Have you tried getting any object into SteamVR Home at all yet? I've only done environments back when they were simple .OBJ models, and if my memory is correct 1 unit = 1 meter.

If you already have the workflow up and running, simply export over a cube of a knows size in Blender and use a real life measure tape to check the size of it in VR 😅 I've done this to verify the scaling of the SteamVR background projection 👍

SteamVR Home uses 1 unit = 1 inch. How to set the scale depends on what importing workflow you use.

If you manually export the model into your addon directory, you will have to scale it to inches in Blender:
https://developer.valvesoftware.com/wiki/SteamVR/Environments/Blender_tutorial
https://developer.valvesoftware.com/wiki/SteamVR/Environments/Environment_Tutorial:_Creating_a_Physics_Prop#Importing_the_Model

If you import the mesh from a file outside your addon directory, it will show an import dialog that lets you pick waht scale to convert from:
https://developer.valvesoftware.com/wiki/SteamVR/Environments/Photogrammetry#Creating_an_environment_in_SteamVR_Workshop_Tools

Thank you both for the info! Just double checking, if I scale the model in Blender and import it from outside the addon directory, I can select "Inches to Inches" as an import option and the scale would remain accurate right?

I'll try using a tape measure to measure distances as well, just to make sure the scaling's correct.

Yeah, it should, as long as the Blender exporter isn't set to adjust the scale.