About 1000 Inland Revenue staff will remain displaced for most of the year after an earthquake risk was discovered in their Wellington office building.
The government department closed its office at the Asteron Centre on Featherston St in July, forcing staff to work from home.
A new seismic assessment was commissioned when Inland Revenue sought to renew its lease there. It found the building had a lower earthquake rating than first thought.
Staff have since been temporarily relocated across several buildings in the city, including Ricoh House and the Freyberg Building.
Some staff are still working from home on some days- as was the case before Inland Revenue left the Asteron Centre.
Inland Revenue has confirmed it expects staff to be able to move back into the building by late this year following remediation work.
Commissioner Naomi Ferguson said they have been working to secure safe long-term accommodation for Inland Revenue in Wellington.
"We have explored a range of options and I'm really pleased that we will be able to return to the Asteron Centre.
"We are currently working through the timeframes around when we can return, as the landlord will need to do remedial work to address the seismic concerns with the building that prompted us to leave."
The Asteron Centre is Wellington's largest single office building at 48,000sq m.
It is 17 storeys high and features office space over 12 levels.
Ferguson acknowledged it has not been an easy time for staff who are now spread across different offices and that this would continue for a while yet.
"But I know that everyone will appreciate having certainty for our future Wellington accommodation."
The building is owned by Mark Dunajtschik.
A spokesperson for him, Nick Wareham, confirmed they expected the work to be completed by the end of the year, which will involve installing steel posts and plates at various locations.
He said the building would be strengthened to a minimum of 80 per cent of the New Building Standard.
PSA Te Pūkenga Here Tikanga Mahi National Secretary Kerry Davies said while members were looking forward to returning to the Asteron Centre, the union was pleased a solution has been found for them in the meantime.
"What's important about temporary work arrangements in situations like this is that the employer works with union delegates and staff to ensure that any negative impacts on staff are minimised – and so far it seems like IRD is managing this reasonably well."
Mojo coffee is located in the ground foyer of the building and has converted its offering to a pop-up café while there are fewer people on the premises.
Chief executive Pierre van Heerden said they still get regular walk-by customers from the central train station, as well as those who have stayed in the building and the surrounding area.
He said remedial work was being undertaken on other floors of the building and has not impacted Mojo's operations.
Van Heerden said the regular café space in the building was being used as a training centre.
"To train upcoming baristas and hospitality workers as well as increasing our own Mojo staff skills. We are focused on providing our customers excellent service, so training forms a big part of who we are as a company."
The Civil Aviation Authority is also committed to return to the Asteron Centre when remediation work is complete.
A spokesman said about 320 staff have worked both from home and in other spaces since July.
Anything below 34 per cent of the New Building Standard is considered earthquake-prone. A building's rating is determined by its weakest part, so even if the issue is localised, it still affects the site's overall score.
The issues identified at the Asteron Centre relate to the concrete floor, prompting the building to be considered potentially earthquake-prone.
The building has previously been advertised as being 100 per cent of the New Building Standard and the new rating has not been made public.