Is untreated timber equivalent to H1.1 for use in framing?

Untreated kiln dried pine should not be regarded as equivalent to H1.1 treated framing.

H1.1 timber specification covers additional protection against insect attack and H1.2 should be used if H1.1 timber is not available.

NZS 3602:2003 does specify a number of instances where kiln dried untreated framing can be used as an alternative to H1.1, but untreated wood should not be used unless specifically allowed.

The understanding is though, that the standards will be changing very soon, and kiln dried untreated timber will be excluded from most of the areas that it is currently permitted in.

It is also likely that the H1.1 specification will also be removed completely and that timber treated to the H1.2 specification will be the minimum requirement for almost all radiate pine framed houses.

More information on Wood Preservation and the Hazard classes

Also read What is a Hazard Class?