Think Twice and a agein before doing this again. Save everyone the headache in advance.
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16 yrs real estate

If you figure out how much it would have cost to have the property maintained by someone else, you can put a dollar figure on the maintenance, improvements, and property management. That’s usually about 10-15% of the fair market rent value each year. If you had rent of $1,000 for 3 years, 10% of that figure would be $3,600-$5,400, depending on the amount of work it took to take care of the place. If you had it for a long time, this can add up to a lot of money.

Whatever you figure the value of the maintenance and other work was, #1 should get 85% of that and #3 should get 15% of that figure. Remember to adjust this if #1 was paying less rent than an outsider would have paid, because that would mean they already benefited while living there.

If you take the net profits less the figure you derived for managing and maintaining the property, you get a net number that represents just your investment property gain. This should be split 60% to #1, 30% to #2, and 10% to #3, which is in direct proportion to the dollar investment they had at risk.

The only topics left open are determining how much is a fair reimbursement for the work of maintaining the property and whether or not the rent was fair or needs to be adjusted. You can get both questions answered by any professional real estate management firm in the area.

Good luck!
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Did investor 1 have a reduced rent during the ownership period?

How was the cashflow from the property divided?

Investor 3 paid 1/10 of the cost, so provided there was compensation for maintenance during the period of ownership, he should get 1/10 of the profit.

Investor 2, 30%.

Investor 1, 60%. if he had bought a home by himself and it had apprciated, he’d be entitled to that appreciation.

Whatever you do, get a lawyer (out of the profits) to draw up the paperwork and have each of you sign the agreement.

Now if there was no compensation for the maintainence and investor 1 paid market level rents during the ownership period, then working in a back pay formula would be useful.

Caluculate an hourly rate for maintainence work. How big was the property? Duplex, 4-, 8-, 60 unit apt building? Find an average number of hours spent on maintainence per week and pay 1 and 3 appropriately. Then you can split the investor profits evenly.
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If you haven’t taken out the maintenance, then you need to deduct the cost of maintenance out of the profit and pay each of the parties back for the maintenance they paid. Keep in mind that investor #1, as a renter, would normally have had to maintain the property but I’m assuming that he did more than just "maintain" the property.
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