The legal relationship between architects and clients suffers from two basic tensions that have been debated in several European countries. First, the market for design of buildings is not the exclusive domain of architects anymore. Other disciplines have gradually encroached on the architect's core activities. Many new forms of contract have been developed in the construction industry. These market models no longer fit the traditional design contract, departing from the idea that an architect designs a structure that is fit for its purpose and subsequently supervises the realization of the design by the building contractor. Second, designing buildings is a low yield/high risk endeavor. If the obligations of architects under the design contract are not performed well, they are exposed to severe liabilities which may cause serious financial problems. Detailed comparative research on design contracts shows that rule makers have difficulties in dealing with these two tensions. In Europe, considerable differences exist regarding the national rules that apply to the contractual relationship between architects and clients. Therefore, in this study, four regulation issues have been investigated that deal with establishing rules to govern the two tensions: market entry regulation, architect liability, limitation of architect liability, and professional liability insurance. In order to evaluate these regulation issues, a law and economics perspective is applied. The book will help to establish which combination of regulation options is likely to lead to more efficient outcomes. It provides insights in what is the best way to deal with the two tensions in the relationship between architects and clients, and it contributes to establishing a new design for European architect law.