Desert Rose House: University of Wollongong’s Highly Sustainable Smart Home Designed for the Elderly

A 200-strong team of students from University of Wollongong (UOW) and TAFE NSW built a user-centred home developed for the Solar Decathlon Middle East 2018 held in Dubai.

In 2018, the team placed second only to Virginia Tech in the global competition and, this year, has taken home an Australian Engineering Excellence Award 2020.

The decathlon requires contestants to design and construct a fully-functional home and then compete based on 10 criteria including architecture, engineering & construction, energy efficiency, sustainability and innovation.

The highly sustainable smart home developed by Team UOW was named after ‘an iconic flower that flourishes in challenging environments’: a desert rose. It was designed to function sustainably by exploiting Dubai’s extreme climate.

“It’s the Formula One of houses,” says associate research fellow and project manager for Team UOW, Clayton McDowell, “the temperature control is more stringent than your fridge.”

Desert Rose House was first constructed in Australia before being   dismantled and shipped to Dubai in sections and then reassembled as part of the competition. Its high-tech features include automation, mobile phone control, energy efficient HVAC systems, water usage monitoring, Internet of Things (IoT) sensors, voice controlled fittings such as lights, windows & taps, solar panels, two batteries for power storage and an electric car charging station.

A range of students from almost every faculty of UOW and TAFE, ranging from engineers, nurses, plumbers and chefs, participated in the competition, which McDowell described as one of the most challenging things he has ever done.

The decathlon judges contestants based on 7 primary pillars: sustainability, future, innovation, clean energy, mobility, smart solutions, and happiness.

Throughout the course of the competition (except during daily tours), the house was required to maintain a stringent internal temperature of between 23-25°C with relative humidity of 35-60% during the up-to-30°C Dubai days. Energy performance was then measured to assess the house’s ability to maintain this temperature. 

The house is designed to minimise thermal loads through passive design such as thermal massing, an airtight membrane wrapped around the house and triple-glazed windows with microshade technology (angled shading built into the glass).

The Desert Rose uses an innovative HVAC system, designed by Team UOW, that includes phase change material tanks (phase change material refers to substances that release/absorb energy as they change in state between gas, liquid or solid). These act as thermal batteries to store cool energy collected during the night and then are used during the middle of the day to drive the fan coil units instead of using the heat pump. This substantially reduces the energy used by the HVAC system during peak load.

Power generation is undertaken almost entirely off-grid using 104 Building Integrated Photovoltaic Thermal (BIPVT) solar panels (‘building integrated’ means the panels also act as the roof cladding) and 13.6kWh of battery storage - enough to power the house for a whole day. 

Underneath the solar panels are water pipes with the dual purpose of cooling the solar panels (improving their efficiency) and heating the water for use as domestic hot water.

To optimise energy efficiency, Team UOW developed something called Model Predictive Control (MPC). MPC creates prediction models for both power usage and solar generation for the following 24 hours. Using this data, an algorithm determines the optimal charging and discharging schedule of the battery, ensuring as much solar energy is used as possible.

For example, if the occupant uses more power in the evening, the optimisation algorithm will ensure maximum battery charge for that time and then charge the batteries in the morning whilst energy consumption is lower.

Greywater from the house is treated through a vertical-flow filtration system composed of gravel and sand layers. 

“Unlike most systems, once the water passes through, it is recirculated by a pump through the filtration system several times. This allowed us to downsize the area needed by around 90% compared to a typical treatment system,” says McDowell.

The outer skin of the external wall is made by a specially-made lightweight foam concrete that uses recycled glass and carbon fibre mesh.

“The combination of the mesh and glass resulted in a 40% reduction in cement required versus a conventional foamed concrete wall.”

More than sustainability

In addition to the smart and sustainable features of the house, the team decided to go above and beyond the competition brief and speak to a higher social purpose. They realised that the competition was a great opportunity to educate and advocate for an issue affecting 47 million people globally: dementia.

“Dementia is our second highest killer, and yet it is still taboo in many cultures. Our goal was to shine a light on the topic and bring attention to the ways we can design smarter to consider the needs of people living with dementia,” says McDowell.

The team conducted intensive research to identify the most important design considerations that would provide a higher quality of life for people living with dementia. This included an interior design that prioritised line-of-sight so occupants can better navigate the house.

“Every component we used had research behind it,” says McDowell. “But it was important we didn’t automate too much. We still wanted occupants to be able to enjoy their independence, such as being able to get up in the morning and open the blinds themselves.”

The level of thought given to every detail of Desert Rose House is immense. The taps use Electronic Thermostatic Mixing Valves (ETMVs) which means the temperature of the water can be set from your mobile phone, and the taps illuminate and change colour to indicate water temperature. 

Cupboard shelves have been designed as wheelchair-friendly so they can be accessed easily from a sitting position. And the structural frame has even been designed to accommodate a retrofitted handrail.

“The house was designed to adapt to the needs of occupants as they age and support independent living. Not only does this increase the quality of life for the occupant but also reduces the burden on aged care services at the same time,” explains McDowell.

As part of their research, the team spoke to people living with dementia and sought input from one the world’s leading dementia researchers, UOW professor, and executive director of Dementia Training Australia, Prof. Richard Flemming.

Why aren’t we building this way?

McDowell says that the industry’s fear of the unknown is the biggest barrier preventing adoption of the design and build principles implemented by Desert Rose House.

“Most would say cost is the biggest barrier, but I don’t think that’s the case - the industry is scared of change.”

McDowell says that the project was never intended to be commercialised but was created as an ongoing research project or a ‘living laboratory’.

“Ultimately, winning the competition wasn’t our main goal. Our main goal was to advocate for independent living, and inspire the global community to think more laterally about home design.”

The project is open source so all the research, designs, products and information on the house is available online here.

“We created Desert House because we want to change the way the world views homes for the elderly and create a movement that considers the ageing population and allows them to live a life of enjoyment in the comfort of their own home for as long as possible.”