The 2009 International Building Codes

and ANSI/TPI1-2007 Truss Design Standard


The International Code Council (ICC) is in the process of publishing their latest round of model codes. Of most importance to the truss industry are the 2009 International Building Code (IBC 2009) and the 2009 International Residential Code (IRC 2009). It is expected that within the next year many local and state jurisdictions will start to adopt and enforce these new codes. Some jurisdictions may move to them right away.


These new codes reference, and thus require, the use of the new metal plate connected wood truss design standard called ANSI/TPI 1-2007 (TPI-07). MiTek has been working hard to implement this standard in our truss design software, and it is now available in version 7.1.2. We have found that the most profound changes required by the new standard are in the plating area, but there are changes that affect lumber design as well.


Many component manufacturers will be expected to start running truss designs using TPI-07 in the near future. Because of the new and modified plating checks, we anticipate that some plate sizes will increase, but this will depend on the type of trusses you design. Our investigation of a representative group of trusses indicates an approximately 3% to 5% average increase in plate costs but less than a 1% increase in lumber costs over current design standards. Changes to individual truss designs may vary greatly. MiTek has provided a document entitled Plating Tips for ANSI/TPI 1-2007 to assist designers in mitigating the effects of these changes using various software options.


If you have any questions related to these changes, please do not hesitate to contact your MiTek engineer or our Software Technical Support group at 866-MITEKTS (648-3587) or

 This page last modified on 3/26/2009