3 things to know about building a straw bale house

1

There are no NZ building standards for straw bale constructions There aren't a lot of straw bale homes in NZ and no official building standards, other than those all houses must meet under the Building Act (2004). Natural home architect Graeme North has spent decades lobbying and helping to create building standards for natural homes. He says there's one crucial thing to know about building with straw bale in NZ's humid climate.

“A strawbale building must be designed and constructed in such a manner that the straw always remains dry throughout the entire building process and the lifetime of the building.”

The Earth Building Association of NZ (EBANZ) recommends getting an experienced designer to do an analysis when applying for a building permit, as different councils have different requirements.

“The construction detailing and plaster coatings make or break straw bale construction," says Graeme.

Read more: www.earthbuilding.org.nz/strawbale/

2 They’re not for everyone

Keeping the straw dry is crucial; if it gets wet, it tends to compost instead of drying out. Straw bale construction doesn't suit a site that gets high winds and heavy rainfall. Even in a good location, the design will need well-designed flashings around windows, doors, and corners, and wide eaves around the roofline to help protect it from moisture. The plaster coating must be well-maintained and occasionally reapplied as it will crack over time.

3 2 things most straw bale homes need

While straw bales can be load-bearing, most homes have a timber framework to give the structure more bracing, and meet earthquake and wind standards. They also tend to have concrete floors for the same reason.