US vs Canada. Building Codes

I read something interesting on the Canadian Mortgage and Housing Corporation (CMHC) site,

"While there are many similarities between U.S. and Canadian codes, there are also some significant differences. Many Canadians may have the perception that Canadian codes are superior or that compliance with Canadian requirements should result in approval in the U.S., but in fact the performance levels specified in the IRC often exceed Canadian requirements".

"Scope: The IRC is more comprehensive and inclusive than Canadian codes. It includes requirements for plumbing, electrical and fuel gas..."

"Fire Safety: Some fire resistance ratings are longer. Requirements for escape windows and smoke alarms are more stringent..."

"Framing: Joist, lintel (header) and rafter spans are more conservative in some cases. Requirements for jack studs at openings in walls are more stringent..."

"Duct Sealing: All joints in ducts are required to be sealed, even if the ducts are run entirely within conditioned space..."

If you are interested you can read the rest of the article here.