A new standard that targets methamphetamine-contaminated houses aims to guide landlords on testing and cleaning their properties.
Building and Construction Minister Dr Nick Smith said it was a "huge step forward" in helping home owners and tenants deal with the risks of meth contamination.
Smith said the most significant change was the 1.5μg/100cm2 limit, compared to 0.5μg/100cm2 under the old guidelines. He said the new standard resulted from a better understanding of the health risks.
"It will give people greater confidence and certainty, will result in hundreds fewer properties having to be vacated and save millions in unnecessary decontamination work."
Standards New Zealand manager Carmen Mak said the standard would make houses where meth had been found safer.
"Application of the standard will provide assurance that activities such as screening, sampling, testing, assessing, and decontamination of contaminated properties, and disposal of their contents, are carried out in accordance with good practice."