No need to reinvent the wheel here!

Do not over think this, do not reinvent the wheel. 

In no way am I trying to reinvent the wheel here, just looking to see what smarter people did to make it roll. :)

As this was a conversion to condo's there are actually 6 electrical meters (1 master) and 5 gas and water meters.At the rear of the property there are also 3 garages and a small storage closet.The asking price was $252k for the 1 bedroom and $149k for each studio; total asking price was $699k. 

If it's a gravity feeder, such as the rear tray of a canon, it matters much less.

I recently completed a detached 2/2 ADU set at the rear of my property which is 135ft deep.

It's currently zoned R1-R3 and has a rear detached garage with two exits, one from the driveway and one from a connected 15' alley.

I remember many years ago, I inspected an R1 lot which had a main house, rear unit with commercial offices above, so I noted all the units on my inspection paperwork.

Whether your building on a barge or a tiny house on wheels, the fact the that base/structure is non-standard will add complexity and cost as well.I don't know Anacortes's rules specifically, but wetlands/shoreline and tiny houses don't mix well in many cities and counties in WA, especially when you throw Airbnb in as well.

Dear BP Mentor,I feel like I am spinning my wheels.