Most of the surviving stave churches in Norway were built 1150–1350. Stave churches older than the 1100s are known only from written sources or from archaeological excavations, but written sources are sparse and difficult to interpret. Only 271 masonry churches were constructed in Norway during the same period, 160 of these still exist, while in Sweden and Denmark there were 900 and 1800 masonry churches respectively. Frostathing Law and Gulating law rules about "corner posts" shows that stave church was the standard church building in Norway, even if the catholic church preferred stone. All wooden churches in Norway before the reformation were constructed with "staves". Log building is younger than stave building in Norway and was introduced in residential buildings around year 1000. Stave building is not influenced by the log technique.