I am planning to build a portfolio dashboard for my properties in Excel, and I have a pretty good idea of what I want to see about them individually and combined. 

I am building ground up so any contractors that do framing, plumbing, electrical, roofing, etc.

There is definitely many builders that will build below $550K.

Quote from @Morgan Leiviska: How I would build this database for you would be to connect with people at local meetups that you find.

I'm building in a brand-new subdivision.

After building a portfolio of fully renovated homes I wanted to give this model a chance.

Quote from @Matt McNabb: I'm a solid $400k/yr job in NYC and have $250k to begin investing as my first step into building a portfolio, although I don't have time to be a landlord so I have to account for management fees.  

Quote from @Chase Calhoun: Just wrapped up a build-to-rent project on Wilson Road, and I’m excited to share how it turned out!

I've been building, rehabbing and selling as an agent in the valley since 2012.

Building a portfolio allows you to gain experience, develop systems, develop your own approach to managing properties etc.