Property owners hope the council will allow light, rural-residential development instead of imposing a 40-hectare minimum for lot sizes in the area as it rethinks land use south of its population centres.

The council's planning director Chris Berry said it would canvas changing the minimum on land within 5km of the border, but still preferred its proposed figure over any cuts.

Opponents to the plan, which would create a "buffer" on development between the ACT and NSW, are pushing for a cut to the minimum lot size to as low as 2.5 hectares.

Mr Berry expected the NSW planning department could oppose a reduction that large, as it opposed intense development along the border.

The council would need evidence to support a cut to the 40-hectare minimum, he said.

Landowners who formed opposition group "RU6 Dead Zone" met on Saturday following talks with the council, which they say hasn't informed the public enough about its plans.

RU6 Dead Zone, whose name refers to the area's proposed new zoning, has suggested a model of developing land in the buffer zone for rural-residential use that could include forming a consortium with the council, the ACT government and landowners as shareholders.

Group member Bill Ginn said property owners didn't want high density housing, but could manage their land better if lots were reduced from 40 hectares.

"It costs a lot of money to run a block of land that size," he said.

The group has asked the council to update the public about its plans, something Mr Berry said will happen early in the new year.

It wants to involve itself in planning for the border zone, telling members in a newsletter that "a proactive approach" could be more effective than waiting for Yass Valley Council to release a plan and invite comments.

However Mr Berry said it was likely to draft a plan before asking for feedback, and that any share in a consortium would raise governance issues.

The council wants to rezone the area by 2021-2022, and considers planning for growth further north a greater priority.

The buffer is designed to preserve the separate identities of Canberra and the Yass area, and to stop ACT development creeping over the border and into the valley's villages, Mr Berry says.

Opponents to the planned buffer zone have also complained about the exemption for the new suburb of Ginninderry, a joint venture between the ACT government and the Corkhill brothers to develop land on both sides of the border west of Belconnen, beside the Murrumbidgee River and Ginninderra Falls.