The permits trigger the city inspection.

One other possible reason is they didn't get permits and/or ran afoul of some other zoning and it screwed their numbers some how.

My practice is mostly in the area of RE (State Board of Legal Specialization is the only authority that can permit a lawyer to say they "specialize" in an area of law, which requires fees, exams, and a "pretty pretty please".)Attorney fees are based on several factors that have been thoroughly litigated:(1) the time and labor required, the novelty and difficulty of the questions involved, and the skill required to perform the legal service properly; (2) the likelihood that the acceptance of the particular employment will preclude other employment by the lawyer; (3) the fee customarily charged in the locality for similar legal services; (4) the amount involved and the results obtained; (5) the time limitations imposed by the client or by the circumstances; (6) the nature and length of the professional relationship with the client; (7) the experience, reputation, and ability of the lawyer or lawyers performing the services; and (8) whether the fee is fixed or contingent on results obtained or uncertainty of collection before the legal services have been rendered.Like other professionals that are free to set a market rate, we gauge the highest wage that the market will bear. 

However, I am assuming you did not get permits and inspections.

The R5 district permits single-family residential housing, duplexes and townhouses.

Did you have to get permit/have the place inspected?

I contacted some contractors and figured out that the price of building a duplex with 3/2 units (including permits/site prep) plus land would be about the same, 400k. 3/2 units can rent at around $1500 a month per unit...

This took a bit of time and I had to wait for this to be completed before I could apply for the permits. 

What’s the best way to address this and how long should I permit this?

So I go toTurn in my permit application and the lady tells me I must use an electrical and a mechanical(HVAC) contractor to install all of the electrical and HVAC.