Mining For (LEED) Gold: Colorado School of Mines Renovation

By Jolynn Bennett, Pavestone, LLC

Renovations at and around the Colorado School of Mines' Brown Hall had to accommodate high levels of foot traffic, and included converting an adjacent street into a pedestrian walkway. Campus officials and the design team selected Pavestone's Eco-Priora• permeable pavers for the area, installing 35,000 square feet to accommodate emergency and service vehicles, avoid exceeding historic off-site storm flows, and meeting campus maintenance requirements for a long-lasting, durable pavement surface.

The Colorado School of Mines in Golden, Colorado, has a long history of connecting to the area's natural resources. Since the 1870s, the school has offered studies in chemistry, metallurgy, mineralogy, geology, botany, math and drawing, and has expanded its focus to modern energy and environmental concerns. A master plan to renovate Brown Hall, which houses the engineering and mining engineering departments, was drafted to meet LEED Silver standards.

Master Plan Goals
The new design for Brown Hall and renovation of the surrounding landscape crafted a compelling pedestrian environment in the heart of the campus.

The pavement profile captures water in places where slopes exceeded 8 percent. This required site specific detailing, including subsurface check dams and subdrains, since typical designs are for slopes less than 5 percent.

"The success of the first phase resulted in an extension of the use of the pavers in this new area," said project designer Mathew Evans, RLA, ASLA, LEED AP, Lime Green Design. "An unanticipated second phase of the project led to the "pedestrianization' of another section of street. As part of the master plan, a preliminary study identified another two blocks of city street extending out from the original Brown Hall project which will eventually be vacated, and the plan currently shows the continued use of permeable pavers in this new pedestrian spine." The campus paving needed to be practical and beautiful. Designer Evans, architect Anderson Mason Dale, installer JC Coniff, Rocky Mountain Hardscapes, LLP, civil engineer S.A. Miro, and the Colorado School of Mining's planning, construction and facilities management teams agreed to the selection and installation of 35,000 square feet of Eco-Priora• permeable pavers, manufactured by Pavestone, LLC.

Design and Construction Challenges
In addition to pedestrian traffic, the paving had to support the weight of fire trucks, service vehicles and the occasional 18-wheeler. With an average annual snowfall of over five feet, the pavement also had to be durable enough to sustain regular snow plowing. The construction schedule was also dictated by the school year.

The designer and contractor worked together on careful detailing of edge conditions around utility manholes and valve covers to accommodate the paver geometry and layout.

"Specific site challenges included slopes in excess of 8 percent; portions of the site had no access to existing storm sewer pipes; a snowmelt system had to be incorporated into the design at building thresholds; and water could not migrate into the subgrade within 10 feet of the face of the building," Evans said. "The design team proposed using permeable pavers to meet all of these criteria. The school needed to be reassured the pavers would meet all of the potential traffic loads, and be durable enough to hold up to de-icers and snow plows.

"The provision of product data, other project references and site visits, along with meetings with the design team and paver reps, provided the assurances the school needed to proceed with permeable pavers. Selection of a contractor with sufficient experience and credentials was critical to the project success, since a number of installation challenges had to be addressed in the field for a satisfactory outcome."

The building architect and project designer created a patterned paver design, with charcoal bands in a tan field laid in a herringbone style. At the main intersection of walkways, an existing traffic circle was "pedestrianized" to earn a LEED Heat Island credit. Lighter colored pavers were selected for some of the paver bands in the radial pattern.

From Silver To Gold
While the goal was LEED Silver, with the addition of a permeable paver system, Brown Hall achieved LEED Gold certification. "The building addition and site was LEED registered," Evans said, "and the paving system helped obtain the heat island effect and storm water credits."

The paver colors were selected to meet solar reflectance values allowing the project to achieve the LEED credit SSc7.1 - Heat Island Effect/Non-roof. Other LEED credits the paver system contributed to included Stormwater Management Quantity Control Credit 6.1; Stormwater Management Quality Control Credit 6.2; Regional Materials Credit 5.

The pavement system was designed for partial and full infiltration, and in places adjacent to the building a liner was included at the bottom of the profile to protect the building foundation from surface water infiltration. An electric snowmelt system was incorporated into the paver design at building entrances.

The project also received an HNA Hardscape Award for the Concrete Paver – Commercial/Industrial
Permeable category. The HNA Hardscape Project Awards are produced by the Interlocking Concrete Pavement Institute, and supported by the National Concrete Masonry Association and the Brick Industry Association.