Perhaps the correct analogy is that the building of a skyscraper is akin to copying software (i.e., building a new replica of a design). In this regard software is the ultimate engineering. Once you have the blueprint (the final source code), stamping out copies is perfectly reproducible. The program applies to many more environments than a skyscraper design.
On the other hand, designing a skyscraper is alot like writing software. The designer doesn't know what the building will look like. There is an iterative process where ideas are thrown around, design errors identified and fixed, etc.
In terms of quality measurements, the same measurements don't apply to software since each copy is a perfect replica. There is little need to measure how closely a copy reproduces the design, it is often perfect. The design may have flaws, but so may a building design.
Having said this though, it sure seems that software is alot more unreliable than most bridges and buildings, so the question is, "Why?"