Energy Efficient Glass Structure - European Investment Bank Headquarters

The winner of the first place in the Emilio Ambasz Prize for Green Architecture for International Buildings this year was European Investment Bank in Luxembourg. This truly iconic building was designed by Ingenhoven Architects.

This extensively glazed building is famed for its unique structural design, apart from several energy-efficient design elements. By virtue of these qualities, this office building achieved the coveted “Very Good” rating under the United Kingdom’s Building Research Establishment Environmental Assessment Method (BREEAM). It is also the first building on continental Europe to have been assessed under this scheme.

The headquarters of the EIB boast of a 170 meter-long tubular glass and steel structure with a zigzagging non-hierarchical office layout. This 72,500 sq meter building has enough office space and facilities for 750 employees and includes indoor ‘warm’ atria, a cafeteria, restaurant, and a connection to nearby buildings.

The building is completely shielded by 13,000 sq meters of glass that allow the penetration of daylight easily from all angles. Operable windows allow occupants to directly control the room temperature and permit natural ventilation.

Glass Roof

The highlighted tubular glass roof, framed with light-weight steel, covers 170m by 50m of building area. Being glazed, the roof offers maximum daylight and transparency and is key to the building’s environment-friendly concept as it curves around the office floor plates. The tubular glass envelope allows for daylighting of the working bays. The transparency of the external envelope is reflected internally by an open office layout that promotes free interaction.

This glass roof curves around the floor plates to create atriums in the V-shaped “gaps” of the building wings. The landscaped winter gardens on the side of the valley are unheated and act as climate buffers; they reduce variations between the outside temperature and the desired temperature in the offices, thereby contributing to lowering heating requirements in winter and cooling requirements in summer.

In contrast, the atriums on the boulevard side serve as circulation spaces. The largest atrium houses the main entrance to the building, and so temperatures in these areas have to be kept at a comfortable level. Both winter gardens and “warm” atriums are naturally ventilated through open flaps in the shell to draw fresh air into the building and to reduce heat gain especially in the summer months.

Cold water pipes also run through the concrete floor slabs, creating chilled ceilings in order to cool the building in summer and to regulate the building temperature between seasons. In winter, thermal energy from solar heat gain is used to heat the building, thus reducing energy consumption.

Energy Conservation

Mechanical systems such as lighting, sun shading, heating, cooling and ventilation can be controlled individually. Wastage is avoided as much as possible, as individual settings are reset to the most efficient levels possible several times a day by the central control unit. Staff members can open their windows to the atriums and winter gardens or to the outside at almost all times.

All offices are equipped with a control panel that allows building users to individually regulate blinds for sun shading, lighting and temperature. Artificial office lighting is restricted to 300 Lux throughout the offices. However, staff can illuminate their individual work spaces with desk lamps to 500 Lux. This overall reduction in general lighting Lux levels significantly reduces the building’s energy consumption.

All surfaces - walls, floors and ceilings - are also designed to make optimum use of daylight, enhance luminosity and thus contribute to a pleasant working atmosphere.

Efficient Construction Materials

Construction materials were selected in accordance with the energy used for their manufacture, with materials with the least energy consumption given preference. The internal façade frames, for example, which cover a surface area of 17,600m2, are made of wood rather than aluminium because research found that the energy used in the manufacture of the wooden materials is only 2% of that which would have been expended in the manufacture of the equivalent aluminium profiles.

This environmental philosophy extended to the construction site, where the majority of materials were chosen for their small environmental impact. For example, all wood used has been certified by the FSC or the PEFC (programme for the endorsement of forest certification).

Elegant Glazing of Capital Gate Tower

Abu Dhabi will be home to one of the world's great buildings - Capital Gate, an iconic and avant-garde building that blends the beauty of the wave with the power of technical advancement.

Abu Dhabi National Exhibitions Company (ADNEC) has revealed that glazing work on the iconic Capital Gate Tower, currently under construction next to Abu Dhabi National Exhibition Centre, is almost complete. This “Capital Gate” has been designed by the New York firm RMJM architects.

Capital Gate forms the focal point of Capital Centre, the business and residential micro city being developed by ADNEC around the thriving Abu Dhabi National Exhibition Centre. When fully complete, Capital Gate will feature the 5-star hotel - 'Hyatt at Capital Centre' besides playing host to some of the most exclusive office space in the UAE capital. The Capital Gate is a 160m-tall leaning tower in Abu Dhabi, UAE.

The architecture of the Capital Gate tower is dotted with monster glass panels. Monster glass panels for Abu Dhabi’s 'leaning tower' development have arrived on what the project team claims is the world’s biggest flat bed truck. The panels are for the Capital Gate building, which architect RMJM recently submitted for the Guinness Book of Records as the ‘world’s most inclined building’. It has a tilt of 18 degrees – over four times more than the Italy’s Leaning Tower of Pisa.

More than 12,500 individually shaped glass panels have been installed on Capital Gate's façade in a complex engineering feat which has taken ADNEC and its construction partners ten months to complete. In an intricate operation, 728custom-made glass panels have been used. Each pane of glass had to be a slightly different shape and fitted at a different angle due to the building's unique lean and its curved profile. The first two glazing panels are weighing approximately 5 tonnes each.

The tower's unique shape and character made the installation of the glazing particularly challenging for our engineers. It is a compliment to all involved that the installation took place during ADNEC's busiest year ever for exhibitions and events; yet, there was no disruption to the visitors or exhibitors.

The glass panes on Capital Gate make up more than 700 larger glass "diamonds," and were manufactured in the United Sates with the steel frames holding the glass precision-cut in Austria before being shipped to the UAE. ADNEC stored the glass panels away from the construction site and delivered them as needed, on enormous flatbed trucks. Once they reached the Capital Gate construction site they were meticulously placed into the correct position by on-site engineers.

The RMJM project team is using the glass to create a new kind of glazing system called ‘Cardinal C240’, which is anti-glare but also highly transparency. The glass used is a highly energy-efficient and low 'e' category glass. This glass has two silver coatings which minimise glare and maximise light transmission. The double glazed façade will allow natural daylight into the building while boosting energy efficiency and shielding users from harmful glare.The use of this advanced variety of glass is a 'first' for the UAE. The 'pressure-plate' system that has been developed for the steel frame which holds each pane in place guarantees the water tightness of the façade and allows thinner panes of glass to be used, thereby reducing the weight of the glazing system.

The lean and curve of the building added considerable complexity to the glazing process. A few glass panes have deliberately been left out to ensure that adequate ventilation exists prior to the installation of the air conditioning.

Due to its unique shape, Capital Gate is being constructed on top of a concrete raft with a dense mesh of reinforced steel. The steel Diagrid sits above an extensive distribution of 490 piles that have been drilled 30m underground to accommodate the gravitational and wind loads. The angles and dimensions of the building facade have been meticulously designed to ensure that each individually shaped panel accurately defines the shape of this magnificent structure.