How BIM unleashed the power of Facade Design - Part 2
BIM (Building Information Modelling) is all about providing an efficient and productive way to deliver Architecture, Engineering and Construction projects in general. It’s a new working environment, with less room for errors and unlimited possibilities for improvement. At Part 2, we are about to understand how BIM, through this structured collaborative approach, can help facade experts increase their competence and compliance, and of course deliver better facade projects.
Facade items visualization was never so simple
The most fundamental change brought by 3D BIM technology, compared to 2D CAD approach so far, is that it enables facade designers to visualize the details of the facade elements very easily and identify the challenges they have to address. Throughout the whole design process, from conceptual sketches to visual mock-ups, all facade elements are converted to functional variables, and then by dynamically changing the function, the facade items change accordingly.
The concept of a digital big-room collaborative space
During a complex facade project development, there are so many stakeholders that have to communicate efficiently and take smart decisions at any given milestone. BIM brings all these professionals together in a virtual big-room, regardless of their whereabouts, offering open communication, shared working platforms, common goals and understanding, and a fluid approach. In a world that design-assist is required for the majority of the facade projects, which means that contractors and subcontractors work with designers to develop full digital models, BIM implementation (but only at a certain level) is used to achieve better and more predictable outcomes.
Sky is the limit for complex designs
Another collateral benefit of the enhanced visualization, but equally significant, is the unlimited design possibilities that parametric design (another way to refer to BIM) offers. Until now, facade designers had to stick to conventional systems, having less freedom to design something exceptional. BIM however, is a tool from the future, providing them with inspiration to deviate from traditional facade designs.
Never miss a facade hot-spot again due to lack of co-ordination
One of the most important things in facade design, is buildability, construction sequence, and class detection. Thanks to the enhanced collaboration that BIM provides, it is much easier to identify any potential clashes and make the necessary corrections on paper instead of during the fabrication or construction phase, which usually results in extra costs and schedule implications.
Building simulations are free of charge and time
Another key benefit is the ability to make multiple simulations, calculations and statistical analyses in less time. All the integrated information inside the BIM model, is actually a set of attributes of all the facade components. Factors like materials, u-value, g-factor, cost, purchase data, weight, installation id, structural values, etc. are all dynamic and are changed accordingly, as the design evolves. The facade designer can easily test the thermal and acoustic performance, estimate solar irradiation and lighting, evaluate natural ventilation, confirm structural integrity as well as measure building performance for BREEAM/LEED assessments. This trial and error procedure can be repeated multiple times, until the necessary combination of results is achieved, according to the project requirements.
The Erasmus Pavilion Case Study
The new Erasmus University Rotterdam Student Center, designed by Powerhouse Company in collaboration with De Zwarte Hond, is located at the heart of a new master plan for the University area. Having sustainability, usability, transparency, and intimacy as main objectives, it is set to become a vibrant central meeting point where research meets business and science meets culture. “We approached the design with the idea of creating a building that can actively change its façade — not only to adapt to the weather and the cycle of seasons, but also to allow an adjustable level of intimacy inside, depending on the events.” said Stefan Prins, associate at Powerhouse Company, and added: “By opening or closing the mechanical louvers, users can let in as much or as little light as they want. This leads to reduced energy consumption.”
Powerhouse Company designed Erasmus Pavilion based on the concept of creating a building that can actively change its facade not only to adapt to the weather and seasons, but also to allow an adjustable level of intimacy inside depending on the events. Triple-pane glass and the louvers are just two elements of the ambitious energy-efficient design of the building, which has received the Netherlands’ highest Energy Performance Certificate grade, 0.2, or A++. The building management system can optimize the blade angle for the best mix of glare and heat-gain control, though the settings can be manually overridden. Only the auditorium is fully heated and cooled by mechanical means, which incorporate a geothermal heat pump. Cafe operators can throw open the terrace doors on mild days, and that aids a natural ventilation strategy combining operable windows in the curtain wall with roof hatches that draw out warm exhaust air.
Various technical measures related to BIM were implemented to lower the energy impact of the building. A compact building volume, the positioning of the mass in the center core, a careful orientation of the program towards the sun— combined with the dynamic façade, the solar panels on the roof, the natural ventilation, and flexible zoning, transform this transparent building into a low consumption landmark. With regard to the collaboration method on this project, both Powerhouse Company and De Zwarte Hond used BIM software so there was no need for IFC documentation exchange. The role of both offices was 50/50 throughout the design and construction of the project. “We usually set up a specific team with expertise from both offices to fit the needs of the phase of the project,” Stefan said. “In practice, we worked on one location through a Teamwork project that architects, designers and project managers had access to. In addition, the Teamwork project was also accessible from ‘outside the office. This way the project was always available for both offices.”
Image by © Christian van der Kooy, Erasmus University Rotterdam Student Center, Via Graphisoft