At Technische Universität Dresden in a research project sustainable and transparent roof constructions have been developed. At these structures, on the basis of a double layer grid, the glazing is part of the primary load bearing system and transfers significant in-plane loads. The panes are connected by steel knots at their corners.

In 2007 the first project using this new concept was launched. With a dimension of 15 m x 21 m and an arch rise of 3.50 m it covers the courtyard of one of the Berlin palaces.

The design process was attended with extensive testing to obtain an individual approval. This contribution describes the testing at single panes and the full-scale arch of 15 m span.

Plastics for the in-plane load application into the glass edge and their creeping behaviour was investigated in first tests. The stability behaviour against glass pane buckling was tested at relevant load combinations and the post breakage robustness and the walk-on ability of the overhead glazing ensured by suitable test. Load bearing tests with a total load of 13 tons was applied on one 15 m arch and finished the test series.

The successfully finished testing is the basis for the individual approval and the realisation of the roof construction within the next month.