Abstract The tree-ring lab at BOKU University, Vienna, Austria has been sampling and dating by means of dendrochronology in the eastern part of Austria since 1996. Among other objects, the roof constructions of 982 historical buildings were analysed, resulting in 13 916 samples. The time span extends from the oldest roof truss at a church in Salzburg, dated to 1135, to the youngest in Vienna, dated to 1997. The aim of present paper is to provide an overview of the findings on historical roof constructions in Austria based on data collected over the last 27 years. Out of the total sample elements, 69.0% were made out of Norway spruce, followed by silver fir with 19.6%. All other species played a minor role: pine (5.0%), larch (3.6%), oak (2.7%), followed by a few elements made of stone pine, elm, beech, and poplar. The proportion of wood species reflects the significant influence of alpine regions. Within the city of Vienna, where all building timber was rafted, the amount of spruce wood is 72.3%. There were no clear visible changes in the wood species share over time. Along with dendro-dating, building historians have been analyzing the typology of roof trusses and the changes within time. It was possible to see clear alterations from simple rafter constructions to huge multi-level constructions with standing and sometimes hanging columns and roof constructions with lying posts (in the plane of the rafters) that transition back to constructions with standing columns.