Speaking about building’s facade design means talking about one of the most important design challenges in architecture. It also means talking about the design of buildings’ skin with a focus on durability, safety and protection, energy performance, weather conditions, construction, maintenance and cost control. All of these factors combining to create a symbiotic relationship with external aesthetics.
This is why, in all major architectural projects a facade designer plays an essential role within a building facade project team and represents an important professional reference for the creative output of architects.
Brief history of facades
Throughout architectural history, buildings’ facade have had a strong connection and importance as they were intimately linked to the aesthetic and socio-cultural values of the age and of the people who built and commissioned them. A premise that linked technologies and symbolic contents to the facades themselves, starting from the pre-historic shelters to the first houses and public buildings aimed at satisfying primary needs and styles.
From the periods of the ancient civilizations, which have strongly innovated the technologies of the buildings and the symbolic values of the building facade, right up to the classic golden age, the focus shifted to proportions and specific theories on harmony in reference to the building skin.
Taking an evolutionary path that continued into the Middle Ages, and up until the Renaissance, facades originated primarily from the topological and spatial solutions of the buildings themselves. Modifying again, at the dawn of the modern era, with facades showing their own autonomy with respect to the type of building, favouring abstract concepts and stylistic exercises.
Then with the new millennium a new technological evolution of building facade was spawned by the birth of a discipline specialized in the specific design of the facade itself. A discipline that distinguishes a new approach from the historical design perspective of facades.
This was driven by the need to guarantee comfort conditions inside the building; the need to comply with environmental and energy performance requirements; and to evaluate, measure and push the technological progress of the facade engineering to a level not seen before.
Responsive façade design engineering
Design instinctively responds to specific technological challenges and requirements of law in regard to the performance of materials, structural behaviour, safety, fire prevention, weather-tightness, acoustic and energy performance, as each element is regulated by both European (EN) and International (ISO) standards.
In energy performance for instance, there are different parameters which the building envelope needs to be compliant with, and which strongly affect the facade design. Like the HT (the average thermal transmittance of the building envelope, including opaque and transparent areas) and Asol, which is related to the solar control properties of glazed facades, including shading systems, driving the design of the building envelope, especially when the architectural requirement is for a full structural glazing solution.
Today, there is a growing interest for the adaptive facades, also called intelligent facades, which through their capability to adapt their behaviour according to the different indoor-outdoor conditions improves the building’s energy efficiency. Sometimes triggering the most innovative and sophisticated of solutions, conceived to exceed all expectations of clients.
Facade design means dealing with building physics
Depending on the project complexity and performance targets, a wide range of analysis is carried out at the pre-design stage. This includes: sun path and shading analysis, natural and mixed mode ventilation and environmental assessments, daylight & glare analysis, energy modelling, thermal comfort, noise modelling, building noise assessment, and computational fluid dynamics (CFD).
To fully meet these stringent purposes, advance software and expertise maximizes the use of the technology driving the process of analysis every step of the way. Solar and shading, thermal loads and Energy Modelling are just few of the complexity of the analysis processes followed even before the designing of the façade begins.
Advanced parametric tools are used to optimize the design of the shading systems with regard to solar gain and glare control and maximization of daylighting. These advanced tools are found really useful, especially at the concept design stage, as it is possible to analyze different façade configurations providing the architect with useful input and make informed design choices.
Working in sync pays big dividends
Total collaboration between the architect and the façade designer is crucial right from the architectural concept stage. In fact, outputs from detailed analysis are used as input for the architect to optimize the design of the façade itself.
Numerous iconic façade projects across the globe are the result of detailed analysis processes supported by advanced tools. Take for instance, designing a single skin façade with fixed external shading. This kind of concept, calls for a comprehensive analysis, in order to assess the shading factor, i.e. the percentage of solar radiation blocked by the external shading system before reaching the structural glazing.
In order to comply with ISO regulations on energy performance, the amount of solar radiation entering the building structure has to be within a pre-set total solar radiation incident on the façade. Which is why a parametric analysis is deployed to explore different shading configurations.
If the façade incorporates vertical fins, then the impact of radiation is assessed by varying the geometric data (depth, orientation) .If the design concepts also calls for the integration of horizontal louvers, then this too needs to be taken into account and assessed accordingly.
The results from such analysis are then used by the architect as input for the design of the shading. The architect decides whether the vertical fins need to be designed with a trapezoidal geometry or not, and have variable depth at the top and bottom of the fins. Incorporating these design factors by always keeping a mean depth in compliance with the façade analysis.
It is only after exhaustive analysis, can a building be characterized by a diagrid shaped fully glazed double skin façade, naturally ventilated with external air through linear openings integrated on the external skin at each floor level. The weather and thermal barrier can be provided by the inner skin, while solar control can be provided by venetian blinds placed in the cavity between the two skins.
Analysis precedes design, always
In almost every project with large outlays, the design team and the client always insist on evaluating the impact on the climatic behaviour of the double façade for different configurations involving the variability of some parameters: positioning and type of blinds within the cavity, solar properties of the glazing on both the inner and the outer skin, the size and the distribution of the ventilation openings on the outer skin.
Today there is a growing interest for the adaptive facade (also called intelligent or responsive facades) which through their capability to adapt their behaviour according to the different indoor-outdoor conditions can improve the building’s energy efficiency and comfort levels.
A large share of the energy use is associated with protection from the external climate and operation of systems necessary to give the occupants a comfortable indoor environment. Natural light is also seen as a key driver to people’s well-being both in the workplace and at home. And the biggest advantage, huge annualised savings is most welcome by everyone.
About Aparna-Craft
Developing facade solutions capable of responding to the needs of the occupants of both new and refurbished buildings is a key area that Aparna-Craft focuses on. Aparna-Craft is among the very few end-to-end façade solution providers in India, who can bring years of experience in the field of façade design, engineering and installation.
Aparna-Craft draws upon the expertise of working on large and small projects across APAC with renowned architects and perfecting its expertise in designing, manufacturing, and installing building facades.
Aparna-Craft has earned impeccable credentials and established a reputation for executing customized façade solutions seamlessly and delivering projects on time and within specified budgets.
