This family's grand design needed to be extremely energy efficient - based on green principles devised by German environmental scientists.
For IT consultant Damien Lederer and his partner, patent lawyer Cristy Lederer, when it comes to energy efficiency, the suburban family homes being built throughout Australia don't quite cut it.
“Like every Australian, we don't like seeing resources wasted – but on a personal level, we begrudge paying huge electricity bills and huge gas bills, explains Cristy. The family bought a block of land in Coombs for $370,000 as the location was close to work for both Cristy and Damien. They then began designing and engineering the most efficient house they possibly could - a home that would use almost no energy to heat or cool.
Damien and Cristy wanted their new home to follow strict green principles set by the Passivhaus Institute in Germany. "Well we're building our dream house," says Damien. And I guess the primary goal is to make a very green house". The couple wanted their new home to be what's called a 'net zero energy' house, meaning the total amount of energy used by the building on an annual basis is roughly equal to the amount of renewable energy created on the site.
From the beginning, the project defied the norm. A specially insulated slab works to support an equally insulated structure. The walls themselves are made up of Structural Insulated panels both inside and out. They should in effect turn the house into a huge esky, meaning the family won't need heating during the cold winter months or cooling in the hot summers that Canberra endures.
Even the thin profile roof is made up of dense insulation clad in steel. Their hope is, all the effort made on the outside skin will help make comfortable what is essentially an open plan house - and one that features a stunning two-storey wall of west-facing glass.
The greatest challenging was in maintaining the open aesthetic along with the extreme energy efficiency. Two storeys of glass need a great deal of steel, which is not only a big expense but steel also soaks up the heat and can draw it inside. To manage this, Damien pulled the steel framing inside the house.
In the end, Cristy and Damien don't tick all the Passivhaus efficiency boxes, they were able to build to an impressive green standard for the suburbs, and almost stick to their original budget of just $600,000 too.