This case study examines how a high school residential construction program switched from framing with conventional methods to Optimum Value Engineering (OVE) practices. It underscores the barriers to successful implementation of OVE techniques and presents realistic lumber savings.
Based on the case study, some OVE techniques were practical to implement (when visibly marked on the construction plans) and had noticeable material savings, thermal benefits, and positively affected the quality of framing. Other practices were found to be problematic, either from a technical or logistical standpoint, or had minimal energy or lumber saving benefits (considering that exterior foam sheathing was employed on the home).
The case study highlights the advantages of and barriers to widespread adoption of OVE practices. More conscientious attention to framing details such as right-sized headers, three-stud insulated corners, and ladder blocking at wall intersections, reduces unnecessary material use and increases the available space for cavity insulation. However, changes to conventional framing practices requires increased effort at the design stage and oversight during construction, with efforts diminishing as framing crews become more familiar with the new practices. For successful implementation, OVE details must be clearly depicted on architectural plans and easily referenced on the jobsite. On a first-time home, these added “soft costs” associated with the implementation of even the most basic OVE practices are likely to offset any savings accrued from reduced lumber use. Furthermore, the energy efficiency gains associated with using continuous exterior insulating sheathing overshadow the efficiency gains from employing OVE framing techniques.
Both an Executive Summary and a Full Report are available in PDF format.
NAHB Research Center
Report- 24 pages
Summary - 2 pages