I am planning either a 3-story 27 unit apartment building OR if I can purchase the combined 0.8ac parcels on each side of me, construct a gated condo community with end to end road access.

This MFH property is 50+ years old and the City wants to enforce recent building codes on this property.

This book got me off the sidelines and in the game: Build a Rental Property Empire by Mark Ferguson and this book elevated my landlording methods: Managing Rental Properties by Heather & Brandon Turner~ Lindsey

House hacking can be a powerful strategy to build wealth and financial independence. 

There's a lot of large apartment building going on but I'm concerned that there may be too much building given the number of jobs in the area.  

IMO your safety from an investor standpoint comes with building a large portfolio.If you can keep it "under the same roof" even better.Less people to speak with and less drama with logistics and correspondence.The bigger the portfolio, the safer and the better ROI will be long term.Our most unsatisfied investors are the one's that own 1-2 properties and get pissed off with me and my company if they go vacant.Unfortunately, turnkey providers aren't magicians or God and can't wave a magic wand and turn 2 properties into 10 over night lolFolks that own 7-8 or 10+ properties with us aren't bothered if 1 or 2 are vacant, as the others are still performing and cover any losses on those that aren't.Thanks and much success

Then I work out an estimated rest of life (the building inspector did this as part of his report) and then I put in an estimated replacement cost. 

I look forward to connecting and growing relationships with hungry like-minded agents/investors that can give wisdom.

Not just residential, so it would expand the possibility of ADU construction to alot of building owners.

This strategy acts as a low barrier to entry to allow someone with little capital to enter the investing world, to build equity, and repeat the process to continue to build their portfolio/wealth.I would be happy to go into more detail should you ever want.