Citadel Construction completes two LEED stunners.

Citadel Construction Corp., ranked as one of New York's top 25 construction companies, is also gaining recognition as a leader in sustainable construction and design.

Citadel recently completed two stunning new headquarters, one for the National Audubon Society and the other for WSP Flack + Kurtz, both soon to be certified LEED Platinum and Gold respectively. David Cooper, CEO/President of WSP Flack + Kurtz, praised Citadel's work on projects, saying, "We are very proud of our new headquarters and our staff loves the new space. After working closely with Citadel and FXFOWLE on the LEED Platinum headquarters for the National Audubon Society, we knew we had the right team to deliver a Gold rated sustainable home for us."

National Audubon Society

The new 27,000 sf headquarters of the National Audubon Society sets a new standard of excellence, creating an exemplary green space that works in harmony with its urban environment. Occupying the seventh floor of 225 Varick Street, the renovated space is expected to far exceed the criteria for a Platinum LEED Commercial Interior (CI), as outlined by the US Green Building Council (USGBC), making it one of the greenest CIs in the world.

The Citadel team created an HVAC system that eliminated overhead ductwork, retaining the space's airy, loft-like feel. A constructed raised floor facilitates the distribution of hot and cool air through over 200 individual outlets that allow employees to adjust the temperature of their immediate environment. The gas-powered heating and cooling systems emit no chlorofluorocarbons and operate independently of the other floors. The project team also installed a new cooling tower which was hoisted to the roof, new supply and return risers for the HVAC, and an upgrade of the existing service to the floor.

Citadel used only low VOC substances in construction and sustainable, recyclable or reclaimed materials to build and furnish the offices. Floors are bare concrete treated with a sealant or natural cork; countertops are made from compressed paper products or recycled glass. Most project wood was either salvaged or certified by the Forest Stewardship Council (FSC). Construction waste and debris were sent to a specialized recycling plant. To reduce transportation costs and minimize pollution, products came from within a 500mile radius of the Hudson Square address.

The rectangular space is designed around a central core, with abundant light flowing through full-height windows, skylights and an open office layout. A spacious five-foot-wide corridor offers access to the windows and views of the cityscape and sky. Partitions between offices are glass panels with aluminum trim that can be removed and reconfigured; polypropylene panels between workstations slide easily.

Energy efficiency is optimized through fluorescent pendants that use a daylight harvesting system which automatically adjusts illumination levels according to the amount of natural light available and with indirect lighting fixtures and low wattage bulbs.

To ensure indoor air quality, Citadel insulated the walls at a level three times the energy code. Double-paned windows act as 'heat mirror' sheets, and high-speed air flow guarantees a plentiful supply of purified air.

WSP Flack + Kurtz

The new 40,000 sf headquarters for WSP Flack + Kurtz, located at 512 Seventh Avenue, was built on a fast-track schedule that succeeded in the seamless relocation of 250 employees.

A thorough IAQ (Internal Air Quality) Plan detailed several initiatives; all ductwork was sealed airtight on supply and return ends during transport and delivery; a temporary site ventilation system reduced odors. Plastic shields and footpaths segregated work areas minimizing dust and debris throughout construction and helped maintain a clean environment and healthier, more breathable air. To ensure at least three-quarters of all construction debris was specially handled and hauled away for processing and reuse, Citadel hired a specialty recycling subcontractor to implement a waste management plan.

To realize the striking design, the project team mounted a pair of 500+ pound millwork sliding doors on custom-made hardware imported from Germany, then suspended four 10 ft. high Lucite panels and a global graphic pinpointing WSP Flack + Kurtz's worldwide sites using high-intensity aircraft cable.

Citadel Project Executive Ronald Welsh, LEED AP, says, "Citadel's forward-thinking approach is placing us at the forefront of green construction. We recognize that evaluating a project's direct impact on the environment is no longer enough; every project must be viewed with respect to its potential effect on the urban biodiversity of the future."

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