All You Need to Know About Curtain Wall Systems

Apr 05, 2022

Glass Façade is the most influential building material creating flawless envelope around the building. Glass builds illusional forms of solid and void exterior that now dictates most of the city skyline.

Favored approach of a tall structure is a glass it’s a style quotient, it’s also one of the fastest construction preferences. Aside from loading a contemporary yet open look to a cutting-edge building, glass façades likewise offer good acoustics and heat protection, making them a top choice of architects. Bespoke cladding, challenging geometrical designs, and striking outlooks of glass facades guarantee insurance against unpredictable breezes and seismic conditions too.

As an architect, if you are intrigued with the nuts and bolts of a façade, here is a significant aide about the complexities of glass facades.

Now, what are the types of Glass Facades?

● Curtain wall

● Store front Wall

And then you have framing system!

● Stick Systems

● Unitized System

● Semi-Unitized Systems

Curtain walls

Curtain walls are non-load bearing drapery like structure appended to the floor wherein the façade is to be joined. This construction type does take the dead load weight forced by the entire building structure. Connections exist between the curtain wall and the structure's sections and floors with the goal that the heaviness of the breeze can be moved from the façade. These sorts of curtain walls are both stylishly satisfying and extremely utilitarian, giving protection from wind and water penetration. Protection from seismic powers and a warm boundary are likewise given by such glass facades.

Curtain Wall

Stone front Wall

This is another non-load bearing façade type planned fundamentally for ground floors. It ranges between the ground and the top of the structure above it and offers ideal warm and sound protection while built utilizing glasses. It is a practical choice and can be tweaked by the customer's longings.

Storefront Wall

Framing Systems: Unitized System

As the name proposes, such glass exteriors are typically made in the factory and afterward conveyed to the site of establishment. This basically implies that unitized frameworks come fit to be introduced at the structure. The persistent framework can traverse various floors in tall structures. Vents and windows can likewise be introduced in unitized-outlined facades. Since the whole outlining framework is developed in an industrial facility with controlled climatic conditions, highlights like dampness and air obstruction can without much of a stretch be consolidated into them. Versatile road cranes, tower cranes, or monorails are normally used to convey the finished frameworks to the site.

Why Prefer

● For larger project, it is convenient – increases the speed of installation & reduces total cost. Most preferred for façade surface over than 5000 Sq.M.

● When the floor height is constant & the span between the mullions are repetitive.

● For building structure more than 6 floors, unitized system will offer ease of installation.

● It is also best of large span of glass frame; unitized system offers better protection for glass with its framework.

● For areas in seismic zone, unitized system has better absorption & perform well in differential movements.

Unitized Framing System | JTI Headquarters, SOM

Curtain walls can be altered by the need of the structure and the plan decision of the customer. It can appear as many intriguing examples as possible and styles. One such innovative example is JTI headquarters by Skidmore, Owings & Merrill (SOM). This project won 2017 Excellence in Structural Engineering: Most Innovative Structure Award from Structural Engineers Association of Illinois.

JTI Headquarters, SOM

The Closed Cavity Facade system was developed as a unitized framing system responding to the requirements This closed cavity facade offers a new approach to the double skin system, the façade system also adheres to European Energy Directives & Swiss sustainable rating.

Glass façade design offers panoramic views, brings abundant daylighting, more sky exposure for occupants and refined aesthetics. The system consists of triple glazing, the cavity between the inner and the outer layer is fixed a fabric roller blind. The double skin panels are sealed which is also equipped with pressurized and dehumidified air supply. This system avoids the condensation & building up of heat inside the hollow cavity space. The fabric roller blind also helps achieve low G-value. The low-iron composition reduced the pale green coloration of the glass achieving neutral colour, along with low emissivity coating it façade system ensures low U-value

Typical Module of Glazing unit, JTI Headquarters, SOM
Mullion Detail, JTI Headquarters, SOM
JTI Headquarters Facade, SOM

Framing Systems: Stick System

Vertical help mullions structure the edges for these sorts of glass exteriors. These expulsions are generally altogether built away from the site of establishment. Afterward, the mullions are taken to the area of development, and glass boards are squeezed into them. Ordinarily, the upward expulsions are likewise upheld by horizontal frames, which thusly, make the glass outlined from all sides.

Generally, the mullions utilized in the stick frameworks are made utilizing materials like aluminium, steel, cement, or wood. Contingent upon the expressive decision, any of these materials can be utilized. Structured silicone, toggle-locked, bolted, or pressure-capped stick systems are introduced in mid-ascent or low-ascent structures considering their significant expenses.

Why Prefer

● For larger project with façade surface between 3000 - 5000 Sq.M.

● Ideal for design style with less repetitive forms.

● Best preferred for irregular complex forms, even 3-Dimensional façade surfaces.

● For building structure with extended façade and lower height and with ease of access from the outside.

● Economical option for lower volume façade system.

Stick System | Grace Farms, SANAA

The Grace farms designed by SANNA features a frame less stick structure, that comprises of three key elements:

FLAG POLES - Hundreds of them, made of steel pipe. These columns were individually fixed at the base of the structure providing an overall lateral support system that did not require a framing or cross beam structure to achieve stability.

STEEL BEAMS - A chain of 10” x 10” steel beams bend in both axes were fabricated specifically to address the contour challenges in the site. It also included steel trusses for large spans & larger over hangs.

INFILL FRAMING – Glass was primarily the infill materials between the stick frames, it also consisted of lumber & laminated wooden beams wherever limited view or privacy was concern.

The Grace farms designed by SANNA
Typical Stick frame Structure, Grace Farms / SANNA

Framing Systems: Semi-Unitized Systems

Semi-unitized frameworks also known as mullion transform façade comprise of the best of both stick frameworks and unitized frameworks. Glass facades of this kind are encased in stick-made metal cassettes. The glass is in-filled in the cassettes at the manufacturing plant. The singular cassettes are subsequently conveyed to the site of development and are gathered with different cassettes nearby. The holding of one metal case with another occurs with gaskets, making the gathering and establishment both quick and safe. These kinds of frameworks require the utilization of primary silicone during the establishment interaction.

Why Prefer

● When vertical & horizontal mullions can be erected separately.

● The span can range for over two floors.

● Greater Structural stability, as it’s anchored to the face of the slab with embedded plates or tubular inserts.

● Can be shop assembled or even assembled off-site.

The mullion transform façade design is centered on the concept of connecting the vertical & horizontal million and commonly used construction technique. Most suitable structural design for any residential or commercial design projects.

Closing Thoughts

The project examples illustrate innovation in curtain wall & different framing system, positively this showcases on how to choose façade framing unit for your project. However, if you have more question or want to collaborate with structural designers and manufacturers Download Arkihive .

We are now live on the Play Store & iOS. Connect with professionals from the Architecture & Construction Industry!


Anusha Ashok

I believe only art can change the world! Although, I constantly critique the design approach & in dispute with my belief. But usually found having tea & listening to Coldplay.