Wow some interesting replies here.
Don’t do it. Employ professional’s!
Scaffolding will cost around 350 quid and you will save a couple of days working by being able to access things properly.
Cherry picker hire, around 200 plus vat for training alone and don’t even think about using one without it.
Aluminium towers, fairly cheap to rent usually by the day etc. But very easy to get wrong in use and not suited for what you need. It wontbe stable enough to run a ladder against and work safely.
Your comment “Could keep all tools needed and cement mix on tower and then use cat ladders to get up to stack to work with a harness” suggests you are well out of your depth so really ought to employ someone else and use the days you save to earn cash to cover the bill.
Oh and don’t even think about using a harness unless you are trained and have a rescue plan in place.
https://www.google.co.uk/search?hl=en&site=imghp&tbm=isch&source=hp&biw=1223&bih=596&q=safety+harness+injury&oq=harness+inj&gs_l=img.1.1.0j0i5l4j0i24l3.878.3541.0.6759.11.10.0.1.1.0.128.984.7j3.10.0.msedr…0…1ac.1.58.img..0.11.989.YWHnuVY-W34
You might think this is scaremongering but serious things happen at height.