Bell Road Office Park › Guides › What NNN means
What does NNN mean on an office lease?
What it looks like on a real suite
Take Suite 100B in this building: 726 square feet at $17 per SF. That is $12,342 a year, or about $1,029 a month. That is the base. Your NNN share is billed on top, usually as a monthly estimate that gets reconciled once a year against what the building actually spent.
The number you want before signing anything is the current operating expense estimate per square foot. Any broker should hand that over without hesitating. If someone quotes you a rate and gets vague about the NNN figure, that is worth noticing.

Quick questions
No, and this is the most common mix-up. Gross rent bundles operating costs into one number. NNN separates them, so the quoted rate looks lower while your actual cost is higher.
Yes. It is usually estimated monthly and reconciled annually against actual building expenses, so it can move year to year.
Ask for the current operating expense estimate per square foot, and ask how it has moved over the last two or three years.