Bloomberg's new European headquarters designed by Foster + Partners is the world's most sustainable office building. According to BREEAM, it achieved an 'outstanding' rating with a score of 98.5%, which is the highest design-stage score ever achieved by any major office development in the world.
Located in the heart of London, the new Bloomberg headquarters has become a natural extension of the city by creating new civic spaces in the middle of the Square Mile. The nine-storey building is the size of a full city block, occupying a 3.2-acre site. The design splits the building into two blocks connected by bridges over a pedestrian arcade on Watling street. Three new public plazas are introduced in the city, at each end of the arcade and one in front of the building's entrance activating the ground plane.
"Bloomberg Arcade is now a key route for people moving around the City, with restaurants and cafes at ground level, set back behind an undulating façade under a covered colonnade. Three public plazas, located at each end of the arcade and in front of the building's entrance, provide new civic spaces in the heart of the Square Mile." Explains the Studio.
The new city square at the building's entrance leads the visitors to the reception area where people are drawn into the double-height Vortex, created by three inclined, curving timber shells. From here, the visitors can take fully glazed lifts to the double-height pantry located on the sixth floor, referred to as the heart of the building.
"Central to Bloomberg's ethos, the double-height 'pantry' on the sixth floor is the heart of the building, reflecting the importance of sharing and collaboration at the company. Everyone passes through this animated space, increasing the likelihood of chance meetings and informal discussions." Explains the Studio.
The Studio Continues, "A distinctive hypotrochoid stepped ramp, characterised by its smooth continuous three-dimensional loop, flows through the full height of the building, adding to the drama of the space. Clad in bronze, the ramp is designed and proportioned as a place of meeting and connection, allowing people to hold brief impromptu conversations with colleagues, whilst not impeding the flow of people."
The building utilises several key strategies to achieve BREEAM Outstanding rating and become one of the world's most sustainable office buildings.
"Compared to a typical office building, its environmental strategies deliver a 73% saving in water consumption and a 35% saving in energy consumption and associated CO² emissions. At 600 tonnes per annum, this CO² reduction equates to driving a domestic car 120 times around the globe." Said Foster + Partners.
Teamwork and collaboration are central to the design, and moments are created throughout the building to encourage that. The architects designed bespoke ceiling panels for the building, which combines heating, cooling, lighting and acoustics function in an innovative petal leaf design. The metal petal's large surface area is integrated with elevated chilled water temperatures to reduce the energy use. The panels hold 0.5 million LED lights and provide 40% energy savings than a typical office lighting system.
The building's striking facade is made up of structural sandstone frame and large bronze fins, providing solar shading to the inner spaces. When outside weather is temperate, the exterior fins can be opened, allowing the building to operate in a 'breathable' natural ventilation mode. The central atrium acts as a chimney allowing the natural air to flow through and out of the roof, reducing the dependency on mechanical ventilation and cooling equipment to significantly reduce energy consumption.
Smart CO² sensors distributed throughout the building can dynamically adjust airflow based on occupancy hours and patterns and result in significant energy savings. "Smart CO² sensing controls allow air to be distributed according to the approximate number of people occupying each zone of the building at any given time. A typical floor, where there are circa 775 workstations, has 68 such CO² sensors. The power saved by adopting this approach is expected to be 600- 750 Mwhr per annum. As a result, projected CO² emissions resulting from Bloomberg's occupancy are reduced by 250-300 tonnes per annum." Said Foster + Partners.
Bloomberg Headquarters generates power on-site by using the Combined Heat and Power (CHP) generation centre that supplies heat and power in a single, efficient system to further reduce carbon emissions. The Studio Explains, "Natural gas is converted to power and the waste heat generated in the process is also used in the building either for heating and hot water, or to generate cooling, via an absorption chiller for Bloomberg's technical facilities. In use, the CHP system is expected to save 500-700 metric tonnes of CO² each year. Photovoltaic cells on the roof of the building also supply additional power."
Bloomberg building roughly uses 70% less potable mains water than a typical office building. The rainwater from the roof, cooling tower blow-off water, and greywater from basins and showers is captured, treated and recycled to serve vacuum flush toilet. Since all the flush toilets in the buildings are served using recycled water, the building uses net zero mains water for flushing.
During the construction process, the building used bespoke concrete made up of 60% recycled aggregate, which ultimately diverted 60,000 tonnes of waste product out of the landfill and reduced carbon productions by 60%. To further mitigate embodied energy during construction, the building re-used existing structural foundations. The team also used a unique waste management system, which used barcoded wheelie bins and tracked waste production throughout the project. This resulted in a 95% recycling rate for demolition and construction waste.
Bloomberg building was awarded the Stirling Prize, with the judges calling it a "once-in-a-lifetime" building that has "not just raised the bar for office design and city planning but smashed the ceiling."
Foster + Partners is a global studio for sustainable architecture, engineering, urbanism and industrial design, founded by Norman Foster in 1967. Since then, he, and the team around him, have established an international practice with a worldwide reputation. With offices across the globe, we work as a single studio that is both ethnically and culturally diverse.