Arlis/ANZ 2018 Conference News: Information about parking.
There is paid parking underneath the National Portrait Gallery.
Pricing information and directions are available here https://www.portrait.gov.au/content/parking
Paid parking is also available in the National Gallery of Australia underground carpark https://nga.gov.au/visiting/gettinghere.cfm
The rates are slightly cheaper at the NGA and it’s only a 5 minute walk to the Portrait Gallery.