The document describes an office building in Cologne, Germany that received a DGNB Gold certification for its sustainable features. It is a 3-story square building with an atrium for natural ventilation and light. Sustainable features include a photovoltaic system, solar hot water, rainwater collection, high insulation, ground source heat pump, and natural ventilation with heat recovery. The building uses 70% less primary energy than conventional buildings and has a heating demand less than 10kWh/m2/year.

1. Certified with DGNB GOLD label 01/09 ENERGY | HCU REAP DGNB | GOLD CERTIFIED OFFICE BUILDING

2. ENERGY | HCU REAP DGNB | GOLD CERTIFIED OFFICE BUILDING

3. Econcern Headquarter Köln (2009) ENERGY | HCU REAP DGNB | GOLD CERTIFIED OFFICE BUILDING

4. Etrium = Energy efficiency + atrium ENERGY | HCU REAP DGNB | GOLD CERTIFIED OFFICE BUILDING

5. Atrium for heating, ventilation and light ENERGY | HCU REAP DGNB | GOLD CERTIFIED OFFICE BUILDING

7. Square shaped (38m x 38m). Excellent facade/volume ratio.

8. High daylight coeff for natural light.N ENERGY | HCU REAP DGNB | GOLD CERTIFIED OFFICE BUILDING

10. 3750m effective area.

11. Room for 150 employees.ENERGY | HCU REAP DGNB | GOLD CERTIFIED OFFICE BUILDING

12. ENERGY | HCU REAP DGNB | GOLD CERTIFIED OFFICE BUILDING

13. photo voltaic system: 32,4 kW = 30.000 kWh/a ENERGY | HCU REAP DGNB | GOLD CERTIFIED OFFICE BUILDING

14. Solar thermal water for domestic use ENERGY | HCU REAP DGNB | GOLD CERTIFIED OFFICE BUILDING

15. Rain water reservoir to flush toilets etc ENERGY | HCU REAP DGNB | GOLD CERTIFIED OFFICE BUILDING

16. Cross ventilation Heat exchanger to recycle heat energy of used air. 95% efficient heat recovery ENERGY | HCU REAP DGNB | GOLD CERTIFIED OFFICE BUILDING

17. Cross ventilation Heat exchanger to recycle heat energy of used air. 95% efficient heat recovery concretecool ENERGY | HCU REAP DGNB | GOLD CERTIFIED OFFICE BUILDING

18. 48kW groundwater heat pump ENERGY | HCU REAP DGNB | GOLD CERTIFIED OFFICE BUILDING

19. winter summer ENERGY | HCU REAP DGNB | GOLD CERTIFIED OFFICE BUILDING

20. PHPP approved Primary energy: 116 kWh/m2/a 70% < than conventional office buildings Heating: < 10kWh/m2/a 1L oil/ m2/a (5 times less) ENERGY | HCU REAP DGNB | GOLD CERTIFIED OFFICE BUILDING

21. ENERGY | HCU REAP LEED | GOLD CERTIFIED OFFICE BUILDING

22. BofA Tower, NYC Cook Fox, 2009 LEED PLATINUM certified ENERGY | HCU REAP LEED | GOLD CERTIFIED OFFICE BUILDING

23. BofA Tower, NYC Cook Fox, 2009 LEED PLATINUM certified ENERGY | HCU REAP LEED | GOLD CERTIFIED OFFICE BUILDING

24. If you don't build green, you're building obsolete," Douglas Durst, Developer BofA Tower Building Introduction video ENERGY | HCU REAP LEED | GOLD CERTIFIED OFFICE BUILDING

26. to optimize daylight transmission to street level.ENERGY | HCU REAP LEED | GOLD CERTIFIED OFFICE BUILDING

27. natural elements relate to human scale of the street. ENERGY | HCU REAP LEED | GOLD CERTIFIED OFFICE BUILDING

29. glass inner walls, so that even people stationed near the core of the building will be able to look outside.ENERGY | HCU REAP LEED | GOLD CERTIFIED OFFICE BUILDING

30. The mixture used in the tower concrete is 55% cement and 45% slag( a byproduct of blast furnaces). The use of slag cement reduces damage to the environment (One ton of cement produced emits about one ton of carbon dioxide into the atmosphere.) ENERGY | HCU REAP LEED | GOLD CERTIFIED OFFICE BUILDING

31. Rain water collection combine roof-captured rainwater with the grey water from the building's washroom sinks, condensation from the tower's air conditioning and from the steam purchased from the utility company ConEdison used to flush the toilets and run evaporation panels that help cool the building. Rain water collection ENERGY | HCU REAP DGNB | GOLD CERTIFIED OFFICE BUILDING

33. Thermostat for each office (room) for individual regulationENERGY | HCU REAP LEED | GOLD CERTIFIED OFFICE BUILDING

34. air filter for NYC "We will take in four times as much air as New York codes require, and the air we expel will be much cleaner than what we take in." The greater volumes of air make it possible to flush more VOCs (volatile organic compounds) out of the air, diminishing the likelihood of "sick building syndrome" sometimes blamed on imperfect air filtration systems. He says that people working in the Bank of America Tower will breathe air cleaned of 95 percent of its particulate matter instead of the 35 percent typical in office buildings. ENERGY | HCU REAP LEED | GOLD CERTIFIED OFFICE BUILDING

35. “Cogeneration (also combined heat and power, CHP) is the use of a heat engine or a power station to simultaneously generate both electricity and useful heat(…). By-product heat at moderate temperatures (212-356°F/100-180°C) can also be used in absorption chillers for cooling” (source: wikipedia.org). Cogeneration A 4.6-megawatt fuel-cell cogeneration plant provides part of the base-load energy requirements. ENERGY | HCU REAP LEED | GOLD CERTIFIED OFFICE BUILDING

37. 2 to 3% for environmental factors.

38. Payback within four years through saved energy expenses.

39. The building is built to environmental codes believed to be in place in future years, eliminating the need for costly modifications.ENERGY | HCU REAP LEED | GOLD CERTIFIED OFFICE BUILDING