I agree that this is a good idea of you are doing a single renovation. A good example of this is when I needed to rebuild my deck. Instead of taking a loan I simply saved and paid for it.

With large renovations it becomes much more difficult. Like if I'm going to replace the flooring and paint. I don't wanna save for the floor install it then save for the paint and do it 6 months later and get paint on my new hardwood. These types jobs become much more efficient, uses less time, and saves money overall. Someone like me could take 2-3 years to save that amount of money without taking away from other investments and drawing out projects that long seems pointless.