Both the International Residential Code (IRC) and the International Building Code (IBC) require that the top plates of exterior braced wall panels be attached to the rafters or roof trusses above. Note that this connection is only required for designated exterior braced wall panels, not all exterior walls. The IRC provides requirements and options based primarily on Seismic Design Category and height from top of wall to the top of the roof framing. The IBC requirements are less complicated. 

This report will discuss the code requirements and provide alternate engineered designs and capacities, including heel/bird blocking, partial height blocking and blocking panels. 

Heel blocking is a commonly used method to transfer in-plane lateral loads from the braced wall panel to the roof diaphragm. Structural engineers may have questions regarding the prescriptive code requirements or the capacity of commonly used heel blocking to achieve a desired load transfer. In addition there may be questions as to who is responsible for the determining the required strength.