I got parts of it from somewhere and modified it. I think it might have originated on drawings by Kimberly Seldon (Business of Design) I saw in a class and zoomed in on.
What price point are you looking to pay? I use someone to draw my plans that I think is $60/ hr, but I do the field measure myself. I bring my assistant with me which makes drawing and measuring rooms much more efficient. Happy to share his info if you’re interested. I’m sure there are cheaper people out there, but I’m pretty picky about the quality and consistency of my drawings and have had bad luck in the past even with reputable teams that delivered inconisistent results. So I’m willing to pay for less headaches and micromanaging.