Find architects or designers, engineers of all types, general contractor, etc. to design the project, and know how to keep the design where it's functional, cost effective, but has appeal.

Again, I envision five families working together to cost share a property. 

That being said, they are extremely costly and expensive and generally do not make sense for smaller transactions. 

consider the opportunity cost of doing this#1) sell house for cash or to a buyer with their own financing from a bank, etc and you get 315K at time zero, you invest that at historic SP500 8.4% return over last 220 yrs and it grows to $3,541,514.46#2) do owner financing and you get 100k up front that invested at 8.4% grows to $1,250,000, plus you get your payments at $1400 x 360 months or $502k, invested grows to $3,265,000 total including the 1.25 mil aboveso you come out 300k better not doing it and you don't have to service the loan and all the other risksremember banks don't even carry mortgage notes after origination, they dump them onto the US taxpayer via illegal-unconstitutional havens like Fannie/Freddie/HUD, and for last 15 yrs the FED has bought every MBS in the country, which frees up the Banks capital to do it again and make the real money on churning the points and feesplus will next 30 yrs have higher inflation than last 30 yrs?

Look into the cost of this for both partners and all the necessary schedules that will need to be generated . 

Only thing I will add is if you rent by the room, you also have to factor in landscaping costs (mowing the grass) and ideally cleaning of common areas (eg weekly cleaning service).  

You clearly have little knowledge of how to run a business and the costs associated with it.

We are in the process of flipping our primary home and have found costly repairs that are needed, and we simply cannot come up with the needed funds to pull us through when we list in September.

I got the owners to agree to pay for a new water heater for the building (about $4000), and $10,000 of seller paid closing costs.

I've heard Stessa and Buildium for the most part but find it's actually very difficult to use for the average small scale landlord (I have 7 doors)The cost of Buildium I think is way too high for the small scale self managed landlord like myself. 7 units comes to $55/monthAs for Stella, the UI isnt the greatest and probably tailored for more property management companies, and the accounting features are rather lacking for Canadian tax laws.