Alle Firmen mit dem Anfangsbuchstaben I
- Ing. Ruggenthaler Ronald
- Ing. Rulitz Dieter
- Ing. Rummel Gesellschaft m.b.H.
- Ing. Rumpelmayr Stefanie
- Ing. Rumpf Florian Herbert
- Ing. Rupert Klausbauer Beteiligungs GmbH
- Ing. Rupert Schmied KG
- Ing. Rupert Weber e.U.
- Ing. Ruthardt Herwig
- Ing. Ruthmair Johannes
- Ing. Ruttmann Franz
- Ing. Ruzicka Walter
- Ing. Röck GmbH
- Ing. Rögelsperger & Co. GMBH (RÖCO)
- Ing. Rögner Hannes
- Ing. Römer Rene
- Ing. Röschel Walter
- Ing. Rößler Bernhard Maria
- Ing. Rößler Vanessa
- Ing. Rößlhuber Magdalena Daniela
- Ing. Saber Reza
- Ing. Saber Zaeimian Abdol Reza
- Ing. Sabine Horvath GmbH
- Ing. Sabrsul Thomas-Florian
- Ing. Sackl Gutruf Thomas
- Ing. Sackl Josef
- Ing. Safrin Egon
- Ing. Sager Philip
- Ing. Sagmeister Kurt
- Ing. Sahl Martin Franz
- Ing. Sailer Josef
- Ing. Salfelner Gerhard
- Ing. Sallarova Anna
- Ing. Sallegger GmbH
- Ing. Saller Richard
- Ing. Sallmayer Thomas Gerhard
- Ing. Salzer Katharina
- Ing. Sammer Alfred F
- Ing. Sammer Guntram Herbert
- Ing. Sampl Alois
- Ing. Sams Günther
- Ing. Sand Michael
- Ing. Sander Heinrich
- Ing. Sandhofer Robert Josef
- Ing. Sandner Wolfgang
- Ing. Sangir Cem Devrim
- Ing. Santner Franz Michael
- Ing. Saria Rudolf
- Ing. Sattler Wolfgang
- Ing. Saustingl Johann
- Ing. Savinsek Igor
- Ing. Scalick Rudolf
- Ing. Schabauer Johann
- Ing. Schachenhofer Andrea
- Ing. Schachinger Herbert
- Ing. Schachinger Nina Theresa
- Ing. Schachner Harald
- Ing. Schaffer Josef
- Ing. Schafferhofer Markus
- Ing. Schafhauser Martin
- Ing. Schafhauser Michael David
- Ing. Schalk Friedrich
- Ing. Schalk Isabelle Patricia
- Ing. Schandl & Szuppin Installations GmbH
- Ing. Schania Johann
- Ing. Scharl Christian
- Ing. Scharler Elisabeth
- Ing. Scharner Peter Franz
- Ing. Schartner Michael
- Ing. Schartner Rudolf
- Ing. Schatz Bruno Patrick
- Ing. Schauer Günther Karl
- Ing. Schauer Walter
- Ing. Schauerhuber Julius
- Ing. Schaumberger Andreas
- Ing. Schaupmann Franz
- Ing. Schaur Alexander
- Ing. Schebesta-Ganzberger Katharina
- Ing. Schedlbauer Guido
- Ing. Scheibl Peter