Christiansen O'Brien Pty Ltd is a Sydney-based architectural firm founded on thirty five years collective experience within the architectural and construction profession, and twenty years of specialist experience in major retail developments.

Directors, Neil Christiansen and Denis O'Brien established Christiansen O'Brien in May 2005 as an architectural practice offering a unique depth of knowledge and experience, combined with commercial sensibilities across all design spectrums.

Our aim is to work with clients through planning, politics and the commercial reality as part of a team in a inclusive process.


"Our concept responds to opportunities and constraints to provide cost effective, imaginative solutions."



  • Mixed Use
  • Residential Apartments
  • Residential Single Dwellings
  • Commercial
  • Industrial
  • Retail
  • Interior Design
  • Council Liason
  • DA Management