A $2.2 million renovation has put a 1960 Melbourne apartment block on track to become the country’s first energy-positive residential retrofit and cutting mains water consumption by more than one-third.
The Fitzroy renovation by impact investor Tripple, headed by cost $3500 a square metre and cut embodied carbon by 80 per cent compared with a knockdown rebuild
At a time when soaring costs make new projects – particularly multi-residential builds – unviable, the Wilam Ngarrang building retrofit shows quicker and cheaper renovations can improve the quality of housing and cut the emissions of the two-thirds of existing buildings that will still be here by 2050.
Melbourne had 70,000-odd “walk-up” medium-density public housing blocks, but the idea would also work for privately owned strata buildings of the same scale, said Ross Harding, the chief executive of Finding Infinity, the environmental consultancy working on the project.
“These buildings are reaching their end of their life,” Mr Harding told The Australian Financial Review.
“The cost to build new was, at a minimum – when we were doing it – $5000 per square metre. Now it’s upwards of that. We can retrofit these existing buildings, reduce embodied carbon by 80 per cent-plus and also not just fix them up, make them look prettier, but take them from the worst possible building you can find to something that is almost as good as you can get it.”
The $2.2 million retrofit meant a cost of about $150,000 per studio apartment.
“It was led with numbers and feasibility,” he said. “And the architects came into help us solve the problem.”
The work included repairing cancerous concrete, injecting insulation into the 50-millimetre-cavity between double brick walls, upgrading windows, making the building airtight and installing a 33kW rooftop solar system.
The hot water system was upgraded to include a heat pump and a new variable refrigerant flow heat recovery system connected to each apartment for efficient heating and cooling.
Rainwater collected off the roof was channelled into tanks and used for the new communal laundry and gardens.
The retrofit of the 1960 building saved 80 per cent of the embodied carbon of knocking down and rebuilding a new structure on the site.
Ok Mr Milgrom-Marabel said lessons from the project could be used more widely to preserve other walk-up buildings and avoid the common knockdown-and-rebuild alternative.
“The environmental cost of this would be devastating, but we would also lose the character of suburbs and the city,”
“This model shows an alternative that can save costs, improve outcomes for the people living there and the environment, and keep our city intact.”
Mr Harding said Melbourne alone had 1 million detached houses, multi-residential homes and commercial buildings that collectively wasted $4.5 billion a year due to inefficient use of energy.
Retrofits could cut the city’s emissions by more than 40 per cent.
Credit - Michael Bleby AFR