Seeing as you are paying for the install, but buying the pool and associated stuff from the manufacturer, you will have to pay sales tax on that purchase.It's just like if I bought a head gasket kit for my car but paid a mechanic to install it.

@Lawrence Potts Check in with your attorney on the mechanics on execution but I would include a contingency to have the HELOC paid off at closing from his portion of equity.

Literally there are going to be differences from each bank to the next, so you'll likely be poorly served by dealing in broad strokes here.Suffice it to say:  it's common to find lenders who will escrow 12 or more months of interest payments for you at the initial closing, and during the construction phase most construction loans are interest only, so in essence what you're saying could be construed as a norm within the construction industry, but the mechanics will vary.

We went back to the mechanical pushbutton Codelock latch, but it's not as secure as a deadbolt. 

I have been a real estate agent, trim carpenter, server, bicycle mechanic, caregiver, even lyft driver.

the average house I wholesale as a rental needs 20-25k and that includes updating bathroom/kitchen and mechanicals.

It depends on quality of construction, type of mechanical systems, age, and asset class.

I am also open to recommendations if you are kindly willing to share.Plumbing - AAAA Cheapest Plumbing, Aztec Plumbing, Gator Drain, G.P Plumbing & Air, The Plumber's PlumberElectrical - Service Today, Always Affordable Electric, American Mechanical, O.T Electric, Flip the Switch ElectricalHandyman - Reliable Raymond's Home Services, The Hawaiian Handyman, 2 Veterans Handyman Service Thanks for the help!

Their goal is to become an equity partner and we're brainstorming what the mechanics might look like. 

I too am a Program Manager, with a degree in Mechanical Engineering, so you probably have a solid and logical train of thought!