Looking for guidance building an ADU from scratch!

[Marc Estepa]

Hello BP fam! So, I'm looking at a potential property and trying to figure out creative ways to househack and add value. Anyway, there is a home I just put an offer on that has a pretty significant sized backyard. I am toying with the idea of building a Detached ADU in the area. I'm thinking a 2 bedroom/2 bath type Apartment. The neighborhood has an HOA, so I'm about 80% sure they'll have a problem with it. After reviewing the covenants to their HOA, I see that it needs to be approved with a 2/3 vote and I need to have all plans drawn out to present it to the HOA for approval.

When taking on this project, where do I even begin? What should I estimate as roundabout costs for such a project? The home has city water and power and not in a rural location. How can I draw up plans without spending a ton of money? Before breaking ground, I need to be able to present as much of the detail to the plans as possible.

Thanks in advance!