[rick32]

My sister-in-law wants to refinish her attic into office space. If we insulate everything do we still need to install vents?

 

[Just Bill]

I assume you have already researched proper floor joist sizes needed to convert that into a living space, as well as emergency egress??? That said, yes, you should have a good path of flow through ventilation under the roof deck, soffit to ridge ventilation works well.