Sustainable:

Facade: shading, wind flows, wind protector

Special care is to achieve optimized environmental conditions with a minimized energy demands in three steps: Reducing the energy and meeting remaining conditions with high-performance building-integrated systems and sourcing those systems as much as possible with renewable sources.

One of the core ideas of the sustainability concept is to heat and cool working, living and hotel room areas and use the exhaust air of these offices/rooms to condition the atrium, which is used as a big buffer space. The external facades will feature a high performance with adaptable external shading device to reduce solar gains in summer. The concrete slab imbedded pipe system provides cooling without draft problems and in winter comfortable radiant heating. In summer the cooling of the offices/room spaces will be achieved for major amount of time just using the slab system. The decentralized ventilation units vent fresh air into the rooms and serve as peak time cooling in summer. During winter the fresh air will be heated inside the units and distributed into the rooms using the displacement ventilation principle. An overflow to the atrium allows the exhaust air to flow from the offices into the atrium and through louvers in the roof to the outside.

The atrium itself is a buffer space, which is naturally ventilated and heated/cooled by the exhaust air from the rooms and offices. This means the temperature in the atrium will swing from 15°°C in winter to ambient conditions at the upper levels in summer (temperature stratification). To minimize the peak summer conditions, features inside the atrium like the water wall and floor cooling system will condition this space in addition. The water wall is used for cooling and dehumidification purposes in summer, whereas in winter the water will evaporate and humidify the air. Special areas inside the atrium will get this "own” climate. Especially for a front desk this local climate is important to guarantee adequate working conditions.

The energy supply system is based on natural resources like river water heat exchanger to provide cooling in summer as well as heating - in combination with a heat pump - in winter. Photovoltaic cells integrated in the atrium roof generate power.

Another objective of a sustainable building approach thrives to minimize of energy intensive materials instead local available, sustainable materials will be used.

Structural system

The main driver when choosing a suitable structural system for the building was safety during earthquakes, since the city of Yerevan is situated in a region prone to strong earthquakes, and flexibility of space. Therefore the vertical structure, which resists gravity load and forces resulting from earthquake action, was rationalized to reinforced concrete cores and composite columns. While two cores on the inner perimeter of the taller tower are required to ensure structural stability, one is sufficient in case of the lower one. At the base the outer walls of the cores are 160cm thick. Three concentric sets of composite columns (steel tubes filled with concrete) are foreseen. Due to the terraced shape of the building the columns on the outermost perimeter are inclined towards the centre of the building. Those on the innermost perimeter are inclined in 3D space to form a mesh. All columns have a maximum diameter of 130cm. The core wall thickness and column dimensions are reduced with the height of the building. Structural facade skin will be used to support the gravity load of the slabs. Fire safety of steel components will be provided by a special coating which guarantees up to 90 minutes of protection. Inter-storey slabs are post-tensioned using unbounded tendons and have no drops or girders, except in the region where extremely large spans are foreseen. Their thickness is estimated to 25cm to 30cm, depending on the span. The maximum length of cantilevers may be 3m to 4m. Due to landscaping and weight of vehicles used during interventions the slab above first basement is 40cm thick. Based on the available data a 200m deep foundation slab will be sufficient below the cores of the taller tower. Strip and pad foundations are foreseen below the columns.
Design peak ground acceleration during earthquakes was determined based on the data available in Global Seismic Hazard Assessment Program. Subsequent investigationsIn the subsequent design phases a geodetic report and a detailed report on soil conditions will be required, including any restrictions regarding foundation depth. Additionally, a retaining wall for protection of the excavation will have to be designed.

Main project data:

Surface Area:

Base:

Floor +0: 7.385m2

Shopping: 3.345m2

Hotel lobby: 374m2

Exhibition: 2.215m2

Restaurant, bar: 1.450m2

(Summa Base: Floor 0 + 1 (mezzanine): Shopping and services: 14.770m2)

Tower A:

Business (6floors (from +2 to +6): Summa: 12.520m2

Ballroom and conference rooms (7^th floor): Summa: 2.150m2

Hotel rooms – (12 floors (from +8 to+19)): Summa: 19.125m2

Hotel facilities SPA, pool, panorama restaurant, fitness: (3 floors (from +20 to +22): Summa: 2.820m2

Tower B:
Residential: Summa 5.745m2
Base+Tower A + Tower B: above +0m: 57.130m2

Garage (2floors (from -1 to -2)): Summa: 25.000m2

Construction price:

72 mio USD for floors above ground

10 mio USD for floors under ground

Other data:

No. of underground parking: 1.000 parking spaces

No of residential flats: 36 units

No of hotel rooms: 200

Maximum height: 96,5m

Tower A: 96,5m

Tower B: 36m