The Evolution of Façade Design
The first building introduced with a curtain wall was the Crystal Palace in the Great Exhibition held in London in 1851.
The Crystal Palace in the Great Exhibition, London, 1851, pioneered façade design. For the exhibition hall for most exhibits, a greenhouse-like frame glass structure was adopted, which not only rendered the Crystal Palace the most glorious of all exhibits, but also pioneered façade design engineering.
After nearly a century of development, façade fabrication, in terms of type, has developed from a simple exposed-frame glass one to a semi-exposed-frame or hidden-frame, full-glass one, as well as using various metal, stone, or artificial panels; in terms of structure, the façade fabrication has developed from a simple frame one to a unitized, point-supported, double-skinned, and membrane-structured one; in addition, more energy-efficient, ecological façade panels, photoelectric façade, and intelligent façade are gathering momentum.
Obviously, façade design technology is advancing rapidly. It helps architects free their minds and enables façade design to develop from being simple and monotonous to diversified, complex, and modern.
Architectural envelopes market is mainly driven by the development of the global economy and building industry. Global economic growth promotes investment in fixed assets, and the construction demands of all kinds of public facilities, commercial buildings, and high-end residential buildings provide a foundation for the growth of global architectural envelopes markets.
From the distribution of global architectural envelopes markets, it can be seen that the U.S. and Europe are still the dominant players, combined market share accounting for about 50% in 2009.
In the meanwhile, the emerging countries represented by China and India are enjoying rapid growth of their architectural envelopes industry.
According to related statistics, China is the country with the most super high-rise buildings being constructed and planned in the world. The number of buildings in the country above 200 meters accounts for 48.5% of the total number of the buildings in the world. A large number of projects to be started in the future will demand much from the architectural envelopes industry.
It can be predicted that in the future, the U.S. and Europe will still take the lead in the design and application of architectural envelope products, and the developing countries of Asia (especially China), the Middle East, and other regions will be the main battlefield and driver of new products and application demands of the architectural envelopes globally.
Industry Challenges
The traditional building industry suffers serious productivity waste because of poor utilization of building materials, engineering rework, idling of labor, etc. According to related statistics, the value of the resources wasted in construction for a project accounts for as much as 25% of the total investment, largely wasted in façade design, fabrication, and installation.
For sustainable and healthy development of the architectural envelopes industry, it is required to analyze the reasons for the waste from the perspective of the full lifecycle of a façade fabrication, examine the challenges arising in the development of the architectural envelope industry, and grasp the opportunities of industry development.
Challenge of project management mode
Façade design (especially for complex curtain walls) is a highly professional engineering task requiring a distinguished appearance, technical functionality, and significant investment in installation planning. So, like structural design, plumbing design, and electrical design, a façade design requires special expertise.
Typically architects designing façades try to avoid a single manufacturer’s product so that the contractor can bid alternatives. This means that the architectural drawings are not coordinated with shop drawings from a manufacturer until construction has started and by that time much expert knowledge has been missed with several consequences:
- the final design deliverables fail to embody the progress of façade technology and new products; and
- the design scheme cannot meet the building energy performance requirements in an economical way.
For a close coordination between façade design and main building design, an independent third party as façade design consultants are important.
At the building schematic phase, the architects ask the façade design consultants for advice on their schematic design, so as to make possible the best building appearance; at the design development phase, the façade design consultants determines the system to-be-adopted, reserved room, etc. for the architectural envelope to provide more refined façade design drawings for façade contractors bidding.
The façade consultants should be able to produce a 3D model that incorporates the architect’s construction drawings and fabrication drawings.
Data breaking from design to manufacturing
Compared with the traditional building industry, façade design engineering is mostly based on custom manufacturing in plants. It is an industry formed from the close combination of building and industrial manufacturing. It is hoped that the accurate 3D model and 2D CAD drawings of a complex façade models can be completely sent to the numerical control cutting machines in plants.
However, due to lack of relevant cross-industry standard criteria, the data chain from façade design to manufacturing breaks, resulting in poor collaboration in problem solving, which seriously affects the industrialization of the architectural envelope industry.
Furthermore, because of the limited accuracy of many BIM software programs in parametric modeling of the components, 3D models cannot be directly applied to industrial fabrication. When an architect changes 3D models, the façade designer has to redevelop the detailed façade design and generate new fabrication drawings independently, thus causing a huge waste due to delay and rework.
Production and installation requirements of a complex curtain wall
Compared with traditional manufacturing, a façade panel has a higher degree of customization, which is reflected by not only different designs for different projects, but also different façade panels even in a project, so fast and flexible production is required as needed.
With the emergence of new materials and new technologies, and people’s constant pursuit of different building appearances, façade fabrication becomes bigger and bigger in size and increasingly complex in shape, accompanied by increasing of difficulties in field installation. In this case, if the delivery sequence and installation process are not well managed, the installation positions of façade panels may be confused, thus causing project delay and the waste of resources.
It is a pity that seamless connection of data for detailed façade design drawing, detailed joint fabrication technology, and field installation positioning (as well as realization of drawing-less and model-driven fabrication design which is a concept advocated in the machinery industry) is now beyond the capability for most BIM tools.
What we need is an accurate data integration environment incorporating building design, detailed joint design, and field installation together covering a series of management activities, including façade fabrication production, positioning, detection, cost estimation, and risk control.
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