DESIGN PRINCIPALS | COMMERCIAL INTERIOR DESIGN STUDIO WE PROVIDE “A LA CARTE” COMMERCIAL INTERIOR DESIGN SERVICES. Consider us your on-call interior designers. Utilize our services for an entire project, only specific parts of a project, or just to support your staff when needed. We are flexible enough to enhance any commercial interior environment. For more information on our services and to view a sampling of our work, please visit www.DesignPrincipals.com.