Standards New Zealand has raised the safe limit of Meth contamination in residential housing to 1.5 micrograms per 100cm squared - up from 0.5.
The standard covers what it calls acceptable levels of methamphetamine residue in bedrooms, living areas, kitchens, sheds and garages following decontamination of an affected property.
First National Real Estate CEO Bob Brereton compares the Meth situation to the leaky home syndrome saying contaminated properties will likely sell for less than a comparable "clean" property.
He says any level of Meth or P residue in a home should be disclosed to potential purchasers by real estate agents.
The Meth problem is now so widespread that buyers should carry out their own tests before agreeing to buy a property.