Eight months after its official opening, ASB's new corporate headquarters in Auckland's Wynyard Quarter has cut electricity and water consumption by half despite adding extra staff.
The secret, according to two of the bank's project members, is fresh air, careful engineering and design that reflects "collaborative, efficient and agile" habits.
A visit makes the meaning plain. Inside the airy seven-storey 20,000m² building, known as ASB North Wharf, over a thousand people shift in and out of meetings and between desks - at a ratio of about 75 work spaces for every 100 staff.
"There's no ownership of work stations," ASB head of strategic property projects Rod Aitken explains, sitting down for an interview alongside ASB head of property services Alan McKenzie.
Instead, employees choose a spot to suit the task at hand. There are 15 different options in each team's 'neighbourhood', from isolated booths to shared tables.
Gone are the filing cabinets and reams of paper that filled the old ASB Tower on Albert Street. After much scanning and shredding, nearly everything is now stored on the company's servers, which has made it possible to cut paper storage per person by about 80 per cent.
"That was a big barrier to get people on board," Aitken admits. "Once people got here, it's actually all worked out swimmingly well. We've got a good technology team."
Employees are offered either a tablet or a laptop and allocated a two-shelf locker, with doors coated in blackboard paint to double as a spot for kids' drawings during office visits.
The complex, built for ASB as part of its new 18-year lease with Kiwi Income Property Trust, cost $133.7m to develop and is valued at $162.2m.
It's hard to spot but occupant density has increased. "We've come down to about 11 square metres per person when fully occupied here," Aitken says. "We were at about 15, 16."
Operating costs are down from $135 to $95 per square metre compared to the ASB Tower. Gas and electricity consumption is down by 50 per cent per square metre and 60 per cent per person.
Natural lighting and ventilation is crucial. Green lights suspended over desks show when to open windows to improve cooling. Fresh air is drawn in and, as it warms, rises through a central glass atrium to a funnel on the roof, topped with a sail-like helioflek to bounce down light.
According to McKenzie, water consumption is down by half. A pebbled stretch of roof collects rainwater, which is used to flush the building's toilets. It's a visible improvement to efficiency - particularly when heavy rain stirs up sediment and tints the toilets' water.
Waste collection has also improved. All organic waste from the building is converted to compost and fertiliser and the bank's target is to divert at least 80 per cent of waste to recycling.
So what came first - going green or lowering costs? "It's a win-win," McKenzie says. "You're losing less power, less resources - and the spaces are better."
Like what you see? For weekly Element news sign up to our newsletter. We're also on Facebook and Twitter.