That means delivering sustainable, durable homes that minimise the use of energy and water use. It means designing buildings that are warm and dry, as well as features that provide fresh air and daylight to enhance the comfort and wellbeing of the people that live there. This will improve health and environmental outcomes and reduce electricity and water bills.
The solution
Fletcher Living took up a challenge in 2021 to pilot the design and build of a low carbon home. The key aim was to minimise the carbon emissions associated with the build and operation, from the materials used through to its energy and water use over a 90-year lifetime.
The first Low Carbon ‘LowCO’ homes are a three-bedroom detached home and three-unit terraced home block that will be built in 2023 at the Waiata Shores development in Auckland. The project will combine off-site manufacture and traditional construction methods to minimise emissions.
Taking a whole ecosystem approach was key during the design phase. This meant investigating factors such as the site’s geography, ground conditions, and the impacts on the landscape and biodiversity. The team also considered the optimal size and orientation of the house, the systems for power, water and wastewater and considered heating, cooling and moisture control based on the local climate to deliver on the low carbon goals.
The energy, water and green technologies in LowCO represent industry best practice in passive house building and landscape design. Passive housing standards focus on maximising the components and materials of the building to achieve a healthy home that delivers on all aspects of the occupants’ wellbeing while consuming very little energy. This can help reduce capital and operational costs and reduce carbon emissions.
Carbon emissions associated with the LowCO home will be about seven times less than a standard build. It has been designed for high performance and thermal efficiency. Products and materials have been selected based on minimal energy use during their processing, manufacture and transportation. Using solar panels, the home will maximise the use of renewable energy. Over a year the house will use about 450kWh of electricity for space heating to keep it at 20˚C all day, every day. That’s about a third of the power typically used for heating in a standard built home.
The pilot is looking to achieve an ambitious water use target of 75 litres per person per day. That’s well below the New Zealand average of 220 litres per person per day. Through a collaborative partnership with Watercare, the design team is finding ways to reduce water use and wastewater disposal. The home will have systems to capture and store rainwater.
Benefits
LowCO is an ambitious pilot that reimagines how we will build houses in Aotearoa New Zealand in the future. The data driven modelling approach used in the design phase has demonstrated we can significantly reduce whole of life emissions and operational water use by considering the lifetime impact of our homes at the outset.
The pilot will collect and analyse building performance data once the homes have been built by using digitally connected meters and sensors. Knowing the water and electricity used to run a shower, for example, can help improve how people use these resources in their homes.
LowCO offers a glimpse into what it will take to achieve future industry standards and the value of modern methods of construction and offsite manufacture. The pilot is also revealing the need for more New Zealand-sourced sustainable products, new supply chain models and sector capability-building. This will be necessary to shift from one-off bespoke builds to low emission sustainable homes that can be built easily at an affordable cost.
Business/organisation name: Fletcher Living
Project: LowCO - Low carbon homes pilot
Owner: Fletcher Residential Limited
Architect: Architype Limited
Engineer: Sustainable Engineering Ltd
Date of completion: FY24
