Changing it to some other platform without a good reason is what would not be rational. Spreadsheets have their uses and this is one of them.
Low tech solutions are at times very effective, I'm pretty sure if I would have done that design in autocad or some other program that I would have been able to make pretty 3D views and such but it would have taken a whole lot longer and the end result (the house) would have been just the same.
I often used excel to track my code and keep it organized. Part of this is that most of my work was done in excel; the SQL queries were just to get the data workable. But, so many things would change and it was easy to use the concatenate features of excel to change variable names, table names, and stuff like that.
I'm not a professional programmer either, of course. But it worked pretty well and for a one off exercise was a reasonable way to handle tooling. It's pretty lightweight.