Do you have an iPhone or any phone with lidar built in? It’s been a while but I recall it being an option for scanning, make use of tools you already have. I’m not sure what exists for Foss related apps though sorry, and afaik they’re not super accurate (dedicated scanners can get <0.01mm resolution from what I’ve seen but they’re expensive) but if your goal is layout that’d do the trick in my view. Heck, as you said, camera scanning would work, there’ll be cleanup but should be good enough to get you dimensions.

Another thought, could check with local makerspaces or the like, totally possible they may have scanners you could use, or could put you on the right track. Diy wise, kinects as mentioned, I’m not experienced with these but there are photogrammetry tools, micmac could work, there’s meshroom but that needs some compute hardware and COLMAP could also be worth looking into