CAD/CAM techniques for rapid prototyping, profile cutting, and form sculpting/routing/moulding are well-advanced for the vehicle and manufacturing industries. Although their migration to the building sector is readily achievable as a substitution for much of traditional construction, there are factors that work against this. Apart from the singular `one-off'nature of most architectural projects that limits ready exploitation of techniques derived in the main for mass-manufacture, there remains the problem of apprenticeship, and how to maintain a healthy lineage of skills for work otherwise less readily taken-up using automated manufacturing procedures. Continuing construction for Gaudi's Sagrada Familia Church in Barcelona has provided a fertile test-bed for integrating rapid prototyping and CAD/CAM production where appropriate. Nevertheless, human factors such as maintaining the status quo with regard to apprenticeship and maintaining the skill lineage have provided some healthy insights into both the risks as well as the opportunities for greater involvement with CAD/CAM, and in particular, rapid prototyping in the building construction sector. This paper reports on and discusses the findings of case studies from the Sagrada Familia Church project.