Sounds like your already balls deep into this.
I hope you considered that it will take anywhere between 2-4 years to fill all 100 offices, and that most opperations of that scale, have 5-6 office empty at any time during renovations.
Also, you should vary the size of each office, and make avaiable for expantion into other units- Ie, when your first tenants move in, spread em out, so that if they grow they can grab the office next to the one they already rent.
Shit- I'm going back into property management mode...there was a reason I quit that job
Good luck