Chilean architects, dRN Architects has submitted to ArchDaily their recent submission for the Beton Hala Waterfront project in central Belgrade, Serbia. Additional images of the proposal as well as a lengthy description of the work can be found after the break.
INTRODUCTION Our design for the BHWC building starts off by acknowledging the importance of the existing Beton Hala structure not only as a significant continuous building clinging over the riverbank, but as an urban platform from which to relate to several essential city attractions. The elongated rhythmic shape portrayed by the existing BH structure and the site itself suggests to us the use of extended horizontal volumes, which are proposed as piled ascending ramps. The building will become a new architectural landmark in Belgrade housing, in a single iconic structure, a multi-programmatic edifice and perhaps more importantly will become a dynamic hub for visitors. A superior pedestrian connection between the river front, the platform (the Park where BHWC is embedded) and the Fortress level is a decisive goal of our project.
URBAN PIECE The resulting BHWC building becomes an essential urban element; a design endeavored to connect and attract visitors and locals, over a stand-alone building. Consequently our project considers maximizing the usable public area by occupying the building’s roofs. Low-pitched volumes (6 to 8%) become a gentle connecting promenade, both a contemporary piece of the Kalemegdan Park and a building itself. This winding walkway offers unique views over the Sava River and Kosancicev Venac area, where circulating people are invited to stay and behold the scenery. The resulting elongated structure is respectful to the local context and unobtrusive to the landmarks, reinforcing the outline of the hill; a dignifying base for the Belgrade Fortress.
LOCAL IDENTITY Contemporary in appearance, the BHWC proposal considers local culture as a major motivation source, not just to blend in but to properly represent the current spirit of the city. The floorplan is designed as a continuous alternation of ‘slabs’ or volumes similar in size and proportion to the old star-like Belgrade Fortress walls, with the new building unwinding and finally ending in the lower BHWC Park. As the building is meant to be an architectural landmark, it is entirely represented and projected in white colors and materials, echoing and stressing Belgrade’s White City title.
The layout of the building has been planned keeping in mind the Belgrade’s population who enjoys the outdoors and spend a lot of time in public places throughout the year. This characteristic gives way to propose an open occupation of the ground, an outwards facing building. Restaurants, clubs, cafes, a multi-use auditorium and shops have easy and continuous access to the platform and the Beton Hala. The sole exception being The BH Gallery; the only program detached from the ground, pursuing the more silent and controlled ambiance required for such purpose. The roof ramps increase the public ground area, making
them an ideal place to relax and spend time, whilst having attractive views of the city and the Sava River. The park towards Kosancicev Venac is respectfully free of construction in an attempt to draw the attention to the city skyline, where an enhanced pedestrian communication over Karadjordjeva Street is proposed.
TRANSPORTATION NODE As a complex hub which summons diverse public and private transportation means, the project priorities the clearance of the platform, especially the river border. Strategically, this is organized as follows:
-Car garage parking (800 cars): Underground parking in levels 77 and 74. Accesses and exits from Vojvode Bojovica Boulevard and Karadjordjeva Street. Easy pedestrian access to the main lifts, stairs and ramps.
-Bus parking (15 buses): Ground parking under cantilevered BHWC building. Road access and exit from Vojvode Bojovica Boulevard. Easy pedestrian access to the main lifts and ramps.
-Tram stop: North and South bound stations on ground level, with easy pedestrian access to BHWC trough park walkways. The elevated tram rails over Vojvode Bojovica Boulevard are designed to meet local standards.
-Cruise ships passengers: Pedestrian access through BH escalators and lifts.
-Cycle tracks: Continuing the riverbank cycle paths with connection to BHWC building. The ramps consider cycle lanes to link with Kalemegdan Park and Kosancicev Venac.
-Pedestrian access: Provided from the riverbank (4) through stairs, escalators and lifts occupying ‘8 Beton Hala modules’ and from the Belgrade Fortress through the bridge over Vojvode Bojovica Boulevard. Handicapped access is provided by both lifts and gently sloped ramps. The Tower is a vertical structure in the center of the building which connects all levels (2 undergrounds, platform, restaurant, shops, Gallery and Kalemegdan Park level) by lifts and stairs. The Tower also becomes an iconic element within the building, on which a visible BHWC sign is proposed.
-Gas station: Underground station with access and exit from Vojvode Bojovica Boulevard. Located in the extreme north end of the site, with cross ventilated spaces and natural lightning.
STRUCTURE The ramping volumes are formed by 5 compact aerial steel-frame parallelepipeds. The underground and first level concrete building support the first ramp volume as it begins to ascend. The following volumes are supported by concrete hollow columns. Similar to the structure of a bridge, the aesthetically designed perimeter trusses provides structure, allowing for an open plan internal space. The steel-frame structure is clad in further insulation and finishing layers. On the facades, frost insulated glazing is mounted, and marble is installed on top of the roofs, following the Parks’ material continuous effect.
CIRCULATION SCHEME The BHWC building is served by a multifaceted alternation of internal and external ramps, as the main circulation walkway. Direct access is granted anyways in every strategic node, occupying the hollow structural columns. Inside the columns, vertical connections are planned, containing the lifts, staircase and technical shafts. Externally the floor ramps have access to specific
points of connection, specifically The Tower, the main vertical connecting node. The BHWC also considers a bridge, spanning the gap between the building and Kalemegdan Park. The promoter’s program requirements have been assigned to specific volumes, keeping a logical and strategic interrelation. Public spaces inside the building can be accessed by direct or indirect means.
SUSTAINABILITY BRIEF The design and specification of the BHWC building proposal aims to meet the most up to date sustainability benchmarks. Strategies are selected to build a Zero Carbon building in order to make of it not only a representative architectural landmark but also a model for Serbian’s current environmental agenda; a wholesome and thorough sustainable statement. In terms of benchmarks, the BHWC aims to be built to meet cutting edge energy-efficiency standards, and be BREEAM excellent (UK) /LEED platinum (US) certified, among other local requirements. In order to achieve this, Belgrade climate has been analyzed to propose the more suitable strategy. As a city with moderate continental climate, both overheating and low temperatures can be expected. Suitable strategies have to be properly selected to reduce the energy load. Based on BREEAM indicators the issues that have been addressed are:
1.1 Passive strategies; minimizing energy requirements The single, most relevant strategy is correct orientation. Our proposal organizes mostly elongated North-South volumes, leaving relatively neutral large East-West facades. This exposure contains the commerce and Gallery area, a zone which benefits from deflected sunlight. The South facing nodes are designed to host the more public areas such as The BH Gallery’s restaurant, offices and terrace which can benefit from sun exposure. On the opposite, inward facing programs such as the auditorium, clubs and the Conference Hall are strategically located at the North end. Finally the ground-level restaurants facing the Sava River have an internal space and a summer external extension with sun-shading eaves.
Natural ventilation schemes are designed to tackle overheating and provide a healthy internal environment. During the summertime, the predominant South-Eastern wind, the Košava is stronger between 5:00 and 10:00 (Glossary of Meteorology, 2010). The BHWC commerce and gallery’s potential overheating can be effectively downsized with night cooling strategies, profiting from the favorable cooler dawn wind. During the daytime, protruding eaves will deflect most of the direct sunlight, which is enhanced by cross ventilation. The commercial building is proposed as a mix-mode building.
Natural lighting is a major energy-saving measure in the project. Frost glazing on the facades provides several effects: the BHWC white appearance; translucent shades and depth effects; inverts the day-night manifestation of the building; but most importantly, provides positive internal daylight values. The depth plan is relatively narrow, proportioned to the facade height in order to provide sufficient (+300 lumens) natural light to every corner. This is reinforced by square lightwells in specific points of the building where the floorplan depth is greater than required, which is also repeated in the parking underground floors.
Superinsulation standards (Passivhaus (Germany) similar) are to be specified for the building’s fabric, having particular attention on the glazed facades, which have to comply with very low energy transmission values (max 1.2 W/m2K). Particular attention has been paid to ensure the reduction of thermal bridging to negligible values of y=0.03. The design also pays particular attention to the minimization of heat loss, ensuring air tightness levels of 1m3/h/m2.
1.2 Active strategies; energy generation Due to the Sava River vicinity, an interesting technology that can be implemented is aquifer thermal energy storage (ATES). The technology uses two boreholes drilled into the aquifer. During summer, groundwater is extracted via one borehole to provide cooling, while unwanted heat is pumped into the aquifer via the second borehole. In winter flows are reversed, extracting warmer water to provide heating. ATES provides all of the heating and cooling needs and meets 18% of the building’s entire energy requirement. The remaining needs are proposed to be met with local generation systems. A biomass Central Heat and Power is proposed as a suitable option. The CHP provides both the energy supply and the heating to achieve winter comfort. The entire general lighting system is to be implemented with LED technology and other low energy equipments such CFL.
TRANSPORTATION As previously mentioned the BHWC is a major transportation hub. Schemes to encourage public access and bicycle use are to be implemented. Part of the parking garage is proposed to be used as a car pooling scheme to promote car share.
MATERIALS As much as possible, construction materials are to be obtained locally. Both the building and the park are largely covered in stone (limestone, granite, marble) preferably from national quarries. Our project encourages the use of recycled materials such as the structural steel. Preferring the local industry promotes the local area and diminishes the materials’ carbon footprint. Low
embodied materials such as timber are largely proposed in the interiors. Timber has to be FSC certified.
LAND USE AND ECOLOGY The BHWC project is a major urban recovery of an underused site, due to its strategic location. The significant increase of the pedestrian area and promenade connections in this proposal would be a great benefit to the area. The design promotes a landscaping design which encourages the plantation of local plants and trees, strategically located to provide linear shading within the BHWC Park. Biodiversity is promoted by echoing the local vegetation. The land obtained from the excavation is proposed to be relocated in a local project (road work or construction).
WATER Water saving schemes are proposed, such as gray water for toilet use. Rainwater collection retrieved from the BHWC rooftops is saved for watering and toilets. Where required, park design considers Sustainable Urban Drainage System –SUDS- to control potential flood areas.
MANAGEMENT A soft landing scheme is advised to teach users about the energy-saving measures and technologies implemented in the building. A general energy manager can be responsible for the specific management of individual rooms, and provide qualified technical back up.