Boltenhof, refurbishment and extension

Hamburg / Germany, 2009

Description
The „Boltenhof“ office block is located on “Mattentwiete” / „Bei dem Neuen Krahn“ within a building block comprising of several listed historic office buildings. Internally, the building was gutted down to the structural shell in order to realised modern supply engineering and office landscapes, and add an additional recessed floor, the sixth level. The staircase with its typical illumination and the façade were restored. All windows were replaced. With due consideration of preservation aspects, the original, horizontal division of the windows on the ground floor and first floor was maintained. As from the second floor upwards, double-casement aluminium windows with a vertical asymmetrical partition elements were built in. The recessed floors are designed with a post–and–beam façade, with its structure with alternating solid and glazed elements taking reference from the stone façade of the existing building. Brass cladding was used for the façade of the newly added storey and - as in the past - in the whole building. The outcome is an office building with a modern standard and the charm of an historical Hanseatic office building. The planning model was executed as general planner with a comprehensive range of services including project management.