@Emil Pinlac - we're based on the Bay Area so prices may be a bit lower in Sacramento but we've done a few projects in a similar price range as @Whitney Hill mentions - $150-200K of project costs for ADUs ranging from 500-750 sq ft.

I can listen to books and educate myself on whatever I want while at the gym, in the car, etc.A couple I'd recommend to you based on your post are..FLIP - How to Find, Fix, and Sell Houses for ProfitThe Book on Flipping Houses How to Buy, Rehab, and Resell Residential PropertiesThis book is not currently available on Audible but a must readThe Book on Estimating Rehab Costs - J ScottBigger Pockets has become one of my best resources.

@Mason Myers Pricing will vary quite a bit, based on several factors.

I personally have never had any architect or structural engineer bid any of my projects or that of my clients based on a percentage of the construction, it is always based on time which is subject to complexity.

And, while that's out of their control, modeling a conservative base case that assumes the same exit cap, or a few points higher can make all the difference. 

Hello Bigger Pockets community.Trying to get base line number of what the average % yearly operating expense per unit is for a typical class C property, 2-3 BR on a 5 to 20 unit property.

Quote from @Joshua Posada: Im open to other areas.What do you have in mindI'm based out of the Pittsburgh area would you consider Pittsburgh? 

Otherwise, you have a penalty fee AND interest due from when the qtr'ly payments should have been made.So, in your case it might an incentive to get your return prepared and file as soon as possible to limit any late fee interest due.For those working a job with uneven payments, e.g. sales where commissions could be anywhere throughout the year, there is a part of the form (I think Annual Installments.. it was "AI") where you can try to show that you paid qtr'ly as your income came in. 

So, thats a fair amount of equity that you are pricing yourself out of due to not wanting to pay ~6% of your gain (federally anyway).Probably not as sophisticated as the Deferred Sales Trust, but an installment sale would spreadout the liabiilyt and maybe you could be federally taxed at 15% instead of 20%, thus saving 5%. 

Looking to refi based on the value after rehab based on rental income/cashflow (expecting it to be around $200-210k value) Aiming for $150k loan for paying off current mortgage and covering remodel/rehab costs on my propertyIs this doable without a significant down payment?