I worked at a place where non-technical management didn't like hearing things had to be refactored occasionally. So the technical managers became very good at i

I worked at a place where non-technical management didn't like hearing things had to be refactored occasionally. So the technical managers became very good at including refactoring of old code in estimates for new (related) features. This generally worked, except when a lot of refactoring was needed. Occasionally, we would learn after the fact that one of our designs, programs, etc. was fundamentally flawed in some way, but we couldn't fix it with a series of moderate changes. Those cases really need a dedicated refactoring effort.