Building houses is an excellent example. When a large corporation is building an estate, the time and cost taken to build the houses is fairly well known, and c

Building houses is an excellent example. When a large corporation is building an estate, the time and cost taken to build the houses is fairly well known, and consistently accurate (to a degree). Custom/self builds are famously hard to predict, and nearly always go massively over budget and over time (twice as long, twice as much is more common than on budget, on schedule). Often because there are significant changes to the requirements as the project goes on, because the customer changes their mind, or because unexpected things are discovered during the build. In fact, with the arguable exception of teaching, which is a classic example of deliver to deadline with no specific set of features, all of your examples are things that people are unable to accurately predict.