Christchurch homes with asbestos concealed by earthquake repairs could be sold without the buyer being aware the hazardous subtance is present.
The Earthquake Commission (EQC) estimates 43,000 Christchurch homes due for quake repairs could contain asbestos.
In about 10 per cent of cases, asbestos in ceilings will be "encased" behind plasterboard instead of being removed during quake repairs.
Homeowners are not obliged to inform potential buyers about the presence of asbestos in their property.
Canterbury District Health Board medical officer of health Alistair Humphrey and Christchurch homeowners have called for asbestos finds to be recorded on council land reports.
Humphrey said a public register should be kept.
"If someone's just fixed a ceiling where there's been some damage to the asbestos tiles and [contractors] have covered it over, that I believe should go on the LIM (land informational memorandum), but in practice that doesn't happen and it's not likely to happen."
It was unlikely homeowners would want to disclose the fact because they "might perceive it would devalue their homes", he said.
EQC spokesman Iain Butler said the commission advised homeowners and contractors working with asbestos, but was not required to notify other authorities.
A record of properties containing asbestos was kept for internal reporting purposes.
"We would be able to, theoretically, get that information, but to my knowledge we've had no requests to do that," he said.
A St Martins homeowner, who did want to be named, had asbestos contained in her ceiling during quake repairs about six months ago. The buyers of similar homes should be notified, she said.
"It gives people the choice, whether they think they're bothered or not."
A Richmond homeowner whose ceiling had tested positive for asbestos said it would be "selfish and irresponsible" to hide the fact when selling the house.
"If it's there, I think it's fair that people know about it. That's just wrong and passing your problem on to someone else," she said.
"This is a real health hazard. This is our house, we own it and it's our responsibility."
Harcourts South Island provincial manager, Jim Davis, said real estate agents had to inform potential buyers of asbestos, but homeowners did not.
"We are obliged to tell purchasers when there are aspects of the house that would be relevant to them and could be a concern. Asbestos fits into that category. When we know there is asbestos then, in my opinion, that should be disclosed to a potential purchaser," he said.
Christchurch City Council customer and support manager Tracey Weston said homeowners were not obliged to put asbestos on their LIM.
"It is not a legislative requirement for council to proactively seek out this information," she said.
However, asbestos would be included on a LIM at the owner's request if they had documentation as proof, Weston said.
- The Press