A proposal to create a exclusion zone along a West Coast fault line is rattling affected businesses.

The Westland District Council has proposed a plan change along a fault line through Franz Josef, under which new builds would have to meet more vigorous standards.

That's upset those already in the proposed zone, who have told a hearings panel the properties will be effectively red-zoned.

But Council Manager for Planning, Community and Environment Jim Ebenhoh says they don't see it that way.

"We see it as a necessary risk mitigation. People can still maintain their buildings, upgrade and modernise etc, we just don't want to see taller buildings."

Jim Ebenhoh says everyone got to say their piece on the proposal.

"Independent commissioners will produce a report within the next 15 working days. That report will be binding on the council, however the decision can be appealed to the Environment Court, so we'll have to see what comes next."