Page 238 - Solar Power in Building Design The Engineer's Complete Design Resource

208 LEED—LEADERSHIP IN ENERGY AND ENVIRONMENTAL DESIGN

Average gas load density: [(11.85 kBtu/ft -yr × 16,773 ft ) + (5.33 kBtu/ft -yr ×
2
2
2
2
2
2
2
2
29,308 ft ) + (8.63 kBtu/ft -yr × 4248 ft ) + (32.33 kBtu/ft -yr × 1748 ft ) + (0.53
2
2
2
2
2
kBtu/ft -yr × 1726 ft ) + (6.99 kBtu/ft -yr × 4248)]/58,051 ft = 8.24 kBtu/ft -yr
California default natural gas cost: $0.00843/kBtu (taken from EIA 2003
Commercial Sector Average Energy Costs by State, Table 5: Default Energy Costs
by State).
2
2
Total natural gas cost: 8.24 kBtu/ft -yr × 58,051 ft × $0.00843/kBtu = $4032.40/yr
Total energy cost (Buildings 1, 2, 3, 4, 5, 8): $846,611.55/yr + $4032.40/yr =
$850,643.95/yr
Renewable energy cost contribution: $0.43/kWh × 930,750 kWh/yr =
$400,222.50/yr
PV offset: $400,222.50/$850,643.95 = 0.47 or 47% which corresponds to 3 points.
Hearst Tower

Hearst Tower is the first building to receive a gold LEED certification from the U.S.
Green Building Council. This towering architectural monument is located in
New York around 57th Street and Eighth Avenue. The site was originally built in the
1920s and was a six-story office structure that served as the Hearst Corporation’s
headquarters. Construction began in 1927 and was completed in 1928 at a cost of
$2 million.
The original architecture consisted of a four-story building, set back above a two-
story base. Its design consisted of columns and allegorical figures representing music,
art, commerce, and industry. As it was an important heritage monument, in 1988 the
building was designated as a landmark site by the New York Landmarks Preservation
Commission.

ARCHITECTURE
In 2001 the Hearst organization commissioned Foster and Partners, Architects, and
Cantor Seinuk, Structural Engineers, to design a new headquarters at the site of the
existing building. The new headquarters is a 46-story, 600-ft-tall office tower with an
2
area of 856,000 ft . One of the unique features of the architectural design was the
requirement to preserve the six-story historical landmark facade. The old building had
a 200- by 200-ft horseshoe-shaped footprint, which was totally excavated while keep-
ing the landmark facade.
The new architectural design concept called for a tower with a 160- by 120-ft foot-
print. To maintain the historical facade, the design also called for a seven-story-high
interior atrium.
The structural design utilizes a composite steel and concrete floor with a 40-ft inte-
rior column-free span for open office planning. The tower has been designed with two