For three years, the architecture photographer HG Esch documented with impressive images the energetic renovation of the 'HVB-Tower' in Munich, which has been the head office of the HypoVereinsbank since 2016. The characteristic exterior of the building, mirroring the sky in accordance with the design idea of the original architects Walther and Bea Betz and whose color is constantly changing with the intensity and incidence of sunlight, was replaced by a technologically pioneering façade construction. It contributes significantly to the new sustainability concept for one of Munich's landmarks, achieving a significant reduction in energy consumption. A particular challenge for Hennarchitekten, HVB Immobilien AG and all others involved in the construction was the visual reconstruction of the distinctive outer appearance of the façade of the heritage-protected HVB-Tower, alongside all the technical innovation.