I have 2 options:- finance the construction pre-selling the apt, and take my profits (expected to be around 700K pre-tax); or- finance the construction with a 6-7%/year loan (collateral = my house), keep the 10 units, and once the building is completed in 24 months, rent them for circa 180K/ year gross.

Recommend you first figure out the property Class you want to invest in, THEN figure out the corresponding location to invest in.Property Class will typically dictate the Class of tenant you get, which greatly IMPACTS rental income stability and property maintenance/damage by tenants.If you apply Class A assumptions to a Class B or C purchase, your expectations won’t be met and it may be a financial disaster.If you buy/renovate a property in Class D area to Class A standards, what quality of tenant will you get?

In a business, I’d say owner “net profits” (exclusive of any owner salary) of $200,000- $1 million.  

The one downside is the ratio between salaries and the housing market.

., deductions, 1031 exchanges), could potentially outweigh your current W-2 salary over time.Suggest a trial period for the first deal, involving him in decisions to build trust and confidence in the process.

Quote from @Kody Smith: without getting too deep into my finances, what my strategy is...1. take loans to buy properties (leverage)2. fix/flip for day to day cash flow income3. use some of the fix/flip income to buy consistent cash flow through:- business acquisition, - commercial properties (MF and store fronts),I have no intention of doing ALL of the management myself, I will hire management as needed (medium term goal)my expected core role is money provider, evaluating the numbers, making decisions, and connecting with investors, wholesalers, lenders, contractors, and property owners.while I am just on step 2 of the journey, I am looking toward step 3 to stabilize, and not worry about if house prices drop mid project or not (or not worry as much) So to be fair this is more about obtaining and growing a real estate business not simply buying rentals for cashflow.

Rented in Feb 2024, Lower cash flow than expected.

Contractors, unless you have a working relationship with them, normally do not want you bouncing ideas off them.Understand what their hourly rate is, have a discussion with them that you are okay with paying them an hourly rate if they walk the property with you and provide you a scope of work along with an explanation of what you can/can't get away with in regards to improvements.ask them if you go with them, if they can credit you the amount that you paid.Once you develop a working relationship with a few contractors, you can bounce ideas off them and expect quality responses.I do not invest in New York.Best of luck. 

Set real expectations with your owner. 3.

Ultimately, clear communication and expectations handled in a respectful manner can avert any issue.