Architectus Principal, Marko Damic, explores the departure from sleek, reflective glass towers to high-performance facades for a more sustainable future.
From Glass to Green
Over the last two decades, sleek skyscrapers encased in glass have been a common sight on our city skylines. An international trend projecting an element of prestige and power, the façades of these gleaming towers were relatively cost-efficient and straightforward to replicate and so began to proliferate.
Here in Australia, that style has come at a price: Think air conditioning systems working overtime and office workers lowering blinds as their buildings bake in the sunshine.
But our love affair with glass is now giving way to high-performance façades designed for a more sustainable future, points out Architectus Principal, Marko Damic, whose analytical approach to design challenges has led to some of our most innovative ‘skins’ on commercial buildings.
In this article, Marko talks about new directions in façade design since significant changes to National Construction Code regulations in 2019 and 2022. He also shares insights from projects like Array at 1 Eden Park, featuring a carefully calibrated façade that balances environmental efficiency and aesthetic appeal, thanks to collaboration between the practice’s Commercial and Architectus Digital teams.
The Shift Towards Sustainable Façade Design in Australia
Globally, it’s estimated that over 70% of emissions from the building and construction sector are generated in the usage phase of a building’s lifecycle, according to the 2019 Global Status Report for Buildings and Construction.
The energy expended in heating and cooling is a big contributor to that emissions profile – a situation exacerbated by façades that haven’t been designed to respond to the demands of our climate.
Fortunately, Australia is taking steps in the right direction after refinements to our regulations, including those governing the performance of our commercial buildings.
We’re identifying and incorporating more impactful sustainability measures when designing façades.
These important changes do more than shift us toward more sustainable commercial development overall. They can help us achieve carbon neutral operation in the future – and possibly even a carbon positive, environment repairing construction industry.
From Limitations to Innovations
Out of necessity, these new rules introduce some constraints to the process of designing commercial towers. But limitations can lead to innovations, as designers shake off any preconceived notions and explore new approaches.
The changes have also highlighted the increasingly important relationship between computational design and architectural design as we strive for more tech-advanced, sustainable solutions for façades and beyond. The analysis and modeling of specialists like those in our dedicated digital team are becoming even more vital and integrated.
So how do these new directions in façade design play out in our built environment?
With building performance under scrutiny, we’re seeing design aesthetics change to support more efficient operation, with buildings projecting more overtly environmental features.
Overall, there will be a greater degree of solidity in our façades, given the 40%- 60% suggested minimum coverage to achieve good solar performance. Self shading buildings and photo voltaic panels will also become increasingly common.
Three of our recent projects are great examples of these new and emerging design moves, though we took a vastly different approach to each.
Array at 1 Eden Park: A first in façades
Array at 1 Eden Park in North Ryde, Sydney was the first building to come online following the 2019 Code changes.
The client’s brief for the 10,000 sqm, 7-level development was clear: deliver a visually and technically unique building to differentiate it within the market while also achieving high environmental standards.
Signaling the future of new commercial buildings, Array made the shift from the archetypal ‘glass box’ so common in its precinct to a more expressed façade projecting an environmentally-friendly approach.
During the design process, our focus was on finding the right formula for an appealing building that didn’t rely heavily on glass but was still connected to the outside. At the same time, we wanted the building’s physical appearance to be derived directly from the context and orientation of the site.
Collaborating with Architectus Digital, we used thermal mapping to develop a self-shading building form that carefully integrates solid elements to optimise façade performance and control solar heat gain.
Resulting in an eye-catching, geometric patterned exterior, the parametric design is effectively a high-tech design solution using a common, low-tech façade system.
Made up of 60% white terracotta cladding and 40% glazed panels, the façade is arranged to block harsher sunlight from the north and west and open the building to its east.
The clear, full-height glazing on this eastern elevation connects the deep western portions of the building to the central precinct and to views of Lane Cove National Park while also bringing the morning sun deep into the office spaces.
In addition to sun protection, the façade’s distinctive ‘blades’ and carefully positioned, deep window ‘reveals’ allow for elevated views and natural light from the site’s northern aspect.
Self-shading extends to the whole building form, which steps down towards the east to complement the scale of the central precinct. This design move also protects Array’s roof terraces from the western sun for greater use and enjoyment of the outdoor spaces.
Ultimately, our parametric-modeled solution for Array achieves an optimum balance between performance and amenity, delivering an innovative and environmentally responsive façade.
1 Spring Street: A staggered system
For the proposed redevelopment of 1 Spring Street in Melbourne, we created a self-shading building form supplemented by a system of staggered façade elements.
This approach maximises shading and allows for the potential integration of photo voltaic panels in the future. At the same time, it optimises natural light penetrating deep into the workplace.
A competition won in a design collaboration with international practice Ingenhoven Architects, the concept for the 28-story mixed-use office tower, like Array, reflects a genuine interplay between computational design and architectural design to achieve a sustainable solution.
Together, the building envelope and high-performance façade self-shade the floorplates while still allowing for optimal daylight penetration.
To complement the façade’s performance, we spread out the building’s mechanical systems, with each floor effectively isolated from the others.
The aim: to supply natural air directly from the façade, optimise fresh air changes and improve airflow.
In addition, we treated the building’s lobby spaces as naturally ventilated extensions of the public realm.
Like a pocket park extending into the building’s footprint, this approach effectively erases traditional boundaries between the interior and exterior of the tower’s entry. Collaborating with Harry Seidler & Associates, we carefully designed the spaces to respect the existing heritage-listed 1 Spring Tower (formerly known as Shell House).
With its innovative façade working in concert with all these other elements, 1 Spring Street becomes a more flexible, healthy space where wellness and comfort are priorities.
153 Walker Street: A new view
For this premium tower in North Sydney now awaiting approval, our façade design is a direct response to environmental conditions, balancing solidity and openness to maximise views.
During extensive testing, our design team investigated different façade options and shading layouts. We discovered that vertical external shading elements – coupled with vertical spandrels – achieved the best balance between shading efficiency and daylight penetration while retaining angled views of Sydney Harbour.
Our diagrams show a reduction of over 40% of radiation on the building’s eastern elevation once we introduce this carefully modeled shading system. This efficient strategy also allows for a high shading coefficient (over 0.25), resulting in a simple and transparent DGU system (better + 55% VLT).
By placing the core to the north – with a simple, single-glazed ventilated cavity skin to the elevators effectively creating a double skin façade – the majority of the heat loading has been removed from the building.
This approach simplifies mechanical systems, optimises efficiency, and maximises access to daylight.
It also creates a distinctive, active façade when the building is seen from the north – yet another example of how commercial design is ‘facing’ the future.
This article was inspired by the original blog post here.
Images and sketches are courtesy of Architectus.
