Cleaned a four storey office block. Lots and lots of windows, every one has secondary double glazing. What a pain.
Thought I would share some advice for those doing similar jobs for the first time-
1. Price carefully, it will take longer than you thought.
2. Take at least one million towels/cloths.
3. Take several types of ladders and small steps when doing the insides.
4. Do outsides first.
5. Start v early so you can get some done before the employees arrive.