by default roof access hatches can only be opened from the inside, using a handle and cylinder lock. When on the roof, however, it is possible to close the roof cover without it falling into the closure. Once the work on the roof is complete, the roof access hatch merely needs to be opened to allow access back inside.
There are two special solutions, but these are only available for roof access hatches without windows. It is possible to install both a closure and an electrically-operated closure on the outside. However, these options must be specifically requested.