None of these are probably easy or simple solutions and plenty of hoops, but there are options.House back here in DFW is pretty tough with a duplex and probably works best with 4-5 bedroom if you can qualify for that and then rent bedrooms. 

If you BRRR and try and refi all of the equity out you'll just have a high mortgage that makes it tough to cash flow.

Get estimates only for labor and buy ALL the materials myself ?

Quote from @Deven Ziertman: Finding a HELOC for a self-employed borrower without full income verification can be tough, but there are a few options:✅ Equity-Based HELOCs – Some lenders offer HELOCs based primarily on equity, rather than strict income ratios.✅ Private Lending Alternatives – If traditional HELOCs aren’t working due to income constraints, a short-term private loan could serve as a bridge solution.✅ Cash-Out Refinance vs.

REPS = Your rentals are non-passive if you materially participate in them.

You will need to have some "float" money in your account to cover paying your general contractor or paying for materials while you wait for draws to be reimbursed.Once you get really experienced you can get into a groove where the GC does the work, asks for $, then you ask your lender, then as soon as your lender funds you can pay your GC.

You can get paid for the materials, but usually not your personal labor.....

Of course these are also just general rules, construction costs will vary greatly dependent on site conditions and design.Most material costs, insurance costs, permitting, licenisng etc. don't deviate greatly depending on where exactly in the city you build and unfourtnately, most of the in-fill opportunties are in the neighborhoods that can't achieve the required pricing to make the cost of new construction pencil.

I would like to keep expanding, but market conditions are tough for buy and hold LTRs. 

One of the biggest factors at play is the ongoing tariff war, which has driven up the cost of building materials, making new construction more expensive.