From the architect:
Our clients, Daryl and Natalie, engaged us to design a new home on a small suburban block in Hurstbridge, Melbourne. They were both passionate about creating a modest home representing their desire to live a healthy and environmentally conscious lifestyle. In particular, they wanted to explore all possibilities for going 'off-grid' in an urban context and using natural, reclaimed and locally sourced building materials.
With adult children leaving the nest, Daryl and Nat also wanted this to be their 'forever home' – one that best supported them to live independently into their old age.
The resulting 70 m2, single storey residence was designed as an innovative 'Earthship-inspired' solution. Rather than an Earthship style earth-filled tyre berm, the Urban Earth House was built into the existing north-facing, sloping landscape. Excavated site soil was re-used to build up the earth berm on the southern side of the house and also in the earth bag foundations.
A glasshouse was situated on the northern face of the house, enabling the sun to heat the concrete slab flooring and air on this side of the house. An air circulation system carries this warmth to the berm, so the earth herself lends a hand in maintaining a year-round comfortable temperature.
A reticulated water pipe system in the slab transfers heat from the north side to the back of the home achieving a consistent slab temperature.
Over time, we expect the combined thermal mass (insulated concrete slab, earth berm, gabion walls and water tanks) to stabilise internal temperatures at 21-23 degrees all year round. While our clients have yet to install their planned solar system, they've monitored their electricity usage over the past two years of living in the home.
They've achieved significant energy efficiencies, as the earth berm has gradually warmed, and they now report no longer needing to use electrical heating appliances during winter.*
This increased energy efficiency also means our clients will be able to purchase a smaller solar system, sized to meet their energy needs without having to cater for heating or cooling demands.
Privacy was achieved by installing glass only on the northern side of the house and optimising the uninterrupted views out onto a mature forested hillside.
Building a carport to the south of the house further shields the home from neighbours' view and makes practical use of an existing concrete slab.
Daryl and Natalie's desire for this home to support them to 'age in place', is threaded throughout our design response, examples include: smaller, easy to maintain living spaces, an accessible walk-in shower and one level layout with no need for stairs or steps.
The construction of this home ultimately became a vehicle for Daryl and Natalie to express themselves and to learn and share skills along the way.
Rather than dictating and controlling the construction process, we re-defined our role during this phase to act as facilitator and mentor. This flexibility lead to a several unique project outcomes:
- Helping our clients successfully stage community building workshops – tapping into local networks, we coordinated and booked out several volunteer workshops, enabling members of the public to 'learn-by-doing' how to build with natural materials (earth bags and mud bricks) *Please see workshop promo and images at the end of this submission.
- Supporting a woman with limited construction experience to project manage her own build – through listening, validating and 'guiding alongside', we assisted Natalie to quickly gain confidence and project management skills (she's now writing a book on her experience).
Daryl and Natalie also opened their home to 200+ visitors for the 2019 Sustainable House Day on 15 September and were recently featured in a local council video clip celebrating homes participating in this national event.
View the clip on Facebook.