CAREER Q&A

Deflecting the heat of climate change

Rebecca Powles explains how increasing pressure to deliver energy-efficient buildings is creating opportunities for environmentally conscious scientists.

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A birds-eye view of a construction site next to a road junction.

Construction in Australia has to meet energy-efficiency targets.Credit: Brook Mitchell/Getty

Rebecca Powles is a data analyst with Team Catalyst, a company in Sydney, Australia, that investigates how buildings use energy. She tells Nature about using her background in applied physics to create more energy-efficient buildings.

How does your work help reduce greenhouse-gas emissions?

Buildings are responsible for around one-third of global energy-related carbon dioxide emissions, largely owing to the fuel used to provide power for heating, cooling, lighting, appliances and equipment. This is why reducing the energy demand of buildings is very effective in cutting greenhouse-gas emissions.

Our company makes suggestions to property owners about how to make their buildings more sustainable. For example, I research how windows can be made more energy-efficient. I also work with policymakers to help them devise regulations that will drive improvements in the construction and operation of buildings.

How did you get into this field?

For my PhD at the University of Sydney, I studied thin-film coatings on glass for energy-efficient windows. In 2003, after my postdoc at the Lawrence Berkeley National Laboratory in California, where I measured and modelled the properties of windows, I couldn’t find a physics position in Sydney that focused on building construction, so I joined the University of Sydney’s School of Physics and worked on a range of materials-science projects.

However, in 2016, after a career break, I was determined to try to return to my original field. Some of my former colleagues were running their own consultancy business, so I approached them for advice. They had some work available and were very supportive in getting me up to speed on the necessary skills, such as how to conduct energy simulations of whole buildings.

What do you do now?

I simulate how buildings use energy. Using computational models, we can design new buildings and retrofit old ones with better energy ratings. I also improve the existing software that’s used to do this. Right now, my research is focused on improving models that predict the performance of laminated and printed glass on the exterior of buildings, for example by incorporating how solar radiation is absorbed and scattered as it passes through the layers of laminate.

Tell me more about sustainable-building policymaking.

Like many countries, Australia has building regulations that include energy-efficiency targets. Every few years, the regulations are updated to reflect changing building products, increased standards and other factors such as energy and technology prices. We support that process by testing models to ensure that buildings can realistically be made energy efficient within the new guidelines.

What are the greatest challenges of your work?

The greatest challenge is my own window-modelling work. It is very difficult to get repeatable measurements of light-scattering materials using standard optical instruments, such as a spectrophotometer, which measures the intensity of light. But manufacturers and architects can rarely afford the specialized equipment to do a more rigorous analysis.

I also find I am part of a much bigger ecosystem than when I worked in academia. I have to be aware of the needs of businesses, industry associations and government agencies.

For example, say you are designing a method for assessing the energy performance of a window. In an academic setting, you focus on finding the most accurate technique possible. However, manufacturers are not always keen on trying out new assessment methods. It takes time, and sometimes their products end up performing poorly. Finally, if you want to incorporate the method into government building regulations, there are further levels of bureaucracy and politics to work through.

It’s very interesting, but also challenging to stay on top of all the elements.

What kind of scientists can get into this area?

People enter this field from a range of backgrounds, mostly architecture and engineering, because there are few institutions that teach building physics as part of a science degree. I’ve certainly used my physics background directly in my work, especially around glass and modelling how solar radiation moves through the layers of buildings. If your background includes a solid grounding in basic physics or engineering and good skills in numerical and computational analysis, this would get you off to a good start in my field.

However, to leave the academic world as an early-career scientist is also a pretty big decision, because it can be hard to return to academia from the commercial world. I would generally recommend developing some meaningful experience and a strong track record in your current discipline before considering a change — this might provide you with the most career options.

Have the bush fires in Australia had any impact on how you do your job?

They haven’t directly impacted my day-to-day job, but the fires have led to a more immediate focus on the effects of climate change, which makes people think ahead to how their buildings will perform in a hotter and more variable climate. That is certainly relevant to my work. To develop building codes that will come into effect in the future, we model building performance using weather data that have been adjusted to a variety of future climate predictions.

doi: 10.1038/d41586-020-00774-2

This interview has been edited for length and clarity.

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