Backyard cottage / Tiny Home - first steps? (construction + util)

[Kyrstin Szewczyk]

My husband and I have a large backyard and have thought about building a legal ADU to rent out (or even live in while renting our main house, though that's less likely).

We have comfortable in buying single family homes, hiring for remodel, and managing rental properties. I have also read a book on building tiny homes (which obviously is more complex than cottages due to weight / dimension restrictions but something we are considering due to potentially re-platting later if we can buy another property next to us)

We've never built anything for scratch or ran utilities out and currently have to contend with only having a shared driveway (it's technically half on our property but goes into our neighbors backyard so they've been the ones to use it for years; there is no official easement but from what we looked up from their years of use it's kind of possession being 9/10ths of the law)

Do you have experience building a backyard cottage / tiny home in Seattle? If so, where did you start? Who do you hire? 

Any tips on running utilities to your backyard?

Any idea of cost estimate in Seattle? For the cottage / tiny home and/or the utilities?

How would you fund this project? (we have an idea for a partnership and have been saving cash so may not even need one so I think we have a solution but always am open to ideas)

Any idea on a timeline once the contractor begins work? 

Any tips on working with a neighbor with a shared driveway and construction?