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Architect- Ton Alberts (Alberts and Van Huut). Completion Date: 1987. Building Use Summary: Five to six story commercial building. Number of Occupants: 2,500 (Designed for 1,800). Gross Floor Area: 50,000 square meters. Ventilation Strategy: Air-conditioning (primary). Former use of many green design features.
Tour given on August 8th by A.J.M. Kruijt, a general building manager employed by ING Bank.
There is an interesting story behind ING Bank Headquarters. The building was very different from others that existed at the time when it first opened in 1986. The building was originally designed to use natural ventilation, as well as other holistic approaches well integrated with the building. The 540,000-square-foot headquarters of the country's second-largest bank, previously known as Nederlandsche Middenstandsbank (NMB), is often considered one of the most remarkable buildings in the world. In the following discussion, we consider the building as it was used prior to 1992.
It is largely day lit, highly energy efficient, and architecturally innovative. Many of the organic features and unusual building geometries were drawn from the teachings of Austrian philosopher Rudolph Steiner, whose ideas would hardly be expected to be found in a commercial office space. The building, a a series of interconnected towers did not use conventional air conditioning—something unheard of for a building of this size at the time of its opening.
The building originally relied on passive natural ventilation for cooling with the use of some back-up absorption chillers. The building used less than a tenth the energy of its predecessor and a fifth that of a conventional new office building in Amsterdam. The annual energy savings were approximately $2.9 million (1996 U.S. dollars) from features that added roughly $700,000 to the construction cost of the building. The additional investment was paid back in only three months.
It is interesting to study how the building came about. In 1978, the bank was the fourth-largest bank in the Netherlands. According to Dr. Tie Liebe, who managed the bank’s real subsidiary; the bank was viewed as "stodgy, and too conservative." When ING outgrew it’s existing headquarters in the late 70s, it was decided that a new headquarters building would be constructed to create a new image for the bank. The ultimate goal was to create a functional yet cost-effective new headquarters that would be both appealing and environmentally responsive in design and function.
The ING board of directors stated a very strong vision for the building. They dictated that it would be “organic” and would integrate "art, natural materials, sunlight, green plants, energy conservation, low noise, and water." Over a three-year design period involving energy experts, architects, artists, and building engineers came up with three very specific requirements. First, the building was to be built using the latest technology, including a specially designed security system and options for individual climate control. Second, the building had to be flexible, able to respond to inevitable changes in space needs over time. Third, the building had to be energy efficient, yet not cost "one gilder more" than conventional construction. If we were to look at the building prior to the addition of air-conditioning, the ING building satisfied all three of the requirements stated above.
By natural convection, warm stale air from interior spaces rose up into the five to six story towers of the building. This air was channeled with the aid of some fans through a recovery wheel (Airwheel 2 by Holland Heating). Fresh outside air was typically pre-heated by solar panels, as well as by the warm stale air passing through the recovery wheel. The warmed fresh air was subsequently channeled back to occupied office space. When temperatures rose too much, absorption chillers were used. The chillers made use of excess heat from on-site gas turbine generators. Upon first impressions, it is not apparent that the building layout was planned the way it was to minimize exterior noise. With the use operable windows, noise infiltration must always be considered.
Unfortunately, natural ventilation is no longer used because of a higher than designed for occupancy level and the increasing amount of heat generated by today’s computers. Air conditioning was installed in 1992. Windows are no longer operable, thus eliminating the use of nighttime cooling. In the past, night cooling proved effective due to the significant amount of exposed concrete in the building, as well as the result of average night-time temperatures around 17 °C.
The building was designed to accommodate 1,800 people. There are now 2,500 people in the building. Upper-level management will be moved to a new building in a couple years. Due to increased demand, there are three generators (80% efficiency) each capable of output of 1800 kW. The power requirement for the building is 2.5 MW. Currently, some electricity must be purchased from a power company. The original A/C system operated when the outside temperature rose above 27 °C. Now when the outside temperature is above 18 °C, a supplemental centrifugal chiller is turned on, ready for use. In addition to ventilation systems, the building management system is able to control lighting, blinds, and atrium skylights. Several weather stations serve as input to the BMS.
Building managers at ING headquarters would like to go back to using the building in the manner it was originally designed for. Currently, three things are being looked out to move in that direction: 1) moving 700 people out of the building; 2) Investing in flat panel LCD displays to minimize heat loads; 3) purchasing extra generator sets, so electricity does not need to be purchased from a power company (up to 25% is now purchased). The first requirement will be implemented within the next few years. A new building has been designed, with construction in its early stages as of August 2000.
Reference Picture 55.A formally operable stairwell skylight. The window panel on the upper left can be slid open on tracks. The windows on the middle left can be opened to vent smoke from a fire.Photo courtesy of ING Bank.
Reference Picture 56. ING Bank Headquarters. This aerial shot reveals how expansive the complex is. Skylights are featured in each section of the building. These skylights used to be opened to provide stack ventilation. Picture Courtesy of ING Bank.
Reference Picture 57. One of several atriums in the ING Castle. The windows were operable when the building was naturally ventilated. Note the significant amount of plant life, as well as the substantial amount of exposed mass. Picture Courtesy of ING Bank.