ArcelorMittal’s HISTAR®/ASTM A913 steel in Grade 70 for 425 Park Avenue

Detailed information

The characteristic tapered design for 425 Park Avenue was created by Norman Foster’s architectural firm Foster + Partners who reimagined the existing 27-storey building dating back to the 1950s in close collaboration with L&L Holding’s project team. A decisive design requirement was the incorporation of 25% of the existing structure into this fresh, modern full-block office tower by melding old with new – a requirement that called for a complex structural design and added further challenges to the construction process.

The 248-metre-high building is vertically divided into three clearly recognisable volumes: The seven-storey base at street level is tightly knit into the urban surroundings, while a recessed central section and a slender top floor section complete the modern landmark. The volumes are separated by double-height spaces that intersect the office floors. The building’s three concrete cores are located at the rear and surpass its roof level in the shape of three steel framed fins that reach almost 50 metres into the New York sky, making it stand out from the rest of the city’s skyscrapers.

425 Park Avenue was designed to achieve LEED Gold certification and be New York’s first WELL certified building, a building standard that incorporates a holistic approach to health in the built environment with its occupants’ and visitors’ wellbeing at its centre.

A 30% weight reduction and column-free office spaces with HISTAR®/ASTM A913 Grade 70 steel

In order to fulfil the architect's vision of a 21st century office building with flexible, column-free spaces flooded with natural light, steel was the natural material choice thanks to its high strength-to-weight ratio and long-span capabilities.

The design team specified ArcelorMittal’s high strength HISTAR®/ASTM A913 steel in Grade 70 for the larger columns, further improving steel’s already high strength-to-weight ratio and resulting in a remarkable weight reduction. This reduction resulted in steel savings of 30% for the structure. The exterior columns integrated into the facade are also made of HISTAR®/ASTM A913 Grade 70 steel in order to keep their footprint to a minimum.

Of the almost 8000 tonnes of steel used for the structure in this building, ArcelorMittal supplied 2400 tonnes of HISTAR®/ASTM A913 Grade 70 steel, produced at its mill in Luxembourg.

The material and weight savings achieved thanks to the use of HISTAR®/ASTM A913 Grade 70 steel and the recycled content of structural steel in general contributed positively to attaining the LEED Gold certification.

Further details about 425 Park Avenue’s structural design and the construction process can be found in the article ‘Park Avenue Premiere’.