Knock It Down, Build It Again
By Parviz Izadjoo, James R. Schneider, and Ahmet Demiroglu
The original maintenance yard facility, located in Rock Creek Regional Park in Derwood, Md., was built in the 1960s and served the park for decades. However, over time, the facility had deteriorated and needed to be updated and expanded to better meet the current needs of the department.
According to Montgomery County regulations, all new county facilities must meet basic sustainability requirements. The Maryland-National Capital Park & Planning Commission (M-NCPPC) chose to aim higher and pursue the Leadership in Energy and Environmental Design (LEED) Gold Certification for this project.
Environmental Impact—A Major Challenge
Integrating a new maintenance facility into a park setting, particularly in a regional park, without significantly impacting the environment is a major challenge. Except for the developed areas, the park is densely covered with tree canopies and understory plants. Building the facility anywhere in this park would require cutting down hundreds of mature trees and significantly increasing the area of impervious surfaces. In addition to the environmental impact and cost, obtaining approval on forest conservation plans and stormwater-management permits were major challenges.
The best way to address these challenges was to demolish the facility and build the new one within the existing footprint. This was only feasible if the existing facility could be closed or moved to another location during construction. Since the former was not possible, different operations were relocated to temporary sites. As a result, the new buildings were designed to sit on the old buildings’ footprints as closely as possible, and therefore minimized forest removal and other environmental impacts.
Water For Fire Suppression—Another Serious Challenge
The existing source of water was a well that had been abandoned for years due to possible contamination. In order to obtain a building permit, 600 yards of an 8-inch water line was brought from the adjacent community to the site. This line had to cross two high-pressure gas lines and one stream. The only way the gas company would permit that was to encase the 8-inch water line in a 5-foot diameter, reinforced concrete filled with grout. Unfortunately, cost and time were prohibitive; therefore, two alternative solutions were discussed. The first was to pump water from the adjacent Needwood Lake. This was not acceptable to the fire marshal due to the elevation of the site, which was more than 30 feet higher than the lake. The second alternative was to place a 30,000-gallon tank underground near the building and connect it to an adjacent fire hydrant. In case of fire, the fire truck would pump the water from the tank to suppress the fire. This solution saved not only months of work but also about $500,000 in construction costs.
Building Design
The new maintenance facility consists of the following buildings: administration, vehicle maintenance, equipment storage, shops, material storage, and a fuel island. The administration building serves as the entrance and is the only building open to the public; therefore, its treatment was more extensive than in the other buildings. The main objectives in the design were to create buildings that were aesthetically pleasing, durable, and low maintenance, and to use sustainable features.
The construction types for the buildings were carefully studied to strike a balance between lowering the cost of construction with the higher costs of high-performance buildings. Therefore, it was decided that all buildings except for administration would be pre-engineered with rigid steel frames and metal roofs. This decision provided economic benefit to the overall project budget. However, the lower portions of these building are ground-faced CMU to match the materials used in the administration building.
The administration building is designed as a masonry-clad, two-story structure, set into the steep slope adjacent to a specimen oak tree. It is brick on the upper level and ground-face CMU on the lower level. The roof is reflective metal that has a raised portion allowing natural light to enter the building for the multi-purpose room and office areas. This building was designed to be a “stick-built” construction.
Sustainable Design Features
The administration building—the focal point of the facility—was designed to receive LEED Gold certification. The key objective of LEED is to use sustainable measures in design and to minimize the carbon footprint. Following are some of the sustainable features implemented in this building:
Rainwater harvesting collects and filters rainwater from the roof and uses it to flush toilets. This—in combination with water-conserving, high-efficiency fixtures, and motion sensors—has reduced consumption of potable water by at least 47 percent.
Ground-source heat pump uses the earth’s constant temperature through heat exchangers, which greatly reduces the energy required to heat and cool the building.
Photovoltaic panels on roof capture the sun’s energy and converts it into electricity to power lights and equipment in the building. There are 18 photovoltaic panels that generate electricity and subsidize 15 percent of the total energy costs.
Solar water heater—Solar panels on the roof heat circulated water and store it for use in toilets and locker rooms. A conventional heater is also provided as back up.
Recycled and regional materials—Twenty-three percent of the total building materials’ content by value has been manufactured with recycled materials. Also, 45 percent of the total building materials’ value has been manufactured within 500 miles of the project site.
Renewable construction materials—Ninety-two percent of the total wood-based building materials is certified by Forest Stewardship Council.
Energy performance optimization—The building was constructed based on solar-angle optimization. A well-insulated building envelope with use of energy-efficient windows, doors, and window shades are very effective in optimizing energy performance. These techniques together contribute to an overall savings of 31.97 percent of energy costs at the maintenance yard.
Key Guidelines For A Sustainable Design
In preparing a sustainable design for the Rock Creek Maintenance Yard, a holistic approach took various components into consideration:
Function
Occupants’ health and comfort
Environmental impact
Carbon footprint
Lifecycle cost.
It is crucial that both design and construction teams have an experienced sustainability person to handle pertinent items.
The sustainability items must be identified at an early stage of design and must be suitable for a particular project and site. Choosing the sustainable solutions that are local and cost-effective is the best approach. The construction cost in general is about 10 to 15 percent higher for any LEED buildings. It is important to note that sustainable items with a long pay-back time might not be feasible.
Parviz Izadjoo, Ph.D., RLA, is a Project Manager for the Maryland National Park & Planning Commission in Gaithersburg, Md. Reach him at (301) 670-8037, or parviz.izadjoo@montgomeryparks.org.
James R. Schneider, RA, NCARB, is a Project Manager at Gannett Fleming, Inc., in Baltimore, Md. Reach him at (443) 348-2017.
Ahmet Demiroglu, RA, LEED AP BD+C, is a Project Architect at Gannett Fleming, Inc., in Baltimore Md. Reach him at (443) 348-2017.