With its neutral façade and flat roof, the Bullitt Center may not be as visually striking as some of its other smart buildings counterparts. But inside its simplistic exterior is some of the most inventive energy and water efficiency technology available, which makes the Bullitt Center one of –if not the most- sustainable office building in America.
Created by environmental charity the Bullitt Foundation, the building was the vision of its CEO, Denis Hayes. He wanted to create a building that leads the way in sustainability to encourage more planners, architects and builders to follow suit.
Opened on Earth Day, April 22 2013, the Bullitt Center was created with a 250-year lifespan. The 50,000 sq ft office and educational space is classed as a ‘living building’, as it produces at least as much energy as it uses in a year, while every aspect of the design is to create a healthier workspace for employees.
The Bullitt Center was designed by Seattle architects, Miller Hull Partnership. Following an ‘integrated design’ method was crucial for the building’s creators. This holistic approach views the building as an interdependent system rather than an accumulation of separate components, which means a performance-based design approach was taken. Every aspect of the building was created with the goal of achieving net-zero waste in mind.
Ecotect, sustainable design analysis software from Autodesk, was used to study potential energy loss and gain from the building. These studies revealed that installing more south-facing windows would reduce heat loss. Each window unit is designed to eliminate thermal bridging between the interior and exterior. Two inches and three panes of glass keep the hot air out and cool air in during the hot summer days, and the cold air out and warm air in during the cold winter days.
The unique flat roof of the Bullitt Center houses most of the building’s 14,300 sq ft of solar panels. The immense energy generated from these are integral to the ‘net-zero’ goal. Additionally, 26 geothermal wells that reach as deep as 400 ft provides a form of clean energy to power the building that generally goes untapped.
The Bullitt Center is not only energy neutral but water neutral too. A parapet roof captures rainwater and brings it to downspouts that carry the water to a 56,000-gallon, concrete cistern in the basement, while Water from sinks and showers is stored in a greywater tank and cleaned in a constructed wetland. The building also boasts the world’s only 6-storey composting toilet system using waterless toilets. However, the building owners promise there is no odour as the decomposition process is strictly aerobic, which eliminates the release of methane gas.
Healthy workspace, healthy workers
When the Bullitt Center was being designed, the wellbeing of its inhabitants was considered equally important as its environmental impact. As a rule, workstations must be located no further than 30 feet from an operable window. To address these requirements, architects designed the interior with an atrium layout to get more of the floor plate close to a source of daylight and fresh air. This design means 82% of the interior has natural daylight.
Sensors connected to the building’s central nervous system monitor light levels, CO2 levels, temperatures indoors and outdoors, as well as wind and sun, to control and deliver heating, cooling, ventilation and illumination efficiently and effectively.
An “irresistible stair”, designed with glass walls to showcase the local views has been highly successful in reducing elevator use. The building is served by numerous public transport options, and actively encourages occupants to walk to cycle to work, with showers and bike storage available.
A leading commitment to ‘net-zero’
The Bullitt Center does not use particularly unusual design aspects for a modern building, and the technology used is readily available. But so far there are only a handful of buildings that have fully integrated the energy saving technologies and high-performance design strategies to the extent of the Bullitt Center.
The building design’s focus on employee wellbeing showcases that the Bullitt Center is committed to looking after both the planet and its residents, and the Bullitt Foundation hopes the success story of its building will encourage others to adopt similar practices and technology.