Short term it is difficult to make the numbers work, the cost of new construction and the time it takes to zone-plan-build are usually the main reasons why private investors stay clear.

For this reason it does not matter if the HELOC has a higher rate than the mortgage.

Mainly my sister is the main admin and we hire a facility manager for reach house.

Construction is mainly CMU, Concrete, and Steel (at least for my projects), and there is a bottle neck of those resources as only few supply the area.

It all cash flows like a gold mine until the roof needs to be replaced, the main line goes, or you get your first turnover bill and need to upgrade a kitchen. 

I can totally see why you may have felt ashamed, but the reason these forums exist is to share information.

The six month cd isn’t the point my understanding is that I can’t just take out the HELOC, I need to actually use the money for my plan to work and a short term CD seemed safe and reasonable 

The reason the answer is framed this way is because when you take a HELOC out to make repairs on your personal residence, you are allowed to tax the interest deduction on your Schedule A of your 1040 income tax return.

The laws are off-putting but I don't think that's a real reason not to invest there.

Unfortunately, my work phone is forwarded to my cell phone as I mainly work from home due to health issues.