Certain researchers studied on the history of the chateau-neuf of Versailles, the enveloppe by Le Vau. But they haven't any harmony with themselves about the traitement of the Louis XHTs chateau and the first design for the chateau-neuf. It is for the difficulty of three Colbert's documents. For resolve these problems, one must compare the analyses of the documents in the former researchs one of which, measuring the chateau, clarified that one wanted to conserve the Louis XIITs chateau. And some measurements given by Colbert indicate that there was an another precedant plan that one can reconstruct by these.