Planning install of prefab 10x16, have choice of doors/windows/etc.

Amazing variety of choices, currently considering
1) 6' barn-door for easy loads/unloads. Has primitive lock system could be upgraded somehow;

2) no man door needed;

3) some windows desirable, such as 3/0x1/0 slider opening to limit unauthorized incursions/snooping; probably one on each side at 5' eye level.

4) probably some degree of insulation. Spray foam installers estimate ~1200 for R13 equivalent in vaulted barn roof & walls.

Inevitable man cave conversion potential.

I'd sure install a personnel door. That will allow you to latch/lock the "barn doors" from inside, which offers a whole lot better security. And 10x16 isn't very big.

good point on the lock, will have to explore further options;

appreciate the ideas