Bill Culbert (1935–2019) and Ralph Hotere (1931–2013) are senior New Zealand artists. In 1991, these old friends begin producing collaborative works, juxtaposing signature elements from their work as individuals. Their collaborations have a bicultural dimension—Hotere is Māori, Culbert Pākehā. Permanently installed in the Gallery’s neo-classical facade, Fault is their largest joint work.

Fault (1994) is a conversation between Hotere's ‘black windows’ and Culbert’s fluorescent tubes—darkness and light. The artists blacken the front windows and install two lines of fluorescent tubes, dividing the windows, spanning the facade. Fault refers to Wellington, which is located on an earthquake fault line. It also suggests the relation between Māori and Pākehā—perhaps aligned, but certainly not parallel.

The artists say they want to challenge traditional definitions of what public artwork can be. Fault becomes part of the environment, rather than distracting the eye. 'Fault is an integral component of the architecture of the building’, says Director, Paula Savage. Reviewer, Keith Stewart agrees, saying Fault ‘is a part and apart’. '

Fault is commissioned by Scollay Holdings through the Wellington City Council Arts Bonus scheme. With a few interruptions—most significantly for nine months in 2009, while the Gallery was closed for earthquake strengthening—it operates continuously. It runs 24/7, but looks best by night. It draws about as much electricity as a two-bar heater.