Introduce and discuss methodological issues on this very specific kind of PPP, as the ones concerning space development are. The methodology should have a common basis throughout societies that share the same legal and economic principles. This methodology should have a strong relationship with real estate appraisal procedures. The presentation will discuss conceptual basis for a methodology and refer to implementation problems and solutions whenever useful. Risk of PPP in Real Estate/Urban Planning can be mitigated for both parties provided an algorithm for planning gains determination is previously accepted.