Greener perspectives: Matthias Irger

Architects and designers are at the forefront of shaping not only how places look but also how they are built. For our third edition of Greener Perspectives we spoke with Dr. Matthias Irger, Head of Sustainability at Cox. Here’s what he had to say about his commitment to regenerative solutions and the importance of driving low-carbon solutions:

 

 

Can you share a brief overview of your journey and career in architecture and what drew you to focus on sustainability?

 

 

I studied architecture and urban design in Germany, with an internship mid-way through in Sydney. After completing my degree, I began my career at Helmut Jahn’s firm in Chicago, focusing on tech-driven high-rises. Then in 2004, I moved back to Sydney and joined Cox, marking the beginning of my journey with the firm.

 

After some years at Cox, I left to work on 8 Chifley Square—a groundbreaking project at the time. It was Sydney’s first Six Star Green Star commercial office tower designed by RSHP, and I worked on it while at Lippmann Partnership. This deepened my passion for sustainable design and led me to pursue a PhD in Sustainable Urbanism, focusing on climate adaptation and urban heat mitigation. Eventually, I returned to Cox, where I’m now Head of Sustainability. Coming to Australia 20 years ago, I noticed that sustainability standards were far lower here than I’d experienced in Europe. That realisation was a pivotal moment for me—it fuelled my determination to understand how we could lift the bar and improve outcomes, not just in architecture but across our cities.

 

 

How do you integrate sustainability into your day-to-day work and project designs?

 

 

At Cox, sustainability is embedded in everything we do—it’s part of our DNA. Philip Cox founded the company over 60 years ago with an environmentally conscious approach, and we continue to honor that legacy. It’s reflected in our studio values, like “create to last” and “do more with less,” which resonates deeply with our team and clients alike. Using fewer materials, reducing carbon, and creating durable, lasting buildings are key principles we follow.

 

As Head of Sustainability, I’m involved in many projects across our studios, guiding our strategic direction on carbon reduction, material circularity, and building disassembly for end-of-life considerations. I also work closely with our teams through education and advice on improving design outcomes.

Image above: SBRC, Wollongong, NSW.

Were there any pivotal moments or projects that significantly shaped your approach to sustainable architecture?

 

 

A pivotal moment for me was realising the massive responsibility architects and planners hold in addressing climate change. The built environment contributes to about 30% of global carbon emissions—10 – 11% from the materials we use and the rest from operational carbon. This made it clear that simply being “sustainable” isn’t enough. We need to shift to regenerative design, creating buildings that are net positive and give back more than they take, especially as we’re consuming resources far beyond what the Earth can sustain.

 

One project that stands out is the Sustainable Buildings Research Centre (SBRC) at the University of Wollongong, Australia’s first certified Living Building. This project proved that net-positive buildings are achievable if approached correctly and supported by an ambitious client.

 

The SBRC excels in passive design—artificial lighting is rarely needed, and air conditioning is unnecessary, creating a space where people feel healthier and more productive. The use of reclaimed materials like old timber and recycled brick adds warmth, comfort, and creates a sense of place.

 

This project inspired the establishment of the Living Future Institute in Australia and demonstrated how architecture can create spaces that positively impact both the planet and its occupants. It’s proof that sustainable, regenerative architecture isn’t just aspirational—it’s achievable.

Image above: The SBRC is Australia’s first and still only fully certified Living Building. The SBRC is net positive in energy and water, and was built with local, reclaimed materials such as brick and structural timber.

How does circularity influence your material selection and what challenges have you encountered in sourcing sustainable materials?

 

 

Circularity is a core principle in our design approach, working alongside carbon reduction efforts. We focus on designing for disassembly by using mechanical fixings instead of glue, ensuring components can be reused or recycled. We prioritise materials with high recycled content and adaptive reuse, repurposing buildings or components rather than demolishing them, which helps reduce carbon emissions and waste while saving costs.

 

However, sourcing sustainable materials in Australia can be challenging due to a lack of transparency around carbon metrics and supply chain data. We often face the dilemma of choosing between local products without the necessary information and imported ones with certifications. To address this, we helped develop Product Aware, a database that gathers sustainability metrics for both local and international products, streamlining material selection and educating the industry on the data we need. We hope this initiative encourages more local products to provide transparency and facilitates the transition to more sustainable alternatives, particularly in high-carbon materials like aluminium.

 

 

What role do you believe architects play in driving sustainable practices in the construction industry?

 

 

Architects play a crucial role in the transition to a low-carbon economy. We’re responsible for a large portion of carbon emissions through the materials we choose, how we design buildings, and how we plan cities. As designers, we have a moral responsibility to act because we have the power to make a difference. Sustainable design is often simple, requiring skillful design rather than complex solutions.

 

With the right skills, we can create buildings that are both sustainable and efficient, offering benefits like lower energy costs, better health outcomes, and higher resale values at the end of their first life. On a city scale, we can make urban spaces more resilient to heat and flooding by integrating nature and improving liveability.

Image above: “Do more with Less”: COX’s Sydney Studio refurbishment achieved a 89% upfront carbon reduction compared to a typical office fitout through dematerialisation and sustainable material choices.

What are some key lessons you’ve learned about sustainable design during your career?

 

 

The most important lesson I’ve learned is to think about sustainability from the very start of a project—it’s a mindset. From the initial concept, we need to consider how to reduce the environmental footprint and aim for net positive outcomes, not just sustainable ones. Understanding the site is crucial, especially considering climate change risks, and how we can mitigate those challenges.

 

Another key lesson is that sustainability doesn’t have to cost more. With passive design, like optimising windows, roof overhangs, and thermal mass, we can reduce costs by saving energy in the long run. Investing in better insulation, air tightness, and glazing upfront leads to long-term savings and a more valuable building.

 

 

How do you foresee sustainability shaping the future of architecture and urban design over the next five years?

 

 

Sustainability will gain more prominence, with a major focus on carbon and climate risk. The shift from traditional design to actually quantifying carbon will be a game changer. Once we have the numbers, we can improve, compare, and benchmark our designs, making real progress. AI-supported optimisation tools will also transform the design process, making it more efficient and making designers’ lives easier.

 

 

What advice would you give to architects and designers who want to start prioritising sustainability throughout their projects where there may be resistance from clients etc?

 

 

My advice would be to think about sustainability in everything you do, no matter how small. Every design choice, whether it’s using fewer materials or selecting sustainable alternatives, has an impact. Continually look at successful projects for inspiration and learn from past mistakes. And finally, don’t forget the basics—understanding the site, optimising solar design, and using technology can make a big difference. It’s all about making small, thoughtful decisions that add up over time.

Image above: Matthias presenting at the Annual Sustainability Awards 2024.