[LoneRangerMassachusetts]

One could probably take out half the studs in a typical residential wall without affecting the structural integrity of the building; the requrement of having studs every 16" is to allow people to lean on walls without them bending--not because it's necessary to support the weight of the roof or upper floors.

Wall studs are spaced at 16 inches mostly for the convenience of modular wall board which comes in increments convenient for this spacing. As a result many walls have far more strength than needed for carrying loads.

This is not the case with floors and roofs. They are sized more for strength.

For non residential buildings, you can count on the savvy owner to make designers just provide enough strength to meet codes.

[supercat]

Wall studs are spaced at 16 inches mostly for the convenience of modular wall board which comes in increments convenient for this spacing.

Right, but the design reason for that standard has to do, I suspect, with making the walls be able to withstand reasonable 'point' horizontal loads without the wall materials having to be excessively thick.