The best contractors will either not require payment, at all, until completion, or will have specific milestones with dollar amounts.  

but it has been awesome to watch you reach new milestones in both your business and investment goals you really are a great example of what you can accomplish in this industry if you are willing to put the time & work in.Here is to the next 4 years of your journey, I'm sure they will be even greater than the last. 

As I look to purchase my first property, my fear and nerves are constantly keeping me from obtaining this milestone..with my biggest fear being estimating rehab costs initially.

I always write my own contract or make sure I can modify their existing contract to include things like: when the job should start, how long it will take, what penalty there is for the contract if they go past the deadline, what approvals need to happen if the job is going over budget, how much I need to put down to begin (i don't like doing more than 30%) and what the payment schedule is after that (some larger jobs will have milestones where another 30% is payed when completed), and what will be delivered to me before final payment (final approval, lien wavier etc..)

I currently put contingencies on the following milestones:Contingencies (able to achieve the following milestones)Site PlanningBase MapSite Plan (End of 2021)Conceptual Site Plan (Beginning 2022)ArchitectureFeasibility Design (End of 2021)Conceptual Design (March 2022)Entitlements & PermitsPre-Application (Beginning 2022)Application (mid-late 2022)**Buyer Submits Refundable DepositBuilding Permit and Inspections (End of 2022)Final Approval to Build for purposes of a banquet hall (End of 2022)**Funding Land Acquisition General ContractorSite and Civil Work (End of 2022)Certificate of Occupancy (Late 2023)Is this the correct approach or is there a better way to structure this offer to take on the least amount of risk?

Otherwise, people can easily become discouraged if they don't meet that "milestone" in 5 years.Debt is a tool that is very useful and very powerful when used properly, but can be a very real game-ender when utilized foolishly. 

Cheers to making your dreams come true and hitting another major milestone 🥂 🍻

I would give him the $100k then as his time is money as well, HOWEVER, for that amount I would expect him to sign some kind of covenant that reduces his equity at certain tiers if he does not complete the project within a certain time frame or hit certain agreed upon milestones.  

I would recommend giving bonuses as milestones are completed by a certain date instead of one large bonus at the end.

Then payout when certain milestones are met (ie. 100% complete on rooms or line items, not perceived progress).