Essentially, this comes down to how strong your credit score is before applying for a HELOC and other measurements the lender will assess for pre-approval.

If you were only measuring on principal pay down I guess you’re guaranteed to hold for about 7-8 years before you sell.

Should all energy efficiency measures be a choice? 

L&I isn't measuring building heights.

GC quoted ~$1200 in labor, so we've saved ~$1k on window and install costs but I've had to source and pick up the windows as well as help my day labor measure them all.

At the small multi family level (2-4 units), comps are a more reliable measure of value.  

Rents are not as high as the sale price in proportionate measure.

The guide should help you measure that.

What are some of the measures i can take to ensure it does not get worse.I am just scared that some day the house will just fall off.Please advice if i should sell the property or what measures i cant take for this.

Whether they list a property incorrectly, don't know how to fill the forms out, over price it, don't ant to actually measure the actual sq footage, don't understand how investors buy (for properties that don't qualify for a residential loan), skip bed/baths in an illegal unit, don't have enough experience to understand market rents/value ect ect ect.