In a nod to its heritage, the old corrugated iron roof was kept and a new roof installed over the top with insulation between.
"Keeping these remnants of the industrial history of this area lends a certain authenticity to it," Johnston said.
The building has no Heritage NZ status, nor is it scheduled on Auckland Council's district plan, therefore has no legal historic status, but Waterfront Auckland thought it important to retain.
An adjoining building was demolished to make way for the east-west new Lysaght Lane, which will in turn link into a new north-south laneway.
Johnston said Lysaght office workers would be able to work from that pedestrianised laneway which has a central landscaped rainwater garden feature.
"Workplaces are about blurred, collaborative spaces."
The council-owned Waterfront Auckland paid for the $6 million upgrade and Khong said it was taking a lead role in showing how restoration could be done sympathetically and with environmental aspects in mind to achieve a 5-star Greenstar rating. Sustainable features include louvres and sliding doors for natural ventilation, an energy monitoring system and a waste sorting room.
Showers and lockers have been installed to encourage tenants to run or bike to work.
Materials removed from the block were sent to a Waterfront Auckland salvage site for repurposing.
A 900sq m mezzanine floor, with seismic strengthening properties, has been added to expand the building which is now 1800sq m.
All services are at the western end, meaning each of the two floors is entirely open. Australian hardwood ironbark gantry beams, roof trusses and columns are a big visual feature.
Khong said Waterfront Auckland had leased the building to Auckland Tourism, Events and Economic Development which would in turn sub-let to tenants, probably in the IT sector.
The building will be ready to occupy by around August or September.
Dodd said the internal space from ground floor to ceiling was 9m, so each of the two floors have big stud heights. Cabling and services are suspended from the roof. Original windows were lowered to give greater visibility for the worker inside and pedestrians outside.
The original entrance canopy above the main Pakenham St entry, which was once used as a loading dock, has been retained but new glazed pivoted door access is being installed.
"The fitout will maintain the view through to Lysaght Lane beyond," Dodd said. "This project has retained the character of the original industrial building while future proofing its structure. The refurbishment design is fitting for place and purpose."
Hunter said one of the job's most challenging aspects was the site contamination, discovered when new 800mm piles were sunk.
"The contaminant was Blue Billie, a byproduct from the old gas works and it appears in the soil as brilliant blue. We were not aware at the start this was a contaminated site, which brought with it restrictions and slowed the building process down."
Dodd said historical material showed the building was built for John Lysaght of Bristol, London, and Wolverhampton. That business was a galvanised, corrugated iron, and wire netting manufacturer and its logo was an orb iron block, still clearly visible alongside the firm's name on its main Pakenham St frontage.
Lysaght upgrade
• Ex-industrial warehouse, now offices
• Corner Halsey/Pakenham Sts, Wynyard Quarter
• Now owned by Waterfront Auckland
• $6 million upgrade nearing completion
• Architects: Warren & Mahoney
• Builder: Canam Construction.
