I spend longer on first cleans for sure but 80 mins on a bungalow seems slightly excessive....this is where hot water helps a lot....I will charge double on really dirty first cleans....I'll also dry off the top seals/frames on ground floor windows if I think they may cause me problems with a fresh dry scrim(runs/spotting etc)....
I generally clean everything on a first pass; top frame glass sills together.
Then I go back to the start and do the glass again.
Same as these guys. Daz has a point with Hot water, as it does make a huge difference on a first clean, especially if they are really bad.
But, I use the same method, go to town on the frames and vents (which I flush (pending the type of vent) until clear water comes through), then I clean the windows. Once I'm back at the begining, I will state again but miss all the frame work etc so I'm ensuring the glass is clean and streak free.
I will then explain to the customer, that some seals may trap in the dirty water n leak it out later and if this happens, let me know and I will return. Its my 24hr guarantee.
(however, If this is a first clean within the area of my rounds ie, same street, I have been known to double back and check all the glass work to ensure. This has proved me well for two reasons. The first, the customer sees that I offer a great service and I ensure their windows are clean. The second, it reconfirms to me that my technique works and that I do a fantastic job. Yet more nowadays, I just walk round once I'm finished and check the windows whilst they are still wet, you kinda know which water bead types are going to dry not so good and this has served me well, as to date, I've not had one call back