[thinkstoomuch]

To me, technical debt comes in both the intentional and non-intentional form (and more often than not, the latter). In fact, I'm a firm believer that all software tends toward entropy, so feature additions inherently add to technical debt if conscious care and refactoring is not taken.

Technical debt (to me) is measured in "extra time to add the next feature", however in practice this measurement is impossible, as your control is a theoretical application with the debt removed.