However, after reading about permits in J Scott's "Estimating Rehab Costs" book,  I learned that some jurisdictions don't allow rental property owners to pull their own permits.

It could take you many months to even pull permits and a savvy HML will know this.

While I do flip homes this is one if permitted to have 4 units with 4 bedrooms would be something I would hold on to as an investment.

If you change the size you will be required to get a permit and will need to meet energy codes.  

When we take down building in Chicago, we need an asbestos report to get the demo permit.

I feel like this information should be public record somewhere like building or construction permits.

Now multiply the number if piers by $250. 29x250 = $7,250.Now add $200 for permit & $400 for Engineer's letter (yes, both of these are required by the City). 200+400 = $600Total foundation price = $7,850.

I remodeled the back, and turned the front of the house in to an ADU, currently getting the permit now that the lot size rules changed.I have been renting the front for over a year at $3000/mnth  (1 bed/1 bath) as a furnished rental, no vacancy since listing.In January I moved up to san Mateo to be closer to work and began renting the back out for $5000, furnished, so far no vacancy.Now we are grossing $8,000/mnth about ($7100 after insurance, utilities and an estimate of 5% for maintenance). 

I received a bid for $90k for the whole renovation (not including the cost of permits) and had a miiiinor panic attack.

Is the 1/1 legal/permitted construction ?