Don’t worry, however, this is adjusted accordingly with comps (similar 2000sf GLA properties with a 1000sf basement are better than 3000sf GLA properties with no basement, for example).If the appraiser did get it that wrong, then you do have some options...

A blanket mortgage as@Wayne BrooksMentioned is going to limit you and the rates will most likely be higher and adjustable or have a balloon payment. 

For example windshield wiper blades.

Two of the common areas of concern for HELOCs I see out there is the 10 year maturity date and the adjustable rate.

When selling stocks it’s possible adjust whether selling older or newer shares (first in-last out or first in-first out) so one can effectively choose to sell shares that have more or less capital gain associated.

Adjust your criteria to something a little less main stream/common.

The important thing is that you evaluate your goals for what you want your real estate to do for you, and then adjust your criteria and approach to align with those goals.

I would only refi when the rate differential made sense, to avoid an unfavorable rate adjustment, or to remove PMI (like with a FHA loan).

In a slower market (or a downturn in my own market), this strategy might need to be adjusted to allow more time for filling vacancies. 

Invested mainly in Israel (where I live) and a few years ago, started investing in the US in the DFW area.Investing now both in rentals and flips and trying to apply what I knew from the previous experience to the ecosystem in the US with the relevant adjustments (you'll be surprised how many similar elements exist :) )Now expanding in the US to the Augusta, GA with the same mode of operations - finding below market properties, deciding on the best strategy for each one, buying alone or with partners.A pleasure to be here and learn so much from this great place.