The Challenge
The EME group (Ecologically Motivated Environments) is a design firm specialising in the built environment. The firm takes its environmental responsibilities seriously, employing a design process that places significant emphasis on the potential for ecological and socially sustainable outcomes in urban design.
The EME group is committed to designing residential, commercial, retail and school buildings that integrate water management, recycling and conservation, significantly reducing water usage and saving money.
The challenge is to encourage developers to instinctively incorporate water saving devices in residential design and to convince them of the positive benefits for both developer and resident.
The EME Group was awarded a Smart Water Fund grant to research rainwater harvesting with the goal of reducing household water usage by nearly two-thirds.
The research was applied to the design of four double storey townhouses in the Melbourne bay-side suburb of Brighton. The homes are a showcase of residential water conservation and recycling.
The Project
The Brighton ‘Eco’ townhouses are one of four new building designs developed by EME Group, that present practical actions that can be taken to save or reduce potable water consumption in the domestic environment. The target for the design project is a reduction in overall water consumption by 60 per cent.
The main water-saving feature of the buildings is a water harvesting system that collects water from the roof and surrounding garden and stores it for later use to flush toilets and water the garden.
The townhouses use the entire roof space, first floor decks, paved entry pathway and basement trap – a total of 575sqm – to collect water normally destined for stormwater drains. Inside, the homes are fitted with triple “A” rated water efficient devices including; low flow taps and shower heads; water recycling systems and underground water tanks that reduce reliance on mains water and relieve pressure on public stormwater systems.
The basement was designed to be larger than average to accommodate two 10,000 litre tanks in the basement car park.
Lessons Learnt
The design and demonstration of the “Eco” townhouses is part of a campaign to encourage all designers and builders to be more water efficient.
Storage tanks and water saving systems require extensive planning to ensure correct positioning, drainage and the most efficient use of a site. There are substantial savings to be made by integrating tanks into the original design of a building, compared with the cost of adding water-saving devices after the building is completed.
Sustainable building and water saving design are attractive features for high density living. The underground tanks in the basement car park allow the land to be maximised for living spaces, and the occupants of the site are reminded of the water saving features each time they enter the basement.
The Benefits
The water harvesting systems are expected to save 200,000 litres a year across the four town houses, in addition to savings from low flow devices. The up front cost of rain tanks and plumbing systems to support them are largely off-set by long term savings in utilities costs for the owner.
In addition, the developer was granted a concession by local council on the building-to-land ratio by trading the inclusion of sustainable building and water saving design for higher density development.
“I wanted to capture the 90 per cent of rain that falls in urban areas that ends up in drains and waterways, and put it to use around the house,” says EME Group Designer Luke Middleton.
“One of the biggest areas of water consumption around the house is the garden and the toilet. By using recycled water for these amenities we can significantly and positively reduce the amount of water wasted in households across Melbourne.”
