I had a call from the one below today. The last people took 5 working days. 2 men 2 1/2 days. and charged £500. You have to wonder why they didn't go back this year. When I said £800 (the last people did it on ladders) they were staggered. 
http://www.berkshirehistory.com/castles/barton_court_kintbury.html
Doesn't look that big. Looks like doing 3 semis
Never known 3 semis take 5 days. In fairness that is only the front and you need to walk around it to appreciate the scale.