This volume is the first in a new series of workshop proceedings, an initiative that promises to make focused discussions and updated expertise available quickly to the scholarly community. The volume is a good illustration of the concept, gathering experts on architectural ornamentation around a specific set of ideas, illustrated through case studies. Two caveats are necessary: firstly, the involvement of the sadly departed Wulf-Rheidt is limited to supporting the idea of a publication, and those hoping for posthumous work should look elsewhere. Secondly, the volume concerns unfinished surface decoration, not abandoned building projects, and all the case studies concern structures that became employed for their intended purposes. Much of the information provided is technical, and the volume will primarily be of interest to art historians with a special interest in architectural ornamentation. That said, it also feeds into a wider discussion on the priorities that define building projects, and as such merits a wider readership.

The introduction by Geißler sets out the methodological focus. The stated aim is to open a discussion on the phenomenon of incompletion, not to provide answers as to why structures were left unfinished, although most contributors offer suggestions. The volume is divided into two parts, the first technical and general, the second setting out a number of case studies. The technical part includes two chapters co-authored by J. Giese and M. Grawehr, one on the terminology of embossed masonry (‘Terminologie und Stellung in den antiken Werkprozessen’) and one on the gliding meanings of ‘incompletion’ (‘Zur Unterscheidung von Unfertigkeit – Auslassungen, Reduktion und Bossenstil’). These are followed by two chapters by Grawehr on ‘Bossenstil’, meaning the deliberate choice of leaving bosses raw (in English usually termed ‘rustication’), one on scholarship (‘Die Erforschung des Bossenstils in der antiken Architektur’) and another on application (‘Unfertigkeit als Stilmittel – Erscheinungsform und Vorkommen’). The terminologies proposed in the more technical sections are not immediately translatable to non-Germanic contexts and would need to be adapted to other languages and traditions of stonemasonry. More generally useful is the discussion on ‘Bossenstil’, including motivations for the choice and the risk of circularity when analysing it, as for instance the convention of dating rusticated structures to Claudius’ reign.

Among the case studies, the first is also the fullest, concerning the Porta Nigra in Trier (Geißler, ‘Die Porta Nigra in Trier – Ein Beispiel für die Inbetriebnahme eines unfertigen Bauwerkes’), which provided the initial inspiration for the workshop. Its surface decorations are confirmed as accidentally unfinished, while the monument of the Ubii in Cologne (A. Schäfer, ‘Bossen- und Spiegelquader am römischen “Ubiermonument” in Köln’) presents examples of both incomplete elements and ‘Bossenstil’, which Schäfer suggests was meant to underscore the heavy-duty aspects of the structure. A survey of comparanda from Gaul and Spain (M. Trunk, ‘“Unfertige” Kapitelle und Säulenschäfte im römischen Westen – Ausgewählte Beispiele aus Gallien und Hispanien’) is followed by two chapters on Carnuntum (G. Kremer, ‘Unfertigkeit an Weihedenkmälern in Carnuntum’; H. Thür, ‘Unfertigkeit an der Architektur in Carnuntum’), treating unfinished decoration on altars and architectural pieces respectively. Three case studies on Asia Minor (G.A. Plattner, ‘Unfertigkeit und “Effizienz” in der römischen Bauornamentik Kleinasiens’; B. Emme, ‘Systematische Auslassungen und semantischer Gehalt beim Ornamentsystem der “ara augusti” im Buleterion von Milet’; Giese, ‘Der Rohbau als unfertiger Baukörper – Zum Verhältnis von Roh- und Ausbauphase an einem kaiserzeitlichen Bau in Alexandria Troas’) treat different expressions of, and approaches to, unfinished decorations, followed by an essay on funding (U. Quatember, ‘Die Finanzierung von Bauvorhaben und ihr möglicher Zusammenhang mit Unfertigkeit – Kleinasien in der römischen Kaiserzeit’). The volume is rounded off by a brief epilogue by the editor.

One of the main strengths of the volume is how it probes the limits of the aesthetically possible, especially in cases where accidentally unfinished ornamentation is left in that state over succeeding centuries, indicating a high tolerance for imperfection. One example is the Serapeum in Ephesus (Plattner), an iconic building raised at a place and time where money or artisanal skill should not have presented problems. Equally significant is the unfinished decoration on the Porta Nigra, especially given Trier's later role as an imperial residence. In both cases, visibly unfinished ornamentation was apparently acceptable. Among other strengths of the volume are the glimpses provided of the complexities of the work process and, in spite of the caution expressed in the introduction, the reasons suggested as to why structures were left unfinished (e.g. military conflict, cost-utility calculations, lack of funds, change of plans, death of the architect or commissioner, redeployment of the workforce). The chapters on Carnuntum add factors to do with the town's comparatively peripheral location, such as miscommunication, and low or time-limited access to skilled artisans (Kremer). Of particular interest is how what was initially pragmatic choices for architectural ornamentation developed into its own, deliberately chosen aesthetic (Thür).

Among the volume's weaknesses is a tendency to gloss over the different meanings of ’unfinished’, which in English presents the same double sense (undressed masonry and incomplete execution). Although recognised, especially in the theoretical first part, these difficulties are not tackled consistently in all chapters, in spite of repeated calls for terminological precision. Arguably bending the terms too far is a study of a structure that was once finished with revetment, but of which only the shell survives today (Giese), which reveals a great deal about the work process but less about ’unfinished’ buildings. One would also have liked to see an attempt to extract observations from across the comparanda. Although not uninteresting, the essay on funding (Quatember) concentrates on public building in Asia Minor, leaving out infrastructural work, which forms a large part of the western case studies. Seeing the technical bent of the volume, a chapter on, for instance, quarry ownership, building collegia or military engineers would have been welcome and would have made the volume more broadly useful. Even so, it remains a thoughtful and competent examination of the subject at hand and essential reading for anyone studying the specific structures treated in the case studies.