So they want a estimate huh

Any ideas, 9 stories up,with a 24" ledge to walk on

Drop work (RDS). 24" overhang isn’t too bad. How is the roof setup?

entire building? or just the 9th floor… if its the entire building how bout a lift?

flat roof, yes the entire bldg,and downtown…lotta permits to get a street closed off around here

You are hanging to each horizontal over hang. Just jumping off, mid air transferring to each safety rope & cleaning the whole wall instead of doing 2 window drops.
just seams the fastest possible way without a lift.

I’d do it with a wfp if I had one
3 to 5 safety lines droped the wfp on the roof
Wear a y lanyard with two safety shackles to safely transfer to each safety line. I’d also tie the wfp off to myself
Would leave my chair at each level @ the end of the overhang