People building a Hebel house may have to pay more, but they are getting their money's worth when it comes to sustainability, warmth and coolness, according to ecobuilder Chris Naylor.
The full Hebel system had been designed to make the most of available heating and cooling, and made for ideal homes where extremes of temperature are experienced, he said.
Mr Naylor is constructing a full Hebel house at Lower Manorburn with 350mm-thick outside walls and 150mm-thick inside walls.
The aerated concrete block is held in place with threaded rod tie-downs. Mr Naylor said the block had a high insulation value with a high amount of mass to store heat.
The blocks could be plastered inside and out, and while it was quite a bit more expensive to build with them, the quality was much higher, Mr Naylor said.
"You have a full masonry house, and that will last better than other types of housing."
A disadvantage was the fact that the product had to be imported from Australia in containers.
"It's not a standard system and industry is not really geared towards that, as this type of house requires specialist fixing," Mr Naylor said.
• Wonder blocks
- Hebel block is concrete block with cellular construction.
- Weighs one-third of a similar-sized concrete block.
- Has increased thermal mass to retain heat for long periods.
- Is its own insulation.
- Outer-wall blocks 300mm thick have higher rating than fibreglass batts for insulation.
- Ease of construction - do-it-yourself builders can erect a house.
- All internal walls are block, creating more thermal mass for heating.
- Fire-proof.
- Blocks are plastered over on the outside and can be painted, plastered or have wall linings attached on the inside.
