A reduction of 50% in carbon emissions from 2006 standards, while more than meeting an individual's personal Kyoto target (requiring a 60% reduction from 1990 levels by 2050) still doesn't meet the brief for a zero carbon house.
The BaleHaus® has an additional feature however that allows it to become a carbon “bank”. Straw and timber are renewable resources that can provide a continuous renewable supply of building material, replacing high embodied energy (i.e. “CO2 generating”) materials such as steel and concrete. As straw and timber grow they absorb CO2 through photosynthesis, keep the carbon atom to make cellulose and give the oxygen atoms back to atmosphere. This is how we “bank” the carbon into the structure and fabric of each BaleHaus® .
This process “banks” the equivalent of 42 tonnes of CO2 per house to deliver a less than Zero Carbon Home before any one moves in. Even allowing for the ca 20 tonnes of CO2 emitted during manufacture, supply and installation of the building fabric, structure, fixtures, fittings decoration mechanical and electrical equipment, this still leaves 22 tonnes of carbon dioxide in the “bank”.
This “carbon credit” is enough to offset 10 years of BaleHaus® energy requirements using fossil fuels and over 40 years if energy is supplied from renewable, grid-based sources.