Digital media and digital data processing have substantially influenced public institutions in recent years and changed their efficiency, effectiveness and organisational set-up (nature of organisations). Based on Fountain's Technology Enactment Framework (TEF), this paper argues that, firstly, in a circular process, digital requirements transform the bureaucratic features of school organisation, and that the effects of digital technologies on the performance and efficiency of schools as bureaucratic organisations are ambivalent. We use interview data from a sample of 51% of the head teachers of vocational school centres in the jurisdiction of Bavaria in order to substantiate these assumptions by means of structured qualitative analysis. Email technology seems particularly significant from a quantitative perspective. Indications for the transformative nature of objective digital technologies with regard to the school bureaucracies can be found for all bureaucratic categories under consideration in this analysis, particularly for the feature 'standardisation'. The examples presented here seem to highlight that gains in efficiency or reductions of losses in efficiency caused by digitalisation are mostly caused by the concrete use of digital technology within the respective school organisation.