I think in this thread people are kind of conflating office construction vs. cubicle construction. It's true that cubicle construction is pretty comparable to open plan in terms of cost and speed, but cubicles have a bad rep. If you're trying to do real offices, individual or small group, the cost goes up quite a bit.
For example, at least in NYC, the fire code dictates you need sprinklers and annunciators in every space, which increases the cost and complexity of the fire system. Plus, HVAC is much more complicated in office setups, as you can't rely on a large mass of air mixing to normalize temperatures, and have to manage longer vent runs with more exit points.
Then there's the problem that in a lot of buildings, particularly in urban areas, there's a relative paucity of windows, and people find windowless offices less desirable, making it harder to design office plans that don't shortchange big chunks of the employee base. One benefit of open plans is its a lot easier to give employees some view of sunlight and the outside.
For example, at least in NYC, the fire code dictates you need sprinklers and annunciators in every space, which increases the cost and complexity of the fire system. Plus, HVAC is much more complicated in office setups, as you can't rely on a large mass of air mixing to normalize temperatures, and have to manage longer vent runs with more exit points.
Then there's the problem that in a lot of buildings, particularly in urban areas, there's a relative paucity of windows, and people find windowless offices less desirable, making it harder to design office plans that don't shortchange big chunks of the employee base. One benefit of open plans is its a lot easier to give employees some view of sunlight and the outside.