Holo: Passively Cooled Artificial Habitat

Holo began as a broader investigation into artificial habitats for urban wildlife. Through extensive interviews with ecologists and ornithologists, I was directed to CSIRO research highlighting the deadly impact of heatwaves on native bird populations. This insight led me to narrow the focus: could a nest box protect birds from temperature extremes? I began testing materials and concepts for passive thermal regulation. Drawing from biomimicry - particularly termite mounds - and ancient cooling systems like badgirs and trombe walls, I prioritised evaporative cooling and thermal mass. Terracotta emerged as the ideal material due to its porosity, durability, and thermal properties.

The breakthrough came when I noticed water dripping from an air conditioning unit onto the pavement. That runoff could be repurposed to drive the evaporative system. Better still, in winter when ACs aren’t in use, the empty reservoir would act as an insulating air pocket, creating a passive seasonal switch. From there, I developed scale prototypes and tested them under simulated heatwave conditions. Initial testing at 40 deg C indicates cooling of up to 12 degrees is possible - increasing survivability for hollow nesting species. I integrated a planter to promote invertebrate life and boost thermal mass, and added a catchment that local fauna could drink from. Finally, I built a full-scale version using custom slip-cast moulds - over 40kg of plaster and months of iteration.

Holo is a climate-adaptive wildlife habitat designed to support native birds in urban environments during periods of extreme heat. It meets the criteria for good design by combining functionality and sustainability in a simple, considered form. Made from terracotta, Holo uses passive evaporative cooling to lower internal temperatures by up to 12°C - an important feature as traditional nest boxes often overheat in summer. The design is practical, durable, and easy to install, while also requiring minimal maintenance over time.

The form was refined through testing to balance evaporation, shading, and thermal mass. Internally, the nesting cavity is glazed to prevent water ingress and sized for specific genera. This iteration is tailored to pardalotes, a small bird endemic to Australia known for their unfussy nesting habits.  For users - both wildlife and humans - the experience is straightforward and low-impact. Holo is visually, designed to complement the built environment rather than dominate it. It can be wall-mounted in locations where ground space is limited, making it well-suited to dense urban areas. The result is a habitat that’s not just fit for purpose, but designed with long-term usability and environmental change in mind. Holo contributes to a more resilient and biodiverse city, and offers a practical example of how design can quietly support ecological outcomes - both in Victoria and beyond.

Holo takes an unconventional approach to nest box design by focusing on climate resilience and passive performance. Where traditional wooden nest boxes absorb heat, Holo uses evaporative cooling to actively lower temperatures inside the cavity, helping native birds survive increasingly common heatwaves. This was achieved by combining natural materials with passive architectural strategies. Terracotta was selected for its ability to absorb and slowly release water, allowing the habitat to “sweat” and cool without power or technology. Air conditioning runoff, normally a wasted resource, was repurposed to activate the system.

The design even transitions with the seasons: in winter, the reservoir becomes an air pocket that provides insulation instead of cooling. The habitat also includes a small planter and water reservoir, supporting invertebrate life and contributing to biodiversity. The wall-mounted format addresses the lack of green space in urban areas by activating vertical surfaces, which are currently underutilised.  The innovation here lies in how different ideas - passive cooling, greywater use, urban greening - were brought together into a single system. It’s an original response to a real problem, developed through research, prototyping, and field-informed testing. Holo shows that practical, small-scale solutions can still be inventive, and that everyday urban systems can be reimagined to support life in new ways.

Holo is designed to deliver a clear environmental benefit by making cities more livable for native birds during extreme heat events. By passively reducing temperatures inside the nesting cavity, it directly improves the survival rates of small birds - especially during the hottest parts of summer, when conventional nest boxes may fail. In terms of sustainability, Holo uses a single natural material (terracotta), which is low-impact to produce and easy to recycle or repurpose. It uses no electronics or energy and makes use of air conditioning runoff, a resource that is both abundant and typically overlooked in cities.

This type of design is simple but effective. It reduces reliance on powered infrastructure, promotes biodiversity in built environments, and turns underused urban surfaces into potential habitat. Holo was also designed with manufacturing and scalability in mind, making it possible to reproduce locally or integrate into building projects at scale. By using design to quietly improve environmental performance in cities, Holo reflects the broader value of professional design thinking - where solutions are functional, sustainable, and user-conscious. Developed and tested in Victoria, it contributes to the state’s reputation for smart, applied design and could easily serve as a model for similar urban contexts across Australia and internationally.

Holo was developed with sustainability and circular design principles from the outset. Terracotta was selected for its long lifespan, recyclability, and capacity for local production using existing ceramic infrastructure. It’s durable, non-toxic, and requires no coatings or additives to perform well over time. The system operates entirely without power, using passive evaporative cooling to reduce internal heat. This is driven by air conditioning runoff - water that’s already being produced in cities but usually wasted. By redirecting this water into Holo’s reservoir, the design takes advantage of a consistent, overlooked resource.

In winter, when AC systems are inactive, the same reservoir becomes an insulating air pocket, showing how the design adapts to seasonal change without any need for active control systems. By incorporating a water pool Holo provides local fauna with water source in the dry summer months. The planter integration increases the thermal mass and provides habitat value beyond the nesting birds,  supporting invertebrates and native vegetation in spaces that might otherwise remain bare. The design also encourages behavioural change, raising awareness about the effects of heat on local wildlife and showing how small changes to infrastructure can have broader ecological benefits. Holo is a practical, scalable example of how circular thinking can be applied to conservation in urban environments.