There was no evidence, the panel said, to suggest pre-1944 buildings were at any significant risk of demolition, relocation or areas were at risk of losing their character.
Sally Hughes, a spokeswoman for the Character Coalition - made up of 60 heritage and community groups - called the decision a bombshell for heritage and a win for the pro-development lobby.
"Clearly they have listened to all the submitters who are saying heritage is getting in the way of their development aspirations," she said.
An OECD report last month about New Zealand's economy said new heritage overlays stopping the redevelopment of land occupied by pre-1944 homes were among the blockages to more dense development on the Auckland isthmus.
The "interim guidance" is just that, and the council will have the final say on heritage rules when the panel makes final recommendations on the Unitary Plan, or planning rulebook for the city. This is likely to be towards the end of next year.