Are eco-buildings commercially sensible, or just a lot of hot air? asks Chris Barton.

The view through floor to ceiling glass is mediated by rows of vertical fins, some deliberately set obliquely, to stop the sun's glare. But the filtered vista from the seventh floor of ASB's new North Wharf headquarters across a shimmering harbour to the Waitemata's iconic island is still quintessential Auckland.

"This is what we call a boathouse, which is a common space. No one is assigned to it and anyone can use it," says ASB property general manager Derek Shortt. "You can work out why it's called the Rangitoto boathouse. All the decor up here is in the Rangitoto colour theme to bring it into this space." This is the era when Westpac turned one of its branches into a beach. No bankers in speedos, however.

Shortt is selling a sustainability story. The bank wants to reduce its carbon footprint by 25 per cent by the end of the year. When completed in June the building promises to deliver both significant savings and a healthier workplace.

"We are looking to reduce our overall operating cost probably by 40-50 per cent in this building compared to other commercial buildings," he says.


"Sustainability is not just about a building. It's important everything we do on a daily basis gives consideration to not only the environment, but our people and those that we work with."

Fine words - especially considering sustainability, a central plank of the previous Labour government's agenda, has largely been expunged from the current government's vocabulary. National has also retreated from Labour's 2007 mandate for a minimum 4 to 5 Green Star rating for all new government office buildings. "This government has been very clear about mandatory rating," says Green Building Council chief executive Alex Cutler. "They are not interested in imposing any mandatory rating that will, on what they perceive, disadvantage the market." The market rules.

Then there's the just announced retreat from the Kyoto protocol and any sort of leadership role in reducing New Zealand's carbon emissions. Hot Topic blogger Gareth Renowden described the abandonment as completing "the National-led government's programme of gutting and dismembering the climate policies it inherited from the last Labour-led government when it took power in 2008."

In the face of such a wholesale retreat by government, it's ironic that corporate organisations like the ASB seem more committed than ever to the concept of sustainability. Corporates also seem on a different page to government with regard to taking responsibility for reducing their carbon footprint. In a booklet about its new building the bank writes: "For us, sustainability means aiming to make the right decisions every day, and taking responsibility for the effect we have on our stakeholders and the environment we work and live in, now and in the future."

It sounds admirable, but is green building hype just that - hot air? At ASB North Wharf both hot and fresh air are intertwined themes of the sustainable narrative. Standing on scaffolding in the funnel-shaped thermal chimney which draws the building's hot air up through vast open atria to expel it to the outside, one gets a sense of how the building will deliver on its promise.

"This is the cone that allows us to dispense air from the building," says Shortt. "Above us is a glass roof and sitting above that is the reflector that helps to bring light from the outside down into this space and to cascade that light throughout the building."

The building's distinctive shape is apparently meant to mimic Auckland's volcanic landscape. Some see other things. Herald columnist Brian Rudman observed that the building appeared to be "topped by a giant, meringue-shaped, seagull dropping". Auckland City councillor Sandra Coney said "the much vaunted turban top" lacked grace.

From the outside the thermal chimney appears as a mal-proportioned louvred cube perched atop a cone-like roof. By opening louvres on the opposite sides to the prevailing wind, the cube creates a pressure differential to suck hot air to the outside. But the building also takes fresh air in - through its state-of-the-art "displacement" air conditioning system, and via a decidedly lower tech method signalled by "traffic lights" on each floor. "If the red light is on, we don't open. If the green light is on staff will know we can open the windows and the perimeter displacement bins will have been turned off so no air conditioning is coming up."


But while cost savings certainly provide a rationale for green office buildings, the health and productivity benefits that come with the influx of fresh air and daylight into pleasing work spaces also play their part. A seventh floor barbecue deck with expansive harbour views and something called activity-based working take such notions to a new level.

"We provide a selection of spaces for our staff to work from," says Shortt. The 1400 people housed there can move around "neighbourhoods" and select an area that suits their work needs for the day. Those who want to be alone and highly focused might choose a "cockpit" cubicle with a closed door. Or, if their work is more collaborative, they may opt for the "ear chair" or "reflection lounge" furniture. In between is an array of booths, workbenches and desk settings to cater to every need. There are other boathouses too, mostly on the third floor - "City" and "Container", one with "aquapods" for meeting and "The Deck" cafe at the foot of the building's snaking open staircase.

Though the building houses one of the more opaque industries, transparency is a prevailing theme. Floor levels are open to each other via circulation spaces. "You are seeing people throughout the space and you are mixing with those people all the time," says Shortt. He's talking about social sustainability - design that delivers "soft" benefits such as less time off, less staff churn and increased productivity.

ASB is the anchor tenant of the 21,000sq m building, having taken out an 18-year lease for 19,500sq m of the two interconnected blocks, one six and the other seven storeys, that make up the complex. Level two will have 97 carparks and the ground floor will have 1500sq m of retail space.

Surprisingly, the building is yet to get a Green Building Council Green Star rating, although building owner Kiwi Income Property Trust will seek one when it is completed. The owner is aiming for 5 Green Stars. Why not six? Shortt says he expects the built rating to fall just short of 6 Green Stars - probably around 5.75. "For us to get from 5.75 to 6 is $500,000-$600,000. The economics of that are not worth it."

Going green costs. But in the context of the building's total price tag - $131 million for the base build and around $200 million all up with the fit-out - it's hard to understand why such a landmark example of sustainable design didn't go for broke.

The first building in New Zealand to get 6 Green Stars, the top level in the rating system, was Samson Corporation's Geyser building in Parnell. Adapted from the Australian Green Star rating system, the system here evaluates projects against eight environmental impact categories such as energy and water use, indoor environment quality and materials.

"The brief to our architect was we wanted a non-air conditioned, green-rated office building with a central courtyard and tenancies of various sizes to cater for most of the business sizes in New Zealand," says Samson Corporation's Marco Creemers, pointing out that 86 per cent of businesses employ six people or fewer.

The most significant feature is its double skin glass facade, creating an air gap between the two skins which is used to both passively heat and cool the building. Other features to gain Green Star points include low-energy sensor-controlled lighting, staff bicycle storage and showering facilities, rain water collection and reuse in bathroom flushing and irrigation, "Hungry Bins" for composting organic waste, and car stacking machines which enable cars to be parked in a smaller basement space that doesn't need lighting or air conditioning.

But even with all these features, the building was still coming up a few points short of 6 Stars during the design phase. The solution was to introduce a small internal courtyard into the floor plan of the largest building in the complex, providing extra fresh air ventilation. Creemers says the green features added 7 per cent to the cost of the build but points out that the payback through energy savings is seven to 10 years. The building claims to use 27 per cent of the energy of a typical retail/office building of its size. That equates to around $90,000 of electricity a year for common areas in the standard building, whereas Geyser, when it's fully tenanted, is expected to cost just $30,000.

"Tenants make immediate savings, not to mention they can reduce their company's carbon footprint straight away by being in a building that doesn't waste energy. So they are making ethical decisions," says Creemers. "We have a green lease, so you have to commit to green philosophies. You have to recycle and if you are doing a fit-out you have to use sustainable materials."

Walking the talk, Samson Corporation has taken up residence. "We have moved our business from an air conditioned building into this natural environment and we have noticed a huge difference with our staff," says Creemers. "You feel much better and also people are more self-regulating. In an air conditioned environment you have always got this constant battle with people too hot and too cold and people keep adjusting the heating. You can't really do that in green building. You have got to adjust yourself."

From this developer's point of view, sustainable building makes good business sense. "We take a long term view. We like building assets that will be around for generations," says Creemers. "We always design for a recession. When you've got this building to choose from and a standard building that maximises the floor area of the site, and one is giving you more amenity that the other, which one are you going to choose for the same rent?"

Creemers says the Green Star rating, despite being expensive, bureaucratic and heavy on paperwork, provides a useful service. "It's the only means in New Zealand where you can compare buildings." But he'd like to see a greater emphasis on the "as built" rather than the design rating. "There is a lot of misrepresentation. The 'as built' rating proves you've got the same rating as your design. It is a lot more difficult to get."

The Green Building Council's Cutler says the membership organisation, which provides training for Green Star accredited professionals used in the assessment process, has recently reduced compliance costs by 25 per cent. "We try to encourage an integrated design approach which means you are getting everyone around the table from the beginning," she says. 'It's difficult to retrofit Green Star into a design."

Cutler points to the Green Property Investment Index, announced last week by the Property Council and research company IPD, as proof of concept. Based on 16 buildings worth $1.3 billion, the index shows that office buildings with a Green Star rating returned 8.9 per cent in the year to September 2012, outperforming non-rated buildings, which returned 6.4 per cent.

Rated buildings showed a stronger net income ($366/sq m compared to $358/sq m for non-rated buildings), indicating stronger demand for green rated assets. Rated buildings also had a greater capital growth component and lower capitalisation rates, indicating less investment risk.

"Even though it's only 16 buildings, it proves what we have been talking about," says Cutler. "It comes down to a fundamental understanding of sustainability - that it isn't just about tree hugging. There actually is an economic imperative in there."

The index is yet to gauge operational expenditure effects - a process which will be assisted when the Council, with the Energy Efficiency and Conservation Authority, launches a New Zealand energy rating adapted from the National Australian Built Environment Rating System (NABERS) in March. The rating tool measures a building's operational energy and water efficiency, indoor environmental quality and waste recovery, and is mandatory in Australia for office space covering more than 2000sq m.

At the 5 Green Star NZI Centre on Auckland's Fanshawe St, which has been occupied since late 2009, Lincoln Fraser knows just how valuable measuring energy use can be. The development director for building owner Newcrest has just completed a programme of fine tuning the displacement air conditioning system. Like ASB North Wharf's system, it reverses conventional air conditioning by bringing in chilled air at the floor level - typically at 16C to 18C - which then rises as it warms and is extracted via fans at the top of the building's open atrium space.

The system has an immediate advantage over conventional ceiling air conditioning, which has to drive much colder air - typically at 8C-10C - downwards to cool a space. It can also take advantage of the outside air temperature. "Think about how often Auckland's air is 16-18 degrees," says Fraser. "We did the graph when we first started looking at this and we just took these huge chunks of the year and translated them through to free cooling."

By fine tuning the system - so the building's two chillers don't automatically turn on to full capacity when there are small temperature changes - Fraser says landlord electricity costs have been reduced by a further 25 per cent over a 10-month period. "We are taking it from a building that was already punching well above its weight in terms of energy consumption, to a new level," he says. "If you look at the amount of energy it's using per person, it's in the realm of a building that doesn't have air conditioning."

A key aspect of the NZI Centre's efficiency comes from the number of people it gets into the space - currently 780 - equating to around 13sq m per person. The building was originally designed to accommodate about 600. "I'm delighted the building has been able to support that number without failure," says Jasmax lead architect Tim Hooson.

Like ASB's new headquarters and Geyser, floor to ceiling glass brings an abundance of daylight into the building, which penetrates further than normal thanks to a higher floor to ceiling height and all floors being open to the vast vertical atrium space. The north face, like Geyser, features a double skin facade, in this instance with an automated blind between the two glass skins. Light sensors control the blind, which opens and retracts automatically depending on the light level during the day and closes at night. The space between the skins also exploits the chimney effect - hot air rising - to limit the sun's heat warming the building.

But undoubtedly the greenest aspect of the NZI centre are the plants growing throughout the building, their roots encased below the raised floor which houses the ducting of the air conditioning system. "We decided to go with the story that this building is so green that the plants are growing out of the floor," says Hooson. "It became this idea that if the plants are growing well and healthy then we [the occupants] will be growing well and healthy too."

The building also has a green roof, a communal deck BBQ area for staff planted with sedums. As well as helping filter rain water for collection, it earned one point on its Green Star rating because it allowed the building "to absorb up to 1.3 tonnes of carbon dioxide per year" and provided "870 Kg of oxygen into the local environment per year." By now a number of green building themes are apparent - open atrium spaces, transparency, natural ventilation, plenty of fresh air and daylight, and double skin facades.

But does it all add up? "New Zealand is probably the climate in the world for low energy design," says eCubed Building Workshop director Dave Fullbrook. "It doesn't get too hot and it doesn't get too cold." He says the overriding argument for green building is future-proofing. "The cost to actually future-proof a building is relatively low. To get a reasonable level of performance - equivalent to a 5 Green Star building - you're talking about a 5 per cent premium. The payback might be seven years."

Fullbrook's company produced a report in 2007 for the Ministry for the Environment on the case for Green Star rated government office tenancy fit-outs. The overall finding was that central government, as the most significant owner and lessee of commercial buildings in New Zealand, could have a significant impact if it adopted 4 and 5 Star ratings for its buildings over the next 10 years.

Estimated outcomes included an energy cost reduction of $5.8 million a year and an annual energy use reduction of 38.7GWh.

For 5 Star landmark buildings the study found a 52.5 per cent reduction in both energy use and cost, and a 57 per cent reduction in water use and cost.

The findings are consistent with international studies, except that the premium for going green is higher in New Zealand than elsewhere. A recent analysis using the US LEED rating system found that LEED rated buildings cost on average 2 per cent more than non-rated buildings. The higher premium here may be explained by New Zealand's relatively slow uptake of sustainable building practices - something Fullbrook is concerned may have stalled with the government's exit from a leadership role in mandating minimum green standards. He's disappointed, too, at the missed opportunity to require sustainability in the Christchurch rebuild.

Ecubed has also done post-occupancy analysis on the 5 Star Meridian building in Wellington, looking at soft cost productivity benefits. The study used questionnaires to test staff perceptions of building performance before and after moving into the new building. "They were on a roughly minus 5 per cent productivity rating before moving in. When we re-measured [for the new building] they were plus 10 per cent so it was a 15 per cent productivity gain." Fullbrook says such cost benefits are realised mostly in reduced staff sickness and staff retention costs.

He says the Green Star ratings, although relatively expensive - about $100,000 for an average sort of build - provide useful quality assurance and have acted as a switch to put the industry on the path to green buildings. "There is a second switch that is coming into the market which is the cost of energy generation from photovoltaic solar panels now significantly reduced in price," says Fullbrook. "For the first time, the cost of putting photovoltaic panels on a roof is a 10 year payback." He says such systems connected to the electricity grid make it feasible for buildings to have zero net energy use.

For French architect Edouard Francois, the current obsession with energy savings detracts from a full appreciation of sustainability. "It is the first step in arriving at a real ecologic process," he says "But it is something very boring because it kills your ethic." For Francois, who was in Auckland last month, sustainability is much more than various star rating rules, some of which, he says, are totally silly.

"You need to have a context attitude - to make something that fits totally in the place," he says. "That means you take care about the place and the landscape where you build. When you do that you take care about the climate, and the geography. You take care about how to build and the process in relation to local values and the local materials. This is a sustainable attitude."

Francois, the father of green facades, disrupts conventional notions of sustainability through his architecture. Many of his early buildings, like the Flower Tower in Paris, with giant flower pots on the balconies planted with bamboo, literally disappear behind a wall of green, as though nature is claiming it back.

Another is the Chateau de Lez in Montpellier - the "building that grows", constructed of local rock loosely compacted in wire cages which are infiltrated with plants that will eventually bloom and cover the entire rock face.

Francois disrupts in other ways too. In another building, he expressed the softness of insulation by putting it on the outside and covering it with a thin membrane of polyolefin, a polymer more commonly used for shrinkwrap or moulded flexible foam, which is waterproof and recyclable. In his Hotel Fouquet in Paris, he adorned some of the walls with a delicate fretwork of 8000 aluminium tree branches. "That is an evocation of forest. It is probably the first facade you could totally recycle," he says casually, meaning the aluminium branches could easily be taken off and melted down to reclaim their cost.

The city of Paris has commissioned Francois to build a residential tower block - the first in 40 years. Like much of his work it will be covered in greenery, in this case an enormous range of wild plants from forests around Paris carefully selected by botanists. The idea is that the building will be a prolific pollinator. "The wind will spread the seeds everywhere - a new corridor for the birds and plants. This is the building for biodiversity in Paris."

Francois' rationale for cladding the building in a titanium skin is that it's a precious material like gold and therefore highly sustainable. "Nobody throws gold into the rubbish." He has an economic argument too. "The titanium comes from China and we don't know if in the future we can have that because they are going to block titanium - there are a lot of very important materials for the economy that probably will be blocked by the Chinese." For this reason the building is a "temporary stockage (storage) of a ultra-sensitive material for the economy."

For Francois, the arrival of sustainable thinking in the 1990s, since accelerated by the global financial crisis, signals a replacement of modernity. Modern values such as internationalism, hygiene, ideas of eternity, abstraction and technology give way to new organising values of context, the ephemeral, the human, emotion and the local. Sustainable ideas, he says, that are permeating everything.

"In cooking you see quite a lot of the values that are important now. The question of where does the food come from speaks about geography, about local values, about seasons and health," he says. "All that is linked to architecture - how to do a building that is economic, taking care of local values, to fit in a place. How to build with the sentiment of taking care of our health."