Answers to the city council's mould-ridden, leaking building problem might take a while to surface into the public domain.

That's the message from Project Clean manager Terry Wynyard, who admits the overall picture surrounding the Willow Street HQ is taking a while to emerge.

Mould inside Tauranga City Council's building. Photo: Steve Morris.

Terry was once the city council environmental services manager – the department responsible for food licences, building consents and environmental engineering.

He's now co-ordinating the council's response to the leaks and stachybotrys mould which has emptied city hall of most of its employees.

Prendos consultants are handing over the first of the reports on the buildings on Wednesday afternoon.

'They have completed the technical part of the report,” explains Terry, 'but they haven't quite completed the quantities and the costings for the work that they are recommending.

'So I'm waiting for them to do that.”

The contents of the reports will be discussed at a workshop meeting with the council's executive staff, and he expects to get it to the councillors by mid-May.

'We are not just looking at the leaks in isolation,” says Terry, 'we are looking at what else has to be done to the buildings from a seismic, strengthening point of view as well. So everything goes in the mix.”

Beca is working on the seismic strengthening reports which, once presented, will be peer reviewed.

Decisions about the way forward, and whether to move nearly 300 staff back into a repaired and strengthened building or demolish and rebuild, won't be made until the information is available.

Terry adds: 'We don't know yet, and that's some time away before we take that to the elected members to make a decision on.

'Hopefully, in a week or two, we will be able to give more accurate times.

'It's quite a process. It's not like the private sector where if you have a building that's got a problem and you have the money to fix it, you get on and fix it.

'In local government you have a lot of processes to work through, including procurement, which can be quite time consuming.”

Tauranga City Councillors are already setting money aside for a situation now expected to cost millions more than the $1,376,332 it has cost so far.

The $1 million rates surplus has gone into the building contingency fund.

Council also recently approved committed and known mould costs for the 2015/16 and 2016/17 financial years of $1,053,424 per annum, and an additional $1 million per year for potential future council campus building costs.

A building contingency reserve is also required, which will require a further allocation of $794,318 from 2017/18.

The four buildings on the council campus have all leaked for years, and additions made in the early 2000s did not halt the leaks.

The administration building at the Hamilton Street end of the block was completed in 1972, with an enclosed canopy entranceway extension added in 1994 and a single-storey extension onto Willow Street and Hamilton Street in 1998.

Leaks were discovered in July 1998 where the single-storey extension joined the original building and on the outer edge of this extension.

More leaks occurred in the administration building and the civic buildings in 2005 as a result of a 'weather bomb' storm. After that, the extent and frequency of leaks has been more than minor.

The ground and first floors of the civic buildings were completed in June 1989, and the first leaks reported the following March. From then onwards, there were continuing reports of leaks, wet carpets and mould.

The cause has been variously blamed on the construction of the roof-top car-park, the air-bridges, the arcade roof plus windows and joinery. The leaks continued in spite of remedial work undertaken by the original builder.

Leaks, mould and health concerns forced the first evacuation of staff from the first floor of the Wharf/Willow Street civic building for three months in 2003, while a thorough cleansing process took place.

The latest evacuation of staff from the building was on December 15, 2014, when 219 city council workers were moved out.