[matthewmacleod]

Actually, I really disagree with this view!

Toilet in this analogy cannot be moved, because it was originally decided, that it will be locked and didn’t invest in mobile toilet. Which was reasonable, but highlights lack of vision for the final product.

I don't think the point is that the toilet can't be moved – it's just expensive and disruptive to do so.

Nobody starts building a house without knowing final design.

I would argue the exact opposite – literally _every_ house is built without knowing the final design! Who knows what someone is going to need or want in the future? I'm writing this from a house that was built prior to the existing of indoor plumbing!

[Ensorceled]

> I would argue the exact opposite – literally _every_ house is built without knowing the final design!

The sheer number of houses that have additions, bathroom renos, kitchen renos, walls blown out, basements apartment added, second floors added etc. etc. makes their claim ludicrous on the face of it.

In software we are often taking an existing design and modifying for new requirements. The house analogy is excellent for explaining WHY one thing is easy but another is hard.

[mannykannot]

A while back, I visited a facility that builds prefabricated houses. Using CAD, they can, and do, create large and architecturally complex one-off designs, something that would not be possible without knowing not only the final (as-constructed) design, but the intermediate states as the modules are constructed, moved to the site (including ensuring that they can be moved to the site), and assembled.

I don't suppose that everything works entirely according to plan, and of course there is no way that every future change request can be anticipated, let alone accommodated in advance, but for all practical purposes, this shows that if one is prepared to do what it takes, one can start the construction of a house knowing what you are going to get and with a detailed plan for getting there.

Computational technology has a particularly broad and active leading edge where unknowns are being tackled, but even so, most software development is nowhere near that edge.

The original point about houses is that with software, similar-seeming changes can have greatly differing costs, on account of what is hidden from the users' view, and I think the analogy works very well in making that point.