What if my suitable alternative is to free-climb upto windows, and clean 'em. Surely then, after considering free-climbing, finding it not suitable, I could then use ladders?
Er..... maybe free climbing isn't a recommended method to clean windows at height. What I meant was that in with your window cleaning equipment, you must have an extendable pole, on which you can put a mop/squeeegieeee, that is capable of reaching the windows you intend to clean using a ladder. Before you use the ladder, you must consider the alternative option you have. If you then decide the best option for the job is using a ladder, the that is in compliance with the WAHL.
If you don't have an extendable pole, or any alternative method of cleaning the windows, then you cannot have considered an alternative first so you are in breach of the WAHL.
Also, the ladder (or you) must have at least one method to stabilise and/or make the ladder 'safer'. So anyone who uses a ladder without rubber bits on the bottom is also breaking the law unless they have someone footing the ladder.