- you can't design something before you have the requirements
- you can't code something before you have the design
- you can't test something before you do the coding
I mean, isn't it just a matter of building the skyscraper one layer at a time, why bother with planning?
Even though a skyscraper will be built one floor at a time from the bottom up, there still needs to be some architectural planning that happens first. The materials in the support structure of the building together with the common components that provide common services to each floor (plumbing, electricity, air conditioning) need to be planned out in advance.
Things that would be expensive to add after you have built a few floors:
- Needing an extra elevator
- Needing an extra floor in the parking garage
- Needing the entire building cabled with fiber optics