Energy

The modern portion of the building is set into the landscape, sheltering it from wind and allowing it to take advantage of some free cooling in the summer and warmth in the winter.

The building is laid out largely along an east-west axis, so that the long walls face north and south. Large expanses of glazing welcome daylight into the building, providing some passive solar heating in the winter and reducing the need for electric lighting year-round.

Exterior and interior lightshelves bounce the daylight deep into the building while reducing glare and limiting heat gain during the warmest part of the year, when the sun is high in the sky.

The modern sections of the building are insulated to double the levels of a conventional building. Extra insulation in the walls and roof as well as double-paned glazing help the building remain warm during the winter and cool during the summer.

Most of the building’s mechanical heating and cooling is provided by a ground-source heat-pump system. Below a few feet deep, the ground remains at a constant temperature – about 55 degrees Fahrenheit – throughout the year.

We tap this free air conditioning by circulating a fluid through wells located below our parking area. Our ground-source system employs 40 wells, each drilled 400 feet deep.

During the winter, the system moves heat from the ground into the building; during the summer, the system moves heat from the building into the ground.

Instead of a conventional ventilation system, which delivers fresh air from the ceiling, the office space relies on an under-floor air-distribution system. This system allows air to be delivered at a slightly warmer temperature during the summer and a slightly cooler temperature during the winter, saving energy. It also enables occupants to control airflow in their offices by adjusting grates in the floor.

When daylight is insufficient, the building uses efficient, fluorescent lighting fixtures. Daylight sensors turn off the lights when artificial lighting is unnecessary, and occupancy sensors turn off the lights when rooms are not being used. Offices also include task lighting, allowing many employees to control the amount of light in their workspaces.

We purchase all our electricity through a GreenCurrents program, made available through our utility. That program promotes the development of renewable energy sources in Michigan.

Materials

The design team selected materials with consideration for their impact on the health of the building occupants as well as the environment.

The headquarters incorporates a house, a barn and several outbuildings original to the site’s 19th-century Brooks Farm. The reuse of these buildings prevented the extraction, manufacturing and transport of significant amounts of materials, reducing the embodied energy of the overall project.

When possible, the project team selected new materials that included recycled content. Examples include the steel, carpeting and terrazzo flooring used in the building.

The project team also preferred materials that were manufactured or extracted regionally, reducing the energy needed to transport them to the site. More than 75 percent of all materials used on the project, measured by cost, were manufactured within 500 miles of Troy. In addition, 13 percent of all raw materials were extracted within the same radius.

The most local material employed at the project was paving material and other rock recovered on site during demolition and construction. This material was placed in wire baskets that were used in place of concrete to build retaining walls.

These walls – called gabion walls – not only reduced the need for transportation of materials, but also reduced the amount of construction and demolition waste that had to be disposed of in a landfill. In addition, they reduced the need for concrete, which is a highly energy-intensive building material.

Some materials are made of rapidly renewable materials. Examples include:

• furniture, doors and mill work with wheatboard cores.
• paint made from milk.
• linoleum flooring made from linseed oil.

The building also features wood that was harvested in a sustainable manner. In all, 84 percent of wood products used in the building, measured by cost, were certified by the Forest Stewardship Council.

To protect the health of the building occupants, the project team specified that all adhesives, sealants, paints and carpets emit low or no levels of volatile organic compounds.

Indoors

Ensuring a healthy and comfortable working environment is a high priority.

• 92 percent of all workspaces have ample daylight.
• Almost all workspaces have views outside.
• We use paints, carpet, cleaning products and composite wood and agrifiber products that release low or no levels of volatile organic pollutants. Paints are certified by Green Seal; carpets comply with the Carpet and Rug Institute’s Green Label program.
• Carbon dioxide sensors ensure that the ventilation system provides adequate fresh air, even when rooms are crowded.
• Two interior waterfalls were installed in 2010 largely to increase humidity. They also add an engaging visual element to the building and provide a quiet background noise in the building’s largest open work area.