This chapter presents the approach followed for the development of the Norwegian national solution for patient-oriented eHealth services (here called HealthNorway). Our research interest is twofold: first, on understanding the initial design decisions and initial evolution in relation to the installed base of existing digital capabilities, and, second, on understanding how HealthNorway was further developed after the initial launch in relation to the long term vision of offering comprehensive and readily available health services to citizens. Drawing from the case, we identify different approaches for infrastructural development in the form of proactive cultivation strategies related to extending, complementing and creating substitutes within the installed base.The remainder of the chapter is structured as follows: we provide first a brief overview of the Norwegian health system and its digital infrastructure; we then introduce our case and present key activities, concerns and decisions for HealthNorway