We bought two of them during the pandemic! One is my office and the other is my wife’s music studio; they’re about 12’x16’ each, with a storage loft above the door. The company we bought them from in NC has a website that lets you design the layout, add windows, etc., and then you can have it unfinished (for a workshop) or finished with insulation and electrical. They construct them offsite and then deliver them to your property—all told they’re on the order of $10-15k each depending on options chosen, and then you’ll need to arrange a gravel pad for them, electrical hookups, etc. Not bad, especially financed, and cheaper than an addition on the house. :)

Did they ship them from NC to a different place? Or is the vendor local to you?

I remember seeing a few of these during the pandemic and the idea of a private separate office is appealing.

They build them in NC and we live there, so they literally drove them over to us on a truck and deposited them in our yard. I'm not sure what their shipping range is, but given that they're just driving it, I would imagine they could truck it just about anywhere in the contiguous US with enough financial incentive. :)

I believe the official term is accessory dwelling unit. You'll have to check your local zoning regulations on the rules and regulations for those. Yes there are companies that specialize in building those.

ADUs generally have plumbing/electrical and are permanent living spaces. You could get away with an accessory building (permit required) or depending on your zoning, a smaller structure/shed (no permit required).

There are MUJI locations in Boston, NY, and Portland. https://www.muji.us/pages/store-information

Tuff shed will give you a basic structure on the cheap and are very customizable. They’ll come onsite and build it. Hire a contractor to finish the interior as you like.

I had a 16’x12’ built for around 6k (pre-pandemic) that I use for an office.