It seems to me that the greatest risk in a 5 year build out is "obsolete" technology. Not technology is really obsolete (you could totally build a startup on classic ASP or jQuery), but I know as standards change, polyfills are no longer needed, libraries become abandoned, etc, it can be tricky.

On a side note, I wish this was around in 2022. While I see it's designed for apartments, I spent a ridiculous amount of time converting our new house dimensions into a 3d model as we were planning out furniture, etc.