Please Stop Calling the New Bloomberg HQ the World's Most Sustainable Office Building. It's Not.

It's a great building with lots of green features, but there is more to sustainability than a high BREEAM score.

Mike Bloomberg is one of my favourite billionaire philanthropists, building his new European headquarters in London, one of my favourite cities, designed by Norman Foster, one of my favourite architects. But I do wish everyone would stop calling it "the world's most sustainable office building," which both Bloomberg and Foster (and every other website) do; it's not.

© Foster + Partners/ Bloomberg There is a lot of green goodness in this building, and it did get a BREEAM score of 98.5 percent, the highest ever for an office development. (BREEAM is a sort of British version of LEED). There are some really interesting innovations, like the ceiling, described by Foster + Partners:

© Bloomberg via Archdaily

Integrated Ceiling Panels: Bespoke integrated ceiling panels combine heating, cooling, lighting and acoustic functions in an innovative petal-leaf design. The system, which incorporates 500,000 LED lights, uses 40 percent less energy than a typical fluorescent office lighting system.

© Bloomberg/ Green features

It has serious water conservation measures that reduce consumption by 73 percent, including vacuum toilets. There is also a Foster favourite:

Natural Ventilation: When ambient weather conditions are temperate, the building’s distinctive bronze blades can open and close, allowing the building to operate in a “breathable” natural ventilation mode. Reducing dependency on mechanical ventilation and cooling equipment significantly reduces energy consumption.

© Bloomberg via Archdaily

Foster has tried this on a few buildings, notably the Gherkin, where nobody ever opens the windows. I suspect nobody will in the Bloomberg building either, given the awful air quality in London. But there are also "smart CO2 sensors that vary the amount of fresh air required when they are running the air conditioning, and a big combined heat and power (CHP) plant that supplies heat and power in a single, efficient system with reduced carbon emissions. Waste heat generated from this process is recycled for cooling and heating and, in use, is expected to save 500-750 metric tonnes of CO2 each year."

All of these are wonderful things; Foster and Bloomberg deserve much credit. But calling it "the world's most sustainable office building" just because it has a high BREEAM score doesn't make it so. For example, CHP plants usually generate heat and power by burning natural gas. The most sustainable office building in the world wouldn't burn fossil fuels.

© Bullitt Center

The Bullitt building in Seattle doesn't; it has solar power and gets its heat through ground source heat pumps. But it's not BREEAM; it is built to the Living Building Challenge standard.

The world's most sustainable office building would consider the embodied energy of the materials in it; Oliver Wainwright notes that "the embodied energy levels are not slight, given that it contains 600 tonnes of bronze imported from Japan and a quarry-full of granite from India." That doesn't even include the embodied energy of the concrete in it.

© Powerhouse Korbo/ Snohetta

The PowerHouse Kjørbo, an office building outside of Oslo designed by Snøhetta, was designed to produce not only more energy than it needs from its solar panels, but "generates more energy than what was used for the production of building materials, its construction, operation and disposal." It actually pays back its embodied energy.

© Foster + Partners/ Bloomberg

The Bloomberg HQ is a lovely, very green building and London is lucky to have it. (Really lucky -- Bloomberg might have built it somewhere else had he known Brexit was coming.) Bloomberg describes his ambitions for it:

We believe that environmentally-friendly practices are as good for business as they are for the planet. From day one, we set out to push the boundaries of sustainable office design -- and to create a place that excites and inspires our employees. The two missions went hand-in-hand, and I hope we've set a new standard for what an office environment can be.

© Bloomberg via Archdaily

It is a new standard, absolutely. But please, stop calling it the most sustainable office building in the world. It's not.