Inland Revenue has closed its central Wellington office and sent up to 1000 staff home after a new seismic assessment found the building had a lower earthquake rating than first thought.
The government department said it commissioned a full detailed seismic assessment of the Asteron Centre on Featherston St when it was looking to renew its lease there.
But the new assessment has put the building at a lower rating than previously assessed.
It's unclear whether the building is earthquake prone, which is anything below 34 per cent of the New Building Standard (NBS), or whether the rating is above that threshold but still too low for Inland Revenue's standards.
Inland Revenue occupies seven floors of the building, with up to 1000 staff based there.
"Staff will work from home as they did during the Covid-19 lockdown last year," Inland Revenue said in a statement.
"This will be the case until a remediation plan to bring the building up to standard is in place."
No decisions on the long-term use of the building have been made, nor on Inland Revenue's future Wellington accommodation.
The Civil Aviation Authority (CAA), which also occupies the building, confirmed it has received a copy of the seismic report that indicated some "localised areas of concern".
A spokesperson said the primary structure was above 100 per cent NBS and the building could still be occupied.
However, after discussing the report, CAA's leadership team decided staff will work from home for the next two days.
This is so the current information can be further assessed and CAA can seek independent advice.
An update will be provided to staff on Friday afternoon and normal services will be provided via phone and email, the spokesperson said.
The Asteron Centre is Wellington's largest single office building at 48,000 sq m.
It is 17 storeys high and features office space over 12 levels.
Suncorp New Zealand executive general manager of people & culture Catherine Dixon said Asteron Life employees have also been told to work from home.
"While we understand that the building is deemed safe to continue to work in, the safety of our people is the highest priority so we are taking a conservative approach while we get further advice.
"We already have flexible work arrangements in place and many of our employees regularly work from home at least some of the time and are well equipped to do so at short notice."
Asteron Centre owner Mark Dunajtschik said he has no comment to make on the situation and referred questions to Inland Revenue.