OOA is a unique architectural practice located in Accra, Ghana, founded by Austrian trained Martin and Rosemary Orthner in 2006.

We successfully bridge two cultures, Europe and Africa, bringing extensive design and construction experience from both continents to bear on every single project, large or small.

Since December 2016 we are also the Austrian foreign trade representatives to Ghana.

We have partnered with a number of international firms like, HOK, CO-ARC, ARUP, PBP+W, or ZGF with clients as diverse as the WORLD BANK / IFC, ORACLE, Google and the IMF, and have been involved with some of Accra’s most distinctive landmark buildings in recent years.