We pick material, finishings... make the house flow (people like open concept now so we move walls where we can, etc). 

We have a few from overseas that have a tax requirement of showing material costs on larger items (furnace, hot water tank, windows, roof etc) so we send them material receipts.  

If you are considering an prefab ADU, take a look at the prefab options with Back Porch Homes, they are prefab stick built homes and all materials used can be replaced/repaired with products you can find at your favorite hardware store instead of specialty stores like more manufactured homes.

You arent taking into consideration rising lumber and materials costs , contractors are busy and wont get to your job for a month or two .

It is driven by the market you are in.

I can come back in person for only a few weeks out of the year (gotta stay tax exempt), so basically one big trip home each year or so.I've got some good reading material for tonight, and hopefully I can find a few hours of stable connection tomorrow as well. 

I do not possess the creativity when it comes to home design to decide how I want the kitchen or bathroom to look and what materials I want to use.

The doors are about $1,500 and $125 labor and materials per door.

@Nancy Roth,with granite you care about this:-material cost-installer cost-solid cabinets under (also leveled!!!)

Luckily, we operate our own management company and have been compiling an extensive packet of materials to share with investors.