The remaining ruins of the Roman Villa indicated very well the room structure of the former building, but in some aspects wall damages or lack of its volume obscure the original function or shape. Therefore, in some cases measures for completion and improvement of the buildings wall structure are undertaken, even if stability reasons cause renovating parts of them. The still preserved but strongly affected historic vault and half dome of the Trifolium had been basically reconstructed already in the twenties of the past century, but their afterwards bad appearance and ugly crack traces urged a treatment for bettering, so the joints in the cracks are remodeled and parts of the dome edges are repaired by setting of new stone blocks and refilling of deep holes with mortar. The present effect should indicate in a homogenous but differentiated way the repair and new treatment as well as the original remained dome parts.