Consultant Maynard Marks is managing the project. Corbel Construction is the head contractor. Site offices are located in the middle of the townhouses in portable units.
Work began last November and is not expected to finish until well into next year.
Monolithic cladding had been stripped from exteriors and was being replaced by Nu-Wall, an aluminium-style cladding, a contractor said.
All rotting wood is being stripped out of the buildings and being replaced. Nu-Wall says it makes "an extruded aluminium weatherboard system which has been designed & developed in New Zealand and is manufactured locally".
Michael Rehm, body corporate chairman, said the entire project would cost at least $20m although it was estimated three years ago in a court document to cost $11.7m.
"We knew that opening up these buildings would be like a can of worms. There's a lot more damage than we ever expected because there's fire issues as well.
"None of this adds value to the owners but Auckland Council requires that the buildings be brought up to the current code. One of the things which bled us dry is time delays and every single day we had to wait cost us an extra $3000.
"I don't think people realise the fiscal damage done to projects like this," said Rehm adding that he was a rare owner/occupier.
"It's been a financial nightmare for me. I bought my place for $250,000 in 2006. Two years later, we found out it was leaky.
"I've spent already about $150,000 in repair levies and there's another one to go, probably another $60,000 to $70,000," Rehm said.
Most of the $20m was coming from owners who contributed 75 per cent and the rest came from the government's Financial Assistance Package, Rehm said.
About a quarter of the unit owners were borrowing money from the banks but the rest had to pay cash, he said.
"We all knew it was going to come. But three-quarters of the places are owned by investors. They look at it pragmatically. A lot of people will try to sell up at the end of it."
The original developers had sold their company and created a new company, Rehm said. No money was being paid by them "because no assets were easily attainable. Absolutely zero."
Ground rent was costing around $9000 for each unit annually he said "but that's nothing compared to where it's going to go".
In 2015, a decision from the High Court at Auckland described repairs: "Extensive work is required to the buildings. The estimated repair cost is $11.7m."
Tim Rainey of Rainey Law has acted for the owners who succeeded in getting a scheme of repair under the Unit Titles Act 2010.
The townhouses are on leasehold land owned by Ngati Whatua O Orakei Whai Rawa and that aspect has also caused issues. In 2011, Parnell Terraces' owners went to arbitration against the iwi over a long-running dispute on a ground rent increase.
On June 30, 2000 The Herald reported on Parnell Terraces' creation, calling it an affordable option.
"Parnell Terraces offers an entry-level opportunity to buy a two or three-bedroom terrace home, without giving up on quality, character and style, says Lindsay Kennedy of Broadway Developments.
"The 81 terraced-housing development, designed by Francis Clarke Architects, is being built at Quay Park on the northern side of The Strand and near the old Auckland Railway Station, recently converted to accommodation.
"Over the next six months it will be transformed into a new residential precinct. The Strand is within walking distance of the city, Parnell Rd cafes, Auckland University, and waterfront recreation. All the homes are over three levels and each has a private courtyard and deck."
In 2000, units sold from $194,000 to $210,000. The places have garages, some with parking for two vehicles.
Rehm is a senior lecturer in property at Auckland University who has written an academic paper on discounting cross-lease properties in Auckland and another wither other academics on the impacts of leaky homes and leaky building stigma on older homeowners.
Broadway Developments said neither board members Neil Hammil nor Lindsay Kennedy were available for comment.
Parnell Terraces was "an old, old project. It's not under way with us. Do you have the right company? Any directors involved all those years ago, they're basically retired," said a staffer.