Built on a plot measuring just 5 x 4 metres and set over three floors with a roof garden, this innovative dwelling and workplace was developed to demonstrate and encourage discussion around how to achieve sustainable living and healthy densification in a city.
History of the 5×4 Project
Ralph Alphonso, the project manager and owner builder, had developed several town houses in inner-city Melbourne, Victoria and decided to see if he could fit a house into a alley way that was previously filled by a shed. He used the One Planet Living framework to ensure that the whole lifecycle of the house – from conception to eventual decommissioning many decades from now – would be done in an environmentally responsible manner. While maintaining high sustainability standards, his compact and ingenious home does not compromise on style, comfort or mod cons.
This is the first time that One Planet Living has been applied in detail to a single home and demonstrates the flexibility of the framework. Conceived and driven by Ralph’s desire to push the existing envelope, the entire project has been documented and all of the designs, processes and materials have been shared to showcase, demonstrate and inform about achieving sustainable construction.
- Zero Carbon – meets net zero carbon standards with electricity-generating photovoltaic solar panels generating 3,000 kWh/year
- Sustainable Water – rainwater collection for garden irrigation and toilet flushing
- Sustainable Food – with 11m2 of growing space, Ralph is already growing chilies, herbs and strawberries and is investigating the potential for vegetable production
- Sustainable Materials – offcuts from locally harvested and sawn hardwoods, which would normally have been turned into woodchip, have instead been made into laminate timber used throughout the building
- Culture and Community – four public events per year to be held at the house per year for people to share the construction journey
- Health and Happiness – a shady rooftop garden and hot-tub with great views over nearby downtown Melbourne!
Big sustainability ambitions, clever design
Zero carbon in use….To help keep it warm in winter and cool during Melbourne’s fierce summer heat, this is a well-sealed, super-insulated house which uses phase-change materials in the walls. They turn from liquid to solid as the building warms and cools, absorbing heat when it heats up and releasing it when it cools down. When Ralph’s home is sealed off from the exterior heat or cold, mechanical ventilation with heat recovery keeps the air inside fresh.
Even so, the house requires some heating in the winter months and some cooling in summer by blowing warmed or cooled air through the home. This relies on an electrically powered ground-source heat pump with twin boreholes extending 65 metres below the house to circulate water through the pump. In summer the heat pump sheds the heat generated from cooling the house below the ground while in winter it uses the abundant low grade heat in the earth to warm the 5×4 home.
Over the year, the electricity generated by the photovoltaic panels (with 4 kilowatt peak output) should more than cover Ralph’s total electricity consumption. The home has high efficiency electrical appliances and lighting throughout.
Water saving…Living in water-stressed Victoria state, Ralph wants to cut his water use below 90 litres a day, compared to a Victoria standard of 150 litres per person a day. His home uses low flush toilets and highly water-efficient appliances, but the biggest saving in tapwater consumption comes from harvesting rainwater from the large roof of the next door house (which he had also built earlier on). Rainwater is perfectly good for toilet flushing, washing clothes and watering plants.
Low carbon footprint from construction…The 5×4 home’s structural beams, floors and ceilings, walls, window surrounds, stairs and furniture are all made from sustainably-sourced timber, reducing the building’s carbon footprint and making it a carbon store. Much of that wood consists of laminates; short pieces of wood left over from sawing which have then been glued together in thin layers to make a very strong and attractive building material. And it comes from sustainably managed hardwood forests in Victoria. There is a hefty concrete floor slab at the base of the house and some concrete blockwork on the bottom floor, but these use concrete with much lower carbon footprint than standard concrete.
Growing food, providing green space…despite being on a tiny, inner city site, one facade of the 5×4 house is festooned in greenery, including herbs, fruits and vegetables. The upper two floors and the roof garden have large external window boxes with an automatic irrigation system which uses stored rainwater.
What did it cost?
Ralph estimates the building cost 300,000 Australian dollars. To that should be added about AUD 100,000 for the cost of his labour – he built much of it himself – and AUD 60,000 worth of support from a wide range of suppliers of services, materials and equipment. That takes the total to around AUD 460,000 (£212,000). However, the completed house, just outside Melbourne’s central business district, has been valued at AUD 800,000 (£374,000).
Ralph, who has been living in the 5×4 home since its completion in June 2015, reports that all the sustainability features are working well. Its performance will be extensively monitored. The project is in the process of updating its One Planet Action Plan, which covers both the development of the building as well as Ralph’s journey as an ‘accidental environmentalist’. As part of several research projects, the 5×4 project offers valuable examples of One Planet Living in practice and will continue to promote the possibilities for sustainable construction and lifestyles.
It was also featured on Grand Designs Australia.
About the Developer
Ralph Alphonso was the project manager and owner builder of this project. He drew on his experiences from his production company, Barley Store, which delivers a broad range of design-based projects, spanning the fields of photography, the built environment and multi-media. Its approach is to identify creative projects and challenge existing responses.
He brought together a range of specialists to support construction, who contributed expertise on a range of topics including design and engineering, energy, air and water, landscaping, timber and lighting.