I've known proprietors of a couple very successful window and professional house cleaning businesses. Friend's grandfather started washing windows in NYC (many moons ago - my friend mid 60s/youngest granddaughter) and during career invested his lucrative earnings into Florida real estate (buildings) -- quite the land baron. The maid (residential) expanded her business to commercial cleaning, window cleaning, and landed gov contracts. She's done immensely well.
There's always a shortage of industrious, ethical, window/housekeeping businesses in this city and costs more than double than what paid in so california. Good luck squeezing in w/a reputable, solid, window cleaning company If not on monthly schedule. There's many start ups if you want to roll the dice.