Buildings that capture carbon and support biodiversity

Climate change and biodiversity loss are two of the most pressing issues facing our urban environments today. Te Herenga Waka—Victoria University of Wellington PhD candidate Kamiya Varshney is working to help address these challenges through her research into how buildings can both capture and store carbon and act as a habitat for urban biodiversity.

Kamiya Varshney

Kamiya’s research explores the benefits of using vegetation on and around urban buildings to both remove carbon dioxide from the atmosphere and provide a welcoming habitat for urban flora and fauna. She is aiming to develop industry guidance to help building professionals incorporate these benefits into building design.

“The urban built environment significantly contributes to both climate change and biodiversity loss issues,” Kamiya says. “Architects and designers must consider how their work impacts the environment and how we can help mitigate these issues.”

Green spaces have significant potential to capture and store carbon from the atmosphere. By integrating them on and around urban buildings, architects and designers can make the best use of space possible in an urban area. Integrating them onto all buildings also provides a continuous habitat for urban biodiversity, giving them more chances to thrive and reducing biodiversity loss. Another way to do this is to use native plants in the green spaces, ideally selecting plants that capture as much carbon as possible.

These green spaces can also help make cities more welcoming and liveable for people, which will be vital with the proposed Resource Management Act reforms that enable high-density housing (like townhouses) to be built across many suburban areas, perhaps reducing more traditional green space such as parks.

“Carbon-capturing and biodiversity-positive buildings can contribute to improving ecological health and human health and well-being. These buildings will increase biodiversity and provide social, cultural, psychological, physical and economic benefits by improving workplace productivity, indoor air quality, innate human-nature relationship, aesthetics, social cohesion, and security,” Kamiya says.

“We need to look at architecture and urban design through an ecological lens and embrace ecosystem-based approaches to enhance urban resilience, biodiversity regeneration, and climate change mitigation, and adaptation.”

So far, as part of creating her industry guidelines, Kamiya has surveyed and interviewed architects, researchers, ecologists, other design professionals, and policy experts to understand their views about vegetation-based carbon capture and habitat.

Her initial findings show that building industry professionals tend to focus on carbon emissions reduction or investing in carbon offsetting. Carbon emissions reduction is still vital for achieving sustainability or regenerative targets, even if carbon capture strategies are adopted. They also tend to focus on using materials that naturally store carbon, such as timber. While using building materials that store carbon is important and should be encouraged, it is not the same as carbon capture, which is using the built environment to actively pull carbon out of the atmosphere, Kamiya says.

“Instead of paying for carbon or biodiversity offsets, the building industry could employ strategies for active carbon capture and the enhancement of biodiversity through integrating vegetation and green spaces more effectively into or onto or around buildings,” Kamiya says.

Kamiya will test her findings and guidance across Wellington in the city centre, hill, forest, and coastal environments to understand the different natural processes and demands within these areas. Her research takes into account Wellington City Council’s Our Natural Capital—Wellington’s Biodiversity Strategy & Action Plan, Te Atakura—First to Zero, Planning for Growth and the developing  Green Network Plan to align her research with practical local aims and desired outcomes.

Kamiya Varshney is a PhD candidate in the Wellington Faculty of Architecture and Design Innovation. Her supervisors are Dr Maibritt Pedersen Zari and Dr Nilesh Bakshi.

Contact Kamiya to hear more about her research on