This other question is similar, but was referring to a specific renovation/repair (new flooring) that, while expensive ($1500), isn't very expensive – it's feasible to consider saving up for over a short period of time.
So, I'm curious: Imagine one wanted to do a major home renovation such as: building an addition to the home, finishing the entire basement (assume with bathroom), or redoing the entire kitchen.
In those cases, would it still make sense to save up the cash, or else take out a specific loan, additional mortgage, or borrow from a line of credit? Actually saving up the cash for a major renovation like that – easily exceeding five figures, perhaps approaching six! – could take many years, decades!, for some families.
So, if one could really use the additional space and didn't have cash on hand, would borrowing for such a renovation be considered "good" debt similar to a mortgage? Or are there still reasons to save up the cash?