Newbie Starting an ADU

[Henrik Moya]

Hi everyone, 

I am a newbie working full time and planning to build an ADU in my primary residence. I work in healthcare and plan for extra cash flow either renting the ADU or doing Air BnB. It can get exhausting working in Healthcare at times and I plan to have the extra cash to have more family time. I am in the planning stages after I got my HELOC funded.

My questions are:

1. I am deciding on an Attached vs Detached. I prefer attached to save most of my backyard. However, an architect advised me to get the property surveyed to see if an attached ADU is feasible or if I can push the fence closer to the side walk but it costs $3000. Is this a normal starting point for anyone building an ADU, to have a survey of the property done? Is that a fair price?

2. How much square per sq ft is the going rate from a contractor for an ADU right now?

3. From start to finish - what is the ballpark cost for an ADU (650-750 sq ft)

Thank you in advance. 

Henrik