With a Higgs boson discovered at LHC, but no other unambiguous sign of physics beyond the standard model seen so far, the question of naturalness of the electroweak sector and its suitability as guidance of future experiments becomes a more and more pressing issue. During this 3-day workshop, we will discuss status of naturalness in the context of all kinds of extensions of the Standard Model. In particular, we will confront different measures of naturalness and discuss the interplay of UV- and IR-based definitions. Each session will have ~2 presentations and ample room for discussion. Everybody is welcome to participate and people interested in giving a presentation should contact the organizers. A limited number of rooms in the DESY hostel has been reserved. Please tick the corresponding box during registration if you'd like to book one of them - we will assign them on a first-come-first-serve basis. We have the possibility to support postdocs working on naturalness-relevant questions to come to Hamburg for 2-3 weeks around the workshop - please contact Christophe.Grojean@desy.de or Jenny.List@desy.de in case you are interested!