A broom may scratch the glass. We found a long-handled squeegee mop-like contraption which has a jointed handle - it just reaches if we stand on a small stepladder. Then we hose off the soapy water. However, it was one of those one-off offers from Lidl.
I am sure there will be something similar in a hardware shop or on Amazon/ebay etc.
It is one of those once-every-so-often jobs which are difficult but worth it.
The window cleaner will do the windows but not the roof.
Here is a similar one, other places may offer something similar:
www.amazon.co.uk/garden/dp/B000K4X7BK
Trump has only been in office 4 days
