advanced building skins 14 | 15 June 2012 - lamp.tugraz.at - Graz ...

Advanced Building Skins
Of the two basic types of functionalities, conditioning and service, only those related to conditioning
imply regulation of energy and material flows through the façade. These functionalities play the
largest role in the design and definition of the materials that make up the enclosure.
Service-related functionalities have little relevance when choosing materials, although they do play a
role in the exterior finishes. They should also be taken into account when designing the assembly of
layers that make up the enclosure, although normally these will not imply considerable variations to a
design aimed at conditioning in- and outflows.
Functionalities of conditioning that can or should be resolved by the inner skin of the façade
Stability of the skin itself and of the façade as a whole
Thermal comfort
Fire resistance
Acoustic insulation
Airtightness
Service functionalities that can or should be resolved by the inner skin of the façade
Though service functionalities cannot be assigned quantifiable values, they do have an impact on the
design of the enclosure. The installation of utilities can influence the superimposition of layers while
also favoring given geometries for the panel.
Providing a finished interior surface
Providing a space for service utilities
Other requirements demanded of the inner skin of the façade
There is no limit nowadays to the non-functional requirements demanded of panels that withstand
wind load; specifically, these arise from consideration of the issues of slenderness and light weight,
which are factors that condition the development of façade solutions.
Panel thickness is reduced to the minimum possible value, as this entails an optimized relationship
between the built and useable surfaces.
The advantages of a lightweight panel – in terms of diminishing the possibility of overloading and
simplifying on-site manipulation and transportation – are counteracted by the inverse relationship
between acoustic buffering and mass.
In order to make use of lightweight panels without undergoing an extreme reduction in acoustical
response, panel weight has been set to the maximum established by the CTE for lightweight façades in
the document “Protección frente al ruido” (“Protection against noise”); in other words, 200 kg/m².
Slenderness
Light weight
4 Taxonomy of Panels for an Inner Self-bearing Skin Based on Criteria of
Functionality
4.1 Relevance of the Criterion of Functionality
To choose an organizational criterion, it is important that one have a clear notion of the element to be
analyzed; in this case, it is the inner skin of the ventilated façade. Likewise, one must know the
context in which the desired results can be met.
Objective: To satisfy the functionalities necessary such that the façade – as a whole –
provides an acceptable level of comfort inside the space it surrounds.
Context: Development of building systems.
The design of a panel for the inner skin of the ventilated façade depends on the functionalities it must
provide a solution to. Its typically null presence in the finished building gives it a purely functional
character, which is not conditioned by formalism or other subjective variables.
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