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chapter is further amended by the Minnesota State Building Code to reference the 1992 CABO One and Two-Family Dwelling Code (OTFDC). The OTFDC requires that "far most soils," wood foundation walls "shall be designed assuming a lateral soil pressure of 30 pounds per cubic foot equivalent fluid weight."Since lateral soil pressures vary depending on the type of soil,higher design pressures are often warranted. It is the recommendation of AF&PA that PWF system design be in accordance with the most current edition of the National Design SpecificationOO for Wood Construction (NDSOO) and Supplement and TR7. AF&PA defers to Minnesota laws governing "design" for the purpose of enforcement of this requirement. Notchin�and Borin� AF&PA believes it is not the intent of the code to permit the notching or boring of wood foundation studs as permitted by sections 2320.11.9 and 2320.11.10 of the 1997 UBC for wall studs. The forces acting on a foundation wall stud may resist sizeable permanent forces,which are uncommon in above grade,exterior wall studs. Conversely,however, there is nothing in the code to prohibit notches and holes when designed in accordance with good engineering practice. As notches and holes remove fiber that is otherwise considered to be present when an analysis is performed, as long as a designer considers the loss of cross-section in an analysis, there is no reason to prohibit notches or holes. Other Sources of Information The International Residential Code(IRC)published by the International Code Council, provides a simple,prescriptive solution for the PWF. It is the position of AF&PA that foundations may comply with this prescriptive solution in lieu of design. Wood foundations must strictly comply with the prescriptive requirements in addition to the provisions of TR7. Under the IRC backfill is limited to 4' in height. Further, there must be equal height of fill around all sides of the foundation, and the distance between points oflateral suppart(the point at which an interior wall is perpendicular to and abuts the exterior foundation wall)cannot exceed the width of the building(cannot exceed the smaller of either the building length or width). Minimum dimensions and strength characteristics are specified in the IRC for wall studs, along with minimum thicknesses for plywood sheathing. When these limitations cannot be met, the prescriptive provisions of the code do not apply. Therefore, any structure or portion thereofoutside the prescriptive requirements must be competently designed.The requirement for design of the P WF is no different than it is for other structural elements which are not prescribed. ThePerrnanent Wood Foundation System,Design,Fabrication,and Installation Manual(DFI)is no longer published by the American Forest&Paper Association.Last published in 1987,the prescriptive design solutions are no longer in compliance with the model building codes or the National Design SpecificationOO for Wood Construction (NDSOO).Although the DFI has never been referenced in the model building codes, it has been popular as a guidance document for foundation designers, and the design details contained therein are still used by them. However,a Permanent WoodFoundation Design and Construction Guide,is now published by the Southern Forest Products Association on behalf of the Southern Pine Council. It provides the most current design and construction information prepared by the industry.The Guide is not referenced in the building codes, nor was it developed for that purpose. Rather, the Guide is intended to provide a homeowner, builder, designer, or building official with best practices reference materiaL It should not be considered an alternative to the requirement for structural engineering,unless recognized far that purpose by the State. American Forest&Paper Association Page 2