World's Greenest Commercial Building
At first glance, one can’t help but notice the roof, which cantilevers out over the walls – extending like an umbrella over the building. It houses a solar array that is sized to provide 100% of the buildings energy needs (not an easy feat in such a dreary city). Not only that, but it is also designed to collect enough rain to be stored and filtered to suffice the building’s water demand. All building materials used for the project come from within 300 miles of the site – the stone used for all the concrete in the building comes from 30 miles away. All the wood in the building – and there’s a lot of it – is 100% FSC Certified and none of the building materials contain any traces of the 362 toxic chemicals red-listed by the Living Building Institute. The “irresistible staircase” entices occupants to walk up instead of use the elevator by offering stunning views of the city – and all occupants will benefit from natural daylighting.
Unlike traditional commercial buildings, which aren’t built to last much more than a few decades, the Bullitt Center is a 250 year structure built from heavy timber, concrete, and steel. The high performance envelope, or “skin”, has a 50 year lifespan and will be replaced as needed. The active solar controlled photovoltaic system has a 25 year lifespan and will either be repaired or changed out with the latest technology at the time of replacement. This understanding of varying lifespans will allow the building to keep its structural integrity, while staying relevant for centuries.
The Bullitt center is expected to be 80% more energy efficient than the average high-rise office building in the region. Perhaps more impressively, the building aims to be twice as efficient as the next “greenest” office building in Seattle (which is city at the forefront of the sustainable building movement). “If you took just the office buildings in the United States today, and reduced their energy consumption by half, you would be saving twice as much energy every year as America imports from the Middle-East,” explains Bullitt Foundation president Denis Hayes. The building will utilize radiant heating and cooling, a ground source heat exchanger, and a sophisticated heat recovery air system. It will be naturally ventilated and incorporate night flush cooling. The buildings 575 rooftop solar panels that stretch over 14,300sf will generate 240,000 kilowatt hours per year and provide 100% of the buildings energy needs. One of the most unique and interesting aspects of the buildings energy plan is an internal cap and trade system where each tenant is given an energy budget. "If they can operate their business within that energy budget, the Bullitt Foundation will write the check to pay their utilities bills," says Joe David of Point 32. "So a tenant who can live within their energy budget will never have to pay a utility bill while officing here."
The solar panel roof will also act as a rainwater collection system. The water that is collected will be funneled into a 56,000 gallon cistern where is can be stored, filtered, and purified until it is clean enough to drink. The goal will be to harvest enough rain to meet all the water demands of the building. There is one small hurdle though – it is currently illegal to convert rainwater into potable water. The plan is to collect data over the course of the first year of operation and work with local and federal policymakers to make the necessary regulatory changes. For now, they will use potable water from the city.
All greywater produced in the building will be collected in a 400 gallon tank and filtered through a roof garden. It will then be channeled outside into a drain field where it can help to recharge the groundwater. The building has the first 6-story composting toilet system, allowing all human waste to eventually be used as fertilizer nearby.
We won’t know if the Bullitt Center meets the mark set by the Living Building Challenge until a year after operation. If it is able to perform as it is expected to, it will be the certainly be one of the best examples of energy efficient building design to date. “It’s impossible to say that something’s impossible if it exists,” says Hayes, “and I wanted to get something that was concrete out there – that was functioning – that would serve as an example – because once you do something, then it becomes thinkable for everybody else to do it.”