Should connect with an engineer that would work with the city 

We have found that cost seg engineering firms can also be helpful in answering some of these questions.  

The cost starts with  1.) plan cost (survey, civil engineer, site plan, architect, structural engineer, mechanical/electrical/plumbing (short for MEP) plans, etc.).

Hi All, I am a structural engineer by day looking to branch out into the world of real estate investing.

I would definitely have a structural engineer do an inspection if moving forward, but the question is...should I?

After posting I saw in your profile you are a software engineer.....What would be REALLY cool...If you could develop an easy to use Gantt chart software (Think Microsoft Project, but WAY easier to use) that was designed specifically for Real Estate reno / BRRRR. 

B.S in Civil Engineering, I night my first house and started flipping.

An additional benefit of a detailed engineering-based Cost Segregation Study is that it can increase potential insurance premium savings as well as provides support for the property tax appeals process.

Knowing what I don't know I hired a reputable civil engineering firm to handle my site plan.

Bridge financing(interest only):For construction loans, you could do a bridge solution to help you buy the land and do the vertical construction(get the land surface engineered and developed for putting up the apartment buildings) and then horizontal- downpayment will vary.