On 29-Apr-2005, "J" wrote:

This is the classic case, but it is NOT a case of overdesign.

Over design version "just throw some more rebar in there - it's
never bad to overdesign".

But, we are considering overdesign. In this case we must assume that the
design with the lighter beam is SUFFICIENT to carry the load. It is not
expected to fail. Thus a heavier beam would be sufficient as well

For the design load - yes. For the actual load - no. See my other post.
The issue is whether you get warning of impending failure. Overdesign
can result in brittle failure without warning.

Wouldn't the supports be overdesigned as well?

The case from which this derived is one where someone is considering
a single element, not designing the whole building. If someone in
a forum like this who is not an engineer or architect gets hold of
a ridiculous claim like "overdesign is never bad" all sorts of
unexpected evil can result.

Perhaps you can quote the regulation that states this?

Criminal Code in Canada.

Mike.