It's a long-term learning process, but an interesting and often profitable journey - best of luck to you!

But, the profit margins look to be eye-popping, sometimes on the order of 10X or better.

Partnering with investors to share profits is another avenue to increase capital.

This is a property has been in the family a long time and I'll be holding onto long term as it turns a good profit.

To get things done as quick as possible , charging by the hour cost the contractor money , charging by the push/inch  is the most profitable way to do snow . 

. :)  these are not credit score loans ( I mean I have a credit score) but thats just a formality its all about capital and relationships with your bankers and deposit relationships thats key as well.Yes your relationships with sub contractors will be a huge factor in profitability, both direct and indirect. 

Like @Kyle Mccaw noted there is significant value in goodwill and I imagine you profited nicely over this pleasant long term relationship. 

Most of the homes we built on these lots sold at a profit, but a couple did not, again, because of the reasons above. 

Congratulationswhat you’ve found that both the INVESTMENT side of real estate, and theBUSINESS side are very competitive; therefore profit margins are compressed, so those “home runs” people like to bragg about are actually quite rare.  

To establish a 50-50 ownership in both the property and future profits, you'll need a formal agreement outlining each person's contributions and rights.