I've seen it said that in any ongoing work on a large and complex software product, about 20% of the time is spent on upkeep just to keep the system from degrading further. Probably your team was already spending a portion of their time shoring up the worst parts. That's typical, and why the build up of problems slows down feature work.
I always plan on spending some percent of my time on work I know I'll have to do before I can start adding the new features. Regardless of how I'm asked to estimate, I keep in mind the cleanup work in accounting for the total effort.
Unfortunately there are still a lot of PMs and folks, including some programmers, who aren't aware of or don't understand the need for structural maintenance. Those are the teams I regularly see start out going very fast but within a few months get bogged down in having to work in the awful system they built.
I always plan on spending some percent of my time on work I know I'll have to do before I can start adding the new features. Regardless of how I'm asked to estimate, I keep in mind the cleanup work in accounting for the total effort.
Unfortunately there are still a lot of PMs and folks, including some programmers, who aren't aware of or don't understand the need for structural maintenance. Those are the teams I regularly see start out going very fast but within a few months get bogged down in having to work in the awful system they built.