Diseño del estudio de caso

has a “health book” that specifies the composition and location of all building materials. Photo: Jacques Le Goff. Courtesy of Ademe.

TABLE 7.25

Energy use, 2007a

Annual use Intensity

HVAC 1,295,238 kWh 130 kWh/sq m

Lighting 202,299 20

Individual electrical 360,389 36

sockets (plug loads)

Miscellaneous 418,286 42

Total 2,276,210 kWh 228 kWh/sq m

Note: Miscellaneous includes the consumption of 900 sq m of shops and a restaurant on the ground floor, elevators, parking garage and façade lighting and small equipment.

a Frank Hovorka 2008, “Coloring Paris”, High Performing Buildings, Summer, 2010. www.hpbmagazine.com/images/stories/articles/coloring %20Paris%20Nights.pdf (accessed November 9, 2011).

At a glance Name: EMGP 270

Location: Aubervilliers, France Completed: June 2005

Size: 107,639 sq ft (10,000 sq m) Cost: €16.2 million ($24.9 million) Distinction: HQE Office

Program: Commercial office building

Project team

Owner: ICADE/EMGP Architect: Brenac & Gonzales Project Manager: Meunier

Mechanical Engineer: Igeni, Thor Engineering Structural Engineer: SCYNA 4

FEDERAL ENVIRONMENTAL AGENCY, Dessau

The Federal Environmental Agency (Umweltbundesamt) in Dessau does not resemble a typical government office building. The exterior is clad with polychromatic panels, while its serpent shape loops back on itself to surround a covered atrium. Completed in May 2005, this 428,263- sq-ft (39,800-sq-m) building is not only architecturally unique; it’s also one of the highest performing office buildings in Germany.

Iconic buildings are not unprecedented in Dessau. The legendary Bauhaus was built there in 1925–1926 after it moved from Weimar. The Bauhaus remains an international icon of design and technology.33

After the city was destroyed during World War II, most of Dessau was rebuilt in the concrete-slab style typical of the time and went on to become an industrial city of East Germany.

Founded in 1974, the Federal Environmental Agency is Germany’s central authority on environmental matters. The Agency employs econ omists, chemists, biologists, and legal experts who work together to find solutions to environmental problems.34 _{Formerly based in}

Berlin, the Federal Environmental Agency chose Dessau for a new headquarters building in an effort to revitalize the city, then saddled with a high unemployment rate.35

Designed by Berlin-based architects Sauerbruch Hutton, the building’s façade is primarily responsible for its iconic image (see the interview in Chapter 5 with Matthias Sauerbruch). Horizontal strips of Bavarian larch wood cover the parapet and lintel areas. The glass panels between the window strips alternate between transparent and colored areas. The surrounding site inspired the colors used, with thirty-three separate shades. Nearest to the park, the panels are varying shades of green. Panels near an old brick factory, which is now the library, are dark red, lavender, and purple hues. Ochre, orange, and red-toned panels adorn the eastern façade, which faces a nineteenth-century resi - dential neighborhood. The main building includes a café, audi torium, information center, and library.36

The four-story main building consists of a 1,520-ft (460-m) long, snake-shaped loop that serves as the office wing for the Agency’s 800 employees. This floor plan reduces exterior wall space that would otherwise be exposed to the elements and favors gently curving corridors.

The ends of the loop converge at a large serrated glazed wall which serves as the main entrance. The forum, which is just behind the main

entrance, is a crescent-shaped space that links the offices and public areas together. The covered atrium, located in the center of the loop, is a neatly landscaped area. Bridges cross the atrium at three points to connect the surrounding offices. Each employee has a private office with a window and the offices facing the atrium are the most sought- after.37

The Agency wished to create an ecological building with high standards of energy efficiency and renewable resource use.38 _The

building’s sustainable strategies include geothermal heat, solar thermal collectors, PV panels, and natural ventilation. Renewable energy supplies 9 percent of the building’s energy requirements. As a result of its green measures and energy performance, the building was awarded a DGNB Gold certificate (the highest level) from the German Sustainable Building Council.39

The main building is a poured-in-place concrete frame with a flat- slab construction supported by two rows of edge columns. The exposed concrete ceiling provides thermal mass to hold heat and cold at the appropriate times of the year. The interior ceilings remain uncovered because ducts for electricity, data, and other cables are integrated into channels under the floor.40

Fitted with a glazed sawtooth roof, the atrium plays a key role in maintaining a comfortable indoor ambient temperature. During the cold months, the temperature in the atrium is about 22°F (12°C) warmer than the outdoors, which helps minimize heat loss from the offices. The atrium assists the building’s natural ventilation in the warm months.41

A 2,475-sq-ft (230-sq-m), 32-kWp PV system is integrated into the glazing of the sawtooth roof above the forum and provides sun protection as well as power for the building. An additional 4,575 sq ft (425 sq m) of PV with 68 kWp output was installed in 2010. On the roof of the main building, 2,325 sq ft (216 sq m) of vacuum-tube heat-pipe solar collectors harness solar energy to help cool the build - ing’s server room, print office, and lecture theater, via an absorption chiller.42_{The chiller cools water to around 44°F (7°C). The chilled water}

is then transferred to a series of pipes that cools air which is blown across the pipes and into the rooms.

The building is mainly heated using a geothermal heat exchanger, the building’s most significant energy-saving feature. The system contains about 5 km (three miles) of underground pipes and is the

world’s largest geothermal heat exchanger.43 _{When the outdoor}

temperature is particularly high or low, the supply air to the offices is conditioned in the earth-to-air heat exchanger. The air intake and exhaust systems for the office area include heat recovery equipment with a recovery efficiency of 74 percent.44

In winter, heat is distributed throughout the offices through panel radiators with thermostat valves. The atrium and forum are not heated or fed with supply air in winter as they are not part of the insulated building envelope.45

In lieu of air-conditioning, the building is cooled using natural 7.50 The Federal Environmental Agency headquarters in Dessau has a 110-m snake-shaped loop that reduces exterior wall space and creates gently curving corridors inside. Photo: © bitterbredt.de. Courtesy of Sauerbruch Hutton.

TABLE 7.26

Annual energy and water use, 2007–2008a

Goal Intensity (2007)b _{Intensity (2008)}c

Electricity 15.9 kWh/sq m 27.5 kWh/sq m 22.9 kWh/sq m

Cooling (electricity) 2.0 (3.9) (3.6)

Cooling (thermal) 3.5 (3.0) (7.2)

Heating 44.7 63.1 62.8

Total site end-use energy 66.1 90.6 85.7

Primary energy 82.0 113.1 99.7

a Bundesinstitut für Bau-, Stadt- und Raumforschung (BBSR), April 10, 2009, “Abschlussbericht: Part A and Part C,” 117–07–10–04–2009. b Ibid., Part C, p. 111, Table C 1.3.

7.51 With a glazed sawtooth roof,