Auckland Council has stopped work on four or five house projects following an Environment Court decision affecting more than 400 home owners in the city's older suburbs.

The decision has left about 430 homeowners in limbo and having to reapply for resource consent for building projects in special character areas such as Ponsonby, Grey Lynn and Parnell.

Many of the building projects are renovations and alterations to villas and bungalows.

The uncertainty is greatest for 137 homeowners who have received building consent and may have started work. In their case, they may have to consult their architects and builders about possible changes or, worse still, stop work.

The problem stems from Auckland Council's Unitary Plan, which came into effect in November 2016 with new rules about what people can do to their homes in the city's character suburbs.

The plan created two sets of rules for "special character overlay areas" and the "single house zone" in the character suburbs.

The final wording was inconsistent and created some uncertainty over which set of rules should take precedence.

After taking legal advice, the council took the approach for 12 months that the special character areas overlay took precedence over the underlying single house zone rules. It also sought clarification from the Environment Court.

The Environment Court in an interim and final decision in March this year did not agree with the council's interpretation and ruled that both set of rules should apply when considering resource consents.

When the court made an interim decision in December last year, the council began considering both sets of rules.

Council regulatory director Penny Pirrit said what the decision means now is greater scrutiny of resource consents, which will require things like more input from neighbours.

Instead of just considering how character properties will look like from the street, the decision means the council must also consider wider amenity issues.

The council is aiming to write to all affected property owners over the next three weeks urging them to apply for a new resource consent, which will typically take two days. All costs will be met by council.

The council concedes that some of the home owners may not be granted consent when they re-apply.

Without a new resource consent, homeowners could face a judicial review to their existing consent.

For property owners who have started building work, the council strongly recommends they make the building works safe and weathertight and stop work until they have obtained legal advice and discussed their consent with council.

The council is in talks with the property owners where work has already stopped about possible compensation.

Council resource consent manager Ian Smallburn said some homeowners could be in limbo for some time.

A plan change to the Unitary Plan is being prepared to fix the problem.

Anyone who thinks they are affected can ring (021) 507-546 or email: [email protected]