Currently there is no way with which a user of the Designer site may transfer the ownership of the questionnaire to another user, a task common when e.g. a user is leaving an organization, and wishes the remaining members to remain in control of the questionnaire, or if a consultant is creating a questionnaire which must be transferred as a deliverable.
The feature is standard in file sharing / cloud hosting environments, for example:
Currently the workaround is to copy the questionnaire. But this is inconvenient as this questionnaire will be assigned a new GUID breaking the linkage with versions already uploaded to the HQ, and also it will not be shared with the original counterparts, and other similar inconveniences.