Steven, the answer is very simple: Norm planned out all he built, and created dimensional plans for each project. These were later sold to those wishing to build the project. As I recall, the adironback chairs he made were considered classics, and the plans are still in demand.
Not being a regular viewer the one thing that does stick in my mind was from a conversation with someone who was a regular viewer. They said that Norm always made three of any project for his program to show different stages of the process.
On another home shop program this concept was spotted when during the steps of the project there was a definite change in the grain pattern of a surface.
The convenience of editing video sadly doesn't work in the shop.
My latest project didn't have a single thing committed to paper or computer screen. It was kind of funny at one point how it came about realizing there needed to be a couple more pieces to be cut.
It is a spool for salvaging a few hundred feet of barbed wire from fences where a field is being rearranged.
jtk
"A pessimist sees the difficulty in every opportunity; an optimist sees the opportunity in every difficulty."
- Sir Winston Churchill (1874-1965)