Sustainability begins with preservation - maximizing the use of existing materials and infrastructure, reducing waste and preserving the historic character of older towns and cities. Land availability surrounding the locations/sites of most of historic and heritage buildings, original bioclimatic adaptability and currently available environmental technologies, including HVAC and mature technologies of renewable energies supply systems, can supplement inherent sustainable NZEB’s features without compromising the unique historic character. Presenting studies (Aviation Museum and Institute for Conservation) addresses methodologies, current knowledge and technologies use in refurbishment design process, as well as importance of relevant benchmarking, rating system and financing scheme development.