Over the years, we have been very careful to cultivate a network of genuinely skilled tradesfolk on whom we can rely for stuff we can't do ourselves. It's alway concerning when one of them decides to retire and we have to find someone new.
These days we have an additional criteria to the usual stuff about knowing what they're doing, being reliable, etc. They have to be at least 20 years younger than us so that they will outlast us!