Mr Finlayson also said he was setting a portion of funds in the regional museums policy for capital construction projects aside into the next financial year "in expectation that your proposal will be fully developed in the near future".
The next round of council meetings is in late January and it hopes to have Mr Finlayson in Wanganui for that round.
The gallery has a very low earthquake rating and, because of that, immediate steps are being taken to move staff out of the building.
To that end, councillors agreed to a budget of not more than $180,000 for a double relocatable classroom-type building on the grassed area immediately behind the gallery.
It will be used by staff and as education space for students.
The other option being looked at in more detail by council officers is either the lease or purchase of a building on Taupo Quay to provide temporary premises for the Sarjeant, until the existing gallery is strengthened and extended.
That has been estimated at about $2.8 million, with funds coming from the newly struck earthquake strengthening rate.
But councillors want legal advice on whether or not that special rate can be used that way before proceeding.
They also want chief executive Kevin Ross to look at other options of underwriting any fundraising for the major Sarjeant project, so it does not fall on the Wanganui community.