Chen, J.F. Moretti, M. Pagani, C. Pierini, P. JACoW Geneva, Switzerland 978-3-95450-178-6 10.18429/JACoW-SRF2015-THPB006 English 1070-1072 THPB006 cavity HOM interface simulation coupling Contribution to a conference proceedings 2015 2015-12 http://dx.doi.org/10.18429/JACoW-SRF2015-THPB006 http://srf2015.vrws.de/papers/thpb006.pdf Recentely, we improve the BuildCavity code, which is a graphics interface to SUPERFISH for the study of superconducting cavities of elliptical shape. Now it works with latest SUPERFISH 7 and can be installed also on newer Windows system such as Win 7 and 8. Several improvements have been done in the code. As an example, a design of ESS median-beta cavity with BuildCavity will also be presented.