In article ,
none none wrote:
Just out of interest for those in the know: what should I budget for
annual up keep (average)?

Zero - other than the usual removal of leaves etc and checking guttering
or any other drainage. If it's well constructed, budget for felt
replacement about every 20 years. If it's done before it's needed it's
cheaper than leaving it until it leaks.

--
*Virtual reality is its own reward *

Dave Plowman London SW 12
RIP Acorn