I clean loads of these 3 story Bovis homes. you can reach all the windows easily with a 25ft pole but i have the two extension sections on my Gardiner, to get the velux on the rears, an extended goose neck would help as well to clear the gutters and you are well into the garden to get access.
Something else to watch with these houses, they use two types of window on them, the ones with the proud Georgion frets are much more time consuming and awkward than those with internal frets.