FP. The mortgage should probably show 100% ownership by FP, not by any of you individually - you will only be guaranteeing the loan, and your ownership is purely through the partnership. You and your husband put $20,000 into the partnership. The FP now lists a $20,000 liability to you, and a $20,000 asset in cash. FP buys the $320,000 house (increase assets) with a $300,000 mortgage (liability) and $20,000 cash (decrease assets). Equity in the partnership is $0 right now. The ownership at present is clear. You own 50% of $0, and your sister owns 50% of $0. Where'd your money go?! Simple - it's a liability of the partnership, so you and your husband are together owed $20,000 by the partnership before any equity exists. Everything balances nicely at this point. Note that you should account for paying closing costs the same as you considered the down payment - that money should be paid back to you before any is doled out as investment profit! Now, how do you handle mortgage payments? This actually isn't as hard as it sounds, thanks to the nature of a partnership and proper business accounting. With a good foundation the rest of the building proceeds quite cleanly. On month 1 your sister pays $1400 into the partnership, while you pay $645 into the partnership. FP will record an increase in assets (cash) of $1800, an increase in liability to your sister of $1400, and an increase in liability to you of $645. FP will then record a decrease in cash assets of $1800 to pay the mortgage, with a matching increase in cost account for the mortgage. No net change in equity, but your individual contributions are still preserved. Let's say that now after only 1 month you decide to sell the property - someone makes an offer you just can't refuse of $350,000 dollars (we'll pretend all the closing costs disappeared in buying and selling, but it should be clear how to account for those as I mention earlier). Now what happens? FP gets an increase in cash assets of $350,000, decreases the house asset ($320,000 - original purchase price), and pays off the mortgage - for simplicity let's pretend it's still $300,000 somehow. Now there's $50,000 in cash left in the partnership - who's money is it? By accounting for the house this way, the answer is easily determined. First all investments are paid back - so you get back $20,000 for the down payment, $645 for your mortgage payments so far, and your sister gets back $1400 for her mortgage payment. There is now $27,995 left, and by being equal partners you get to split it - 13,977 to you and your husband and the same amount to your sister (I'm keeping the extra dollar for my advice to talk to a lawyer/CPA). What About Getting To Live There? The fact is that your sister is getting a little something extra out of the deal - she get's the live there! How do you account for that? Well, you might just be calling it a gift. The problem is you aren't in any way, shape, or form putting that in writing, assigning it a value, nothing.  Also, what do you do if you want to sell/cash out or at least get rid of the mortgage, as it will be showing up as a debt on your credit report and will effect your ability to secure financing of your own in the future if you decide to buy a house for your husband and yourself?  Now this is the kind of stuff where families get in trouble. You are mixing personal lives and business arrangements, and some things are not written down (like the right to occupy the property) and this can really get messy. Would evicting your sister to sell the house before you all go bankrupt on a bad deal make future family gatherings tense? I'm betting it might. There should be a carefully worded lease probably from the partnership to your sister. That would help protect you from extra court costs in trying to determine who has the rights to occupy the property, especially if it's also written up as part of the partnership agreement...but now you are building the potential for eviction proceedings against your sister right into an investment deal? Ugh, what a potential nightmare! And done right, there should probably be some dollar value assigned to the right to live there and use the property. Unless you just want to really gift that to your sister, but this can be a kind of invisible and poorly quantified gift - and those don't usually work very well psychologically. And it also means she's going to be getting an awfully larger benefit from this ""investment"" than you and your husband - do you think that might cause animosity over dozens and dozens of writing out the check to pay for the property while not realizing any direct benefit while you pay to keep up your own living circumstances too? In short, you need a legal structure that can properly account for the fact that you are starting out in-equal contributors to your scheme, and ongoing contributions will be different over time too. What if she falls on hard times and you make a few of the mortgage payments? What if she wants to redo the bathroom and insists on paying for the whole thing herself or with her own loan, etc? With a properly documented partnership - or equivalent such business entity - these questions are easily resolved. They can be equitably handled by a court in event of family squabble, divorce, death, bankruptcy, emergency liquidation, early sale, refinance - you name it. No percentage of simple co-ownership recorded on a deed can do any of this for you. No math can provide you the proper protection that a properly organized business entity can. I would thus strongly advise you, your husband, and your sister to spend the comparatively tiny amount of extra money to get advice from a real estate/investment lawyer/CPA to get you set up right. Keep all receipts and you can pay a book keeper or the accountant to do end of the year taxes, and answer questions that will come up like how to properly account for things like depreciation on taxes. Your intuition that you should make sure things are formally written up in times when everyone is on good terms is extremely wise, so please follow it up with in-person paid consultation from an expert. And no matter what, this deal as presently structured has a really large built-in potential for heartache as you have three partners AND one of the partners is also renting the property partially from themselves while putting no money down?  This has a great potential to be a train wreck, so please do look into what would happen if these went wrong into some more detail and write up in advance - in a legally binding way - what all parties rights and responsibilities are." It may clarify your thinking if you look at this as two transactions: I am an Australian so I cannot comment on US tax laws but this is how the Australian Tax Office would view the transaction. By thinking this way you can allocate the risks correctly, Partnership Tenancy Two things should be clear - you will need a good accountant and a good lawyer - each. "The bottom line is that you can decide whatever you want to do.  It is good of you to get everything in writing.  What happens if she decides to move to a different city?  What happens if she also wants to be bought out?  It should also include contingencies for your husband and yourself.  God forbid anything negative happens, but what happens if you two get divorced?  Does your husband want to be an agreement with your sister if you pass away? There does not seem to be any math to do in this case.  While she is paying the lion's share of the payment, she is also receiving the benefit of having a place to live.  It is unlikely that she can rent an equivalent place for anything close to 1400/month.  I would estimate it would be at least 1800/month to rent an equivalent property. So she put no money down, and she is paying below market ""rent"" to live somewhere.  Many people would be happy to have $400/month off and handle their own repairs (let alone you still kicking in half).   Now all that said, if you want to give her some equity based upon generosity or the desire to give her some dignity, then you are free to do so.  Perhaps 10%?" You and your husband are fronting all the money upfront. I'm guessing this will cost you around 67,000 once closing costs and fees are included. So obviously you would be hundred percent owners at the beginning. You'll then pay 31% of the mortgage and have your sister pay the remaining 69%. This puts your total investment at the end at 67k + 74.4k + 31% of interest accrued, and your sisters total investment at 165.6k+69% of interest accrued. If you hold the full length of the mortgage, your sister will have invested much more than you( assuming 30 year fixed rate, and 3.75%, she'd pay 116.6k in interest as opposed to your 49.6k) She will have spent 282.2k and y'all will have spent 191k. However if you sell early, your percentage could be much higher.  These calculations don't take into account the opportunity cost of fronting all the cash. It could be earning you more in the stock market or in a different investment property. Liability also could be an issue in the case of her not being able to pay. The bank can still come after you for the whole amount. Lastly and most importantly, this also doesn't include the fact that she will be living there and y'all will not. What kind of rent would she be paying to live in a similar home? If it is more than 1400, you will basically be subsidizing her living, as well as tying up funds, and increasing your risk exposure. If it is more than 1400, she shouldn't be any percent owner. Once your sister and you make your first payments, you've paid $20,645, and your sister has paid $1400. But your sister also owes rent. Zeroth order estimate for rent is that it's equal to mortgage payment, so that's $2045 (I assume that $2045 is actually your total payment, not just your escrow payment. Unless I'm misunderstanding what the term means, $2045 is an absurdly high amount for a monthly escrow payment.) So your sister now has made a net capital contribution of ... negative $645. So you're giving your sister a gift of $7740 each year, and are the sole equity owner of the house. There's a $14000/year gift tax exclusion, and I think that both you and your husband can claim it separately, so every year you could declare your sister to have $20260 added to her capital contribution, or more if you're willing to pay gift tax. But as it stands, if there are any losses from the property, they will be borne exclusively by you; therefore, any profits should be enjoyed exclusively by you. Any other arrangement is you giving a gift to your sister. If the price of the house were to shoot up to $1,000,000 after a year, and you were to split the profits with your sister 50:50, and not pay a gift tax, you WOULD be violating tax law.
i would recommend that you establish a landlord/tenant relationship instead of joint ownership (ie 100% ownership stake for one of you vs 0% for the other). it is much cleaner and simpler.  basically, one of you can propose a monthly rent amount and the other one can chose to be either renter or landlord. alternatively, you can both write down a secret rental price offer assuming you are the landlord, then pick the landlord who wrote down the smaller rental price.  if neither of you can afford the down payment, then you can consider the renter's contribution an unsecured loan (at an agreed interest rate and payment schedule). if you must have both names on the financing, then i would recommend you sell the property (or refinance under a single name) as quickly as possible when the relationship ends (if not before), pay the renter back any remaining balance on the loan and leave the landlord with the resulting equity (or debt).  in any case, if you expect the unsecured loan to outlive your relationship, then you are either buying a house you can't afford, or partnering on it with someone you shouldn't. You should have drafted a contract of purchase that stipulated out equity stake in the home based of his down payment and yours, along with future monthly payments.  But morally, if the house sells, yielding 100,000 profit (after fees/taxes/etc), you should get ( To Calculate Your Cut: (20,000 + Your Total Mortgage Payments Applied to Principle) / (1,900 + His Total Mortgage Payments Applied to Principle Only) * Profit on Sale of House After All Fees = Your Cut His would be: (1,900 + His Total Mortgage Payments Applied to Principle Only) / (20,000 + Your Total Mortgage Payments Applied to Principle) * Profit on Sale of House After All Fees = His Cut You'd then take mortgage payment totals for each; and calculate the payments made towards interest; and claim the correct amount each of you paid on payments for the mortgage interest deduction when you file your taxes. Although, depending on how the loan is written, the banks may issue 1099s which dont reflect actual payments made... Talk to an accountant. "With regard to worries about ownership:  I'll point you towards this - The Cohabitants Rights Bill currently in First Reading at the House of Lords. Without a date for even the second reading yet. In short the Bill is attempting to redress is the lack of rights when a non-married relationship ends when compared to married relationships; that is that one of the ""cohabitants"" can end up with basically nothing that they don't have their name on. So currently you're in the clear and (Part 2) Section 6.2.a says the Bill cannot be used retroactively against you if your relationship is over before it becomes law (I expect with Brexit etc, this Bill isn't a high priority - it's been a year since the first reading). Section 6.2.a: This Part does not apply to former cohabitants        where the former cohabitants have ceased living together as a        couple before the commencement date;    However, if you're still together if/when this Bill becomes Law then basically all of (Part 1) Section 2 may be relevant as it notes the conditions you will fall into this bill: Section 2.1.a: live together as a couple and Section 2.2.d: have lived together as a couple for a continuous        period of three years or more. and the ""have lived together"" at that point counts from the start of your cohabitation, not the start of the Bill being law:  Section 2.4.a: For the purposes of subsection (2)(d), in determining        the length of the continuous period during which two people have lived       together as a couple - any period of the relationship that fell before        the commencement date (of the Bill) is to be taken into account If you have kids at some point, you'd also fall under 2.2.a through 2.2.c too. After that, the financial parity decided upon by the court depends on a whole bunch of conditions as outlined in the Bill, but Section 8.1.b is pretty clear: Section 8.1.b: (b)the court is satisfied either—       (i)that the respondent has retained a benefit; or       (ii)40that the applicant has an economic disadvantage,       as a result of qualifying contributions the applicant has made I'm not qualified to say whether your partner helping to pay off your mortgage in lieu of paying rent herself would count as just paying rent or giving you an economic benefit. Sections 12, 13, and 14 discuss opt-outs, also worth a read. The a major disclaimer here in that Bills at this early stage have the potential to be modified, scrapped and/or replaced making this info incorrect. As an additional read, here's an FT article from Feb 2016 discussing this lack of rights of a cohabitant which should alleviate any current concerns." You can either borrow money... credit card, line of credit, re-finance your home, home equity line of credit, loan, mortgage, etc. Or you have other invest in your company as equity.  They will contribute $X to get Y% of your company and get Z% of the profits.  Note amount of profits does not necessarily have to equate to percentage owned.  This makes sense if they are a passive investor, where they just come up with the money and you do all the work.  Also voting rights in a company does not have to equate to percentage owned either. You can also have a combination of equity and debt.  If you have investors, you would need to figure out whether the investor will personally guarantee the debt of your company - recourse vs non-recourse.  If they have more risk, they will want more of a return. One last way to do it is crowdfunding, similar to what people do on Kickstarter.  Supporters/customers come up with the money, then you deliver the product.  Consulting practices do something similar with the concept of retainers. Best of luck. It sounds like you are in great shape, congratulations! Things I would think about in your position: Consider putting 20% down instead of 30% and find a great house that has a key missing modernization, like a kitchen. Then replace the kitchen, which if done right can instantly add that 10% (or more) right back in equity... or stick to your plan... You have earned the luxury of taking your time and doing what's right for you. Think real carefully about location. Here are some ideas based on my experience. "To expand on what @fishinear and some others are saying:  The only way to look at it is that the parents have invested, because the parents get a % of the property in the end, rather than the original loan amount plus interest.  It is investment; it is not a loan of any kind.  One way to understand this is to imagine that after 20 years, the property triples in value (or halves in value).  The parents participate as if they had invested in 75% ownership of the property and the OP as if 25% ownership of the property. Note that with a loan, there is a (potentially changing) outstanding loan balance, that could be paid to end the loan (to pay off the loan), and there is an agreed upon an interest rate that is computed on the outstanding balance — none of those apply to this situation; further with a loan there is no % of the property: though the property may be used to secure the loan, that isn't ownership. Basically, since the situation bears none of the qualities of a loan, and yet does bear the qualities of investment, the parents have bought a % ownership of the property. The parents have invested in 75% of the real estate, and the OP is renting that 75% from them for: The total rent the OP is paying the parents for their 75% of the property is then (at least) $1012.50/mo,  A rental rate of $1012.50/mo for 75% of the property equates to a rental price of $1350/mo for the whole property. This arrangement is only fair to both parties when the fair-market rental value of the whole property is $1350/mo; it is unfair to the OP when the fair-market rental value of property is less, and unfair to the parents when the fair-market rental value of property is more.   Of course, the fair-market rental value of the property is variable over time, so the overall fairness would need to understand rental values over time. I feel like this isn't actually a loan if I can never build more equity in the condo. Am I missing something? No, it isn't a loan.  You and your parents are co-investing in real estate.  Further, you are renting their portion of the investment from them. For comparison, with a loan you have 100% ownership in the property from the start, so you, the owner, would see all the upside/downside as the property valuation changes over time whether the loan is paid off or not. The borrower owes the loan balance (and interest) not some % of the property.  A loan may be secured by the property (using a lien) but that is quite different from ownership.  Typically, a loan has a payment schedule setup to reduce the loan balance (steadily) over time so that you eventually pay it off.  With a loan you gain equity % — the amount you own outright, free & clear — in two ways, (1) by gradually paying off the loan over time so the unencumbered portion of the property grows, and (2) if the valuation of the property increases over time that gain in equity % is yours (not the lenders).  However note that the legal ownership is all 100% yours from the start. Are my parents ripping me off with this deal that doesn't allow me to build my equity in my home? You can evaluate whether you are being ripped off by comparing the $1350/mo rate to the potential rental rate for the property over time (which will be a range or curve, and there are real estate websites (like zillow.com or redfin.com, others) to help estimate what fair-market rent might be). Are there similar deals like this...?  A straight-forward loan would have the borrower with 100% legal ownership from the start, just that the property secures the loan.  Whereas with co-investment there is a division of ownership % that is fixed from the start.   It is unusual to have both investment and loan at the same time where they are setup for gradual change between them.  (Investment and loan can certainly be done together but would usually be done as completely separate contracts, one loan, one investment with no adjustment between the two over time.) To do both investment and loan would be unusual but certainly be possible, I would imagine; however that is not the case here as being described.  I am not familiar with contracts that do both so as to take over the equity/ownership/investment over time while also reducing loan balance.  Perhaps some forms of rent-to-own work that way, something to look into — still, usually rent-to-own means that until the renter owns it 100%, the landlord owns 100%, rather than a gradual % transfer over time (gradual transfer would imply co-ownership for a long time, something that most landlords would be reluctant to do).   Transfer of any particular % of real estate ownership typically requires filing documents with the county and may incur fees.  I am not aware of counties that allow gradual % transfer with one single filing.  Still, the courts may honor a contract that does such gradual transfer outside of county filings. If so, what should I do? Explain the situation to your parents, and, in particular, however far out of balance the rental rate may be.  Decide for yourself if you want to rent vs. buy, and where (that property or some other).  If your parents are fair people, they should be open to negotiation.  If not, you might need a lawyer.   I suspect that a lawyer would be able to find several issues with which to challenge the contract. The other terms are important as well, namely gross vs. net proceeds (as others point out) because selling a property costs a % to real estate agents and possibly some taxes as well. And as the others have pointed out, if the property ultimately looses value, that could be factored in as well. It is immaterial to judging the fairness of this particular situation whether getting a bank loan would be preferable to renting 75% from the parents.  Further, loan interest rates don't factor into the fairness of this rental situation (but of course interest rates do factor into identifying the better of various methods of investment and methods of securing a place to live, e.g. rent vs. buy). Contributed by @Scott: If your parents view this as an investment arrangement as described, then you need to clarify with them if the payments being made to them are considered a ""buy out"" of their share. This would allow you to gain the equity you seek from the arrangement. @Scott: Terms would have to be (or have been) declared to that effect; this would involve specifying some schedule and/or rates.  It would have to be negotiated; this it is not something that could go assumed or unstated.  -- Erik" You say that one property is 65% of the value of the two properties and the other is 35%.  But how much of that do the two of you actually own?  If you have co-signed mortgages on both properties, then your equity is going to be lower.  If you sold both properties, then your take away would be just half of that equity.  And while the 35% property may be less valuable, if you bought it first, it may actually have more equity.   It's the equity that matters here, not the value of the property.  With a mortgage, the bank is more of an owner than you are until you've paid down most of the loan.   You may find that the bank won't agree to a single-owner refinance.  A co-signed mortgage is a lot easier for them to collect, as they can hold either of you responsible for the entire loan.   If you sell the 65% property, then you can pay off any mortgage on that property and use the equity payout from that to buy out your relative on the 35% property.  If you currently have no mortgage, you'd even have cash back.  This is your fewest strings option.   Let's say that you have no mortgage now.  So this mortgage would be the only mortgage on the property.  It's not so much, as 15:65 is 3:13 or 18.75% of the value of the property.  That's more of a home equity loan than a mortgage.  You should be able to get a good rate.  It might reduce your short term profit, but it should be survivable if you have other income.   If you don't have other income, then seriously consider selling the 65% property and diversifying the payout into something else.  E.g. stocks and bonds.   Perhaps your relative would be willing to float you the loan.  That would save you bank fees and closing costs.  Write up a contract and agree to take assignment of the title at payoff.  You'll need to pay a lawyer to write up the contract (paying a modest amount now to cover the various future possibilities), but that should still be cheaper.   There's a certain amount of trust required on both sides, but this gives you some separation.  And of course it takes your relative out of the day-to-day management entirely.  Perhaps the steady flow of cash would provide what they need.   If your relative is willing to remain that involved, that can work.  Note that they may not want to do this, so don't get too attached to the idea.  Be prepared for a no.  This would be a great option for you, as you pretty much get everything you have now.  They get back the time meeting with you to make decisions, but they also give up control over those decisions.  Some people would not like that tradeoff.   The one time I was involved with a professional managing a property for me, the fee was around 7% of the rent.  If that fits your area, you might reasonably charge 5%.  That gives a discount for family and not being a professional.   There's a relatively easy way to find out what fits your area.  Look around and see what companies offer multiple listings.  Call until you find a couple that will do management for you.  Get quotes for managing your properties.  Now you'll know the amounts.   The big failing though is that this may not describe the issue that your relative has.  If the real problem is that the two of you have different approaches to property management, then making you the only decision maker may be the wrong direction.  This is certainly financially feasible, but it still may not be the right solution for your relationship.   If you get a no on this, I'd recommend moving on to other solutions immediately.  This may simply be too favorable to you. "If you and your parents both put up money to buy a house or anything else, what share each of you owns would be a subject for negotiation and agreement between you. To the best of my knowledge, there is no law that says ""if person X pays the down payment and person Y pays the monthly payments, than X owns 40% and Y owns 60%"" or any other specific numbers. Parents often give their children money to help with a down payment on a house or a car with the understanding that this is a gift and the child still owns 100% of the item. Other times they are unwilling or unable to just give the money and want some stake in exchange. In the case of a house or a car, there's a title that identifies the owner, and legally the owner is the person or people named on the title. I'd suggest that if you want to have split ownership, like if your parents are saying that they'll help with the down payment but they want to get that money back when you sell or some such, that you come up with a written agreement saying who owns what percentage and you both sign it. If there was a dispute -- if you never had an agreement about what share each owned and now you're selling the house and you're arguing over how much of the money each of you should get, or your parents want you to sell the house so they can get their money back but you don't want to sell, or whatever -- ultimately a court would decide. Presumably the judge would consider how much you had each paid in, but he might also consider who's been paying property taxes, how much work each has done to maintain the place, etc. It's better to have a written and signed agreement, something that everyone involved is satisfied with and where you all know exactly what you're agreeing to, rather than having a nasty surprise when a judge says no, you're not getting what you were assuming you were getting." "There is a term for this. If you google ""House Hacking"" you will get lots of articles and advice.  Some of it will pertain to multifamily properties but a good amount should be owner occupied and renting bedrooms. I would play with a mortgage calculator like Whats My Payment.  Include Principle, interest, taxes and insurance see how much it will cost.  At 110k your monthly fixed payments will depend on a number of factors (down payment, interest, real estate tax rate and insurance cost) but $700-$1000 would be a decent guess in my area.  Going off that with two roommates willing to pay $500 a month you would have no living expenses except any maintenance or utilities.  With your income I would expect you could make the payment alone if needed (and it may be needed) so it seems fairly low risk from my perspective. You need somewhere to live you are used to roommates and you can pay the entire cost yourself in a worst case. Some more things to consider.. Insurance will be more expensive, you want to ensure you as the landlord you are covered if anything happens.  If a tenant burns down your house or trips and falls and decides to sue you insurance will protect you.   Capital Expenses (CapEx) replacing things as they wear out. On a home the roof, siding, flooring and all mechanicals(furnace, water heater, etc.) have a lifespan and will need to be replaced.  On rental properties a portion of rent should be set aside to replace these things in the future.  If a roof lasts 20yrs,costs $8,000 and your roof is 10years old you should be setting aside $70 a month so in the  future when this know expense comes up it is not a hardship. Taxes Yes there is a special way to report income from an arrangement like this.  You will fill out a Schedule E form in addition to your regular tax documents. You will also be able to write off a percent of housing expenses and depreciation on the home.  I have been told it is not a simple tax situation and to consult a CPA that specializes in real estate." In effect, you are paying for 70% of the house but he gets half the gain. On the flip side, you're living there, so that probably makes up this difference.  It will be toughest if the house jumps in value, to the point you might be forced to sell.  You might want to think about that a bit. "This is fine, just have a plan before you go into it. Look up a co-ownership agreement contract off LegalZoom, they are like $15, or get a lawyer if you want. Decide if you want to be ""Joint tenants"" or ""Tenants in common"". You probably want to be joint tenants so that if one of you dies the property goes to the other person. Go through the agreement, make any changes you want, and then both sign it. These documents outline what happens if someone dies, or if you break up, or if you are allowed to sell your ownership, and anything else. Keep a record of who has paid what % of equity towards the house. Also look into tax laws, if the mortgage or house is only truly in 1 person's name they may get a tax break that the other person will not get. The co-ownership agreement is essentially the same agreement that happens when you're married, the only difference is that it happens automatically and implicitly when you're married. It's interesting that some people are saying this is a horrible idea when it's practically the same as the agreement you'd have if you were married. Whether you're single or married, if you own a house with another person and you break up, it's going to be a bit complicated. Get a contract in place beforehand so that things go as smoothly as possible. If you are both rational adults you shouldn't have any problems." "I just wanted to give you a different perspective, as I own a house (purchased with a mortgage), with my girlfriend. I think it can be done safely and fairly, but you do need to involve legal help to do it right. There really is nothing to be terrified about, the extra cost to set this up was almost irrelevant in the bigger picture of legal costs around purchasing and the documents describing the ownership scheme are quite straightforward. Maybe it's a UK thing, but it seems rather commonplace here.  We've chosen to hold this as ""tenants in common"" and use a trust deed for this when we purchased. We had a solicitor write the trust deed and it clearly states what percentage of the house is owned by either party and exactly what the steps would be taken, should we decide to end the trust (e.g. in case of a split-up). This includes things like the right to buy out the other person before selling on the market etc.  We also had to make wills separately to indicate what should happen with our percentage of the property in case one of us died as with this type of ownership it doesn't automatically go to the other person.  Finally we're both on the mortgage, which I guess is the main difference versus your situation. But again, you could get legal advice as to how this should best be handled." Also, does anyone know of any books on doing this sort of thing, i.e. renting out half of your home to a tenant and living in the ret? Head down to your local library. Mine has a state guide for renters and another one for landlords. There will likely be a lot of Nolo Press books around there too.  You can also research the property tax on a lot; many counties run an arcGIS server that will tell you who owns a given property, what the assessed value is and the total tax bill, etc. It may be possible to get more cash than you currently have. For example, If you have $200,000, you could buy a distressed property for $150,000, spend $50,000 on renovations, get it appraised for $300,000 and then cash out refi $240,000 (keeping 20% equity to avoid MIPs) to invest. This would be analogous to flipping a house for yourself. Normally flippers buy a house for cheap, then sell it to someone else for way more than their total outlay in purchase + improvements. The only difference here is there's no 3rd party - you stay in the house and essentially buy it from yourself with the mortgage. I think you wrong about this. There are two problems I see with your example.  * When you created something which costs $150 you have increased the amount of money in the world from $200 to $450 because money is the storage of value.  * After the first transaction you have said that you have $250, which presumably means the money in the bank. However, at a later point when you go to the bank demanding $500 you only consider physical notes to be money. The bank at this point could give you a check book and if you wanted to spend it would simple credit the other person $500 and remove that amount from your account. In addition, the bank could always repossess the items you have sold to the other person and give them to you in lieu of physical money.