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Six Green Star rating for Auckland University building – with Beca
Waipapa Taumata Rau University of Auckland's recent achievement of a world-leading six Green Star design rating for the redevelopment of its Social Sciences building is an inspirational example of team innovation and collaboration led by an aspirational client vision towards net zero carbon.
Green Star is a holistic approach to building design spanning the whole process from design to construction to the handover from the construction to the operations team. The six Green Star rating recognises the university’s B201 building redevelopment as world-leading in performance and environmental impact. The New Zealand Green Building Council (NZGBC) manages this formal process whereby a third party assessor awards points across various credits to rate a building’s performance and environmental impact.
The story of how the redevelopment went down this track is enlightening and encouraging. Ultimately, it shows achieving a high Green Star rating needn’t be as difficult or costly as perhaps assumed.
Digital render of the finished building
Pushing the sustainability envelope
The journey began with a fit-out project that quickly morphed into a whole building refurbishment and an aspiration to achieve a six Green Star rating. Beca’s Associate Environmentally Sustainable Design Engineer Timothy Howarth says the university had been on a significant sustainable buildings’ journey for many years and was already well aligned for a five Green Star rating for the project. Confident that this rating was achievable, the university asked the project team to push for a six Green Star rating.
Richard Walsh, Technical Director of Building Services at Beca, says engineering consultants are in a position to uncover opportunities in building design that can lead to more sustainable outcomes. They can support clients with their sustainability journey and help them to navigate their unique constraints, without necessarily hiking the cost. He says, for example, changing the specs of carpets to have low volatile organic compounds (VOCs) doesn’t necessarily cost more, and that, with this focus, you’re going in the right direction and helping change the industry.
Significant challenges were presented because this was an adaptive reuse project. However, because of this, the Green Star focus resulted in an overall additional cost of approximately only three to five per cent more than a business-as-usual (BAU) project. The NZGBC collects data on how much a Green Star rating costs a project with one of its credits identifying where an uplift in cost occurs. Tim says a sustainable design will score well and incur a little additional cost, whereas shifting the baseline towards the greener end of the spectrum in a less sustainable design can be costly.
The initiation point for this project was when the university took a longer term view looking past the initial fit-out project towards what more it could do with the building. Discussion soon focused on adaptive reuse - giving the building a new heart, lungs and facade. The need to bring the education and social work faculty into the city as soon as possible created a programme pressure, which ultimately was the real driver. However, this was closely aligned with the university’s sustainability aspirations and the natural progression with Green Star.
Sustainable features and alternative materials
Sustainability is visual and hidden in this design. From targeted carbon fibre strengthening to suspended lighting, a green roof, solar panels, soaring timber-clad atrium, and rainwater harvesting, there is much to shout about.
The photovoltaic solar panels covering half the east building’s roof and some of the atrium are a standout and important visual and sustainable addition. They provide the very visible sustainable features as well as generating up to 10 percent of the building’s operational energy. Their impact will also be enhanced with information screens within the building detailing daily energy generation and savings.
Suspended ceiling lighting is also a notable feature as it pushes the boundaries of commercial lighting design. There are two types of lighting design. One designs for function and the second, utilised in this building, designs for people. Tim says this latter biological lighting design highlights the vertical and horizontal surfaces, almost simulating the brightness of the outdoors, and creates a more comfortable and attractive environment for the building’s inhabitants. This lighting is a departure from the university’s design standards, but one it was enthusiastic to try, and Tim says the results will be intriguing. It was an additional cost to the usual BAU, even in the high-efficiency environment that the university resides in.
Another exciting feature is the use of carbon fibre strengthening in the adaptive reuse of the building. A very lightweight, high-strength, innovative material perhaps best known for its use in America’s Cup boats, it was a valuable component in the building’s seismic strengthening. Peter Beazley, Manager of Auckland Structures at Beca, says using carbon fibre allowed the team to modify the old building to make it easier for people to move around in. New connections between levels such as lifts and stairs, or doorways through structural walls, weaken a building. Using carbon fibre to tie it back together removed the need for more costly and carbon-creating additions. As Peter says, carbon fibre fabric was glued to the concrete surface to give it extra strength. He likens it to “very large and strong bandaids on the concrete walls and floors”.
A further prominent feature is the dramatic glue-laminated timber roof in the atrium encapsulating the huge volume of the space that was developed in close collaboration with the project architect, JASMAX, and the builder, Hawkins.
Big hitters in carbon reduction
A structure is the biggest offender in a life cycle assessment, which looks at the total carbon emitted by a building or infrastructure. Reusing a structure is even more sustainable than building with mass timber, with the most sustainable building, notes Peter, “[being] one that you don’t have to build in the first place”.
In this project, the reuse of the 1970s concrete frame primary structure, and Peter’s team’s seismic upgrade, resulted in huge upfront carbon reduction and gave the building an additional 50-year-design life. One of the Green Star credits relates to how this reuse occurred and the analysis techniques used to maximise the potential of the frame from a seismic perspective. Peter says it’s easy to take a conservative view of seismic capacity, but his team took it further to understand how the building was likely to behave when subjected to increasing seismic loads. One of the key moves was to replace the building’s original heavy façade with a new lightweight, high-performance one. The reduction in weight reduced seismic loads and therefore provided an opportunity for new additions, such as the huge plant room on the roof, which will be used to run a variety of ventilation systems. This clever reuse of the primary structure had the biggest impact, says Tim.
Following this, much thought was given to the procurement of products and materials, including the assessment of material impacts using Environmental Product Declarations (EPDs). EPDs demonstrate a commitment to environmental responsibility and transparency and are an independent environmental assessment and verification of products and services aligned to international standards. They enable comparison of like products, including the ability to choose the lowest impact product in terms of carpet, wall paint, ceiling tiles, concrete and steel. Although it is early days in the carbon journey, and the upfront carbon from the procurement and construction of materials employed remains, EPDs encourage carbon mitigation and use of the best products available at the time. And, although some products will inevitably cost more, this isn’t a given, says Richard.
The design also considered whether products had eco labels, which are third party, independently certified, and therefore best in class. Within this framework, the design looked at products that were low pollutant and had low indoor emissions, such as VOCs in paint, carpets, adhesive and formaldehyde in engineered timber, to provide the highest indoor quality possible for the building’s future inhabitants.
Operational and embodied carbon
Peter points out that everything that goes into a building is considered not only from a carbon perspective, but also for the occupants’ wellbeing and the environment. Operational carbon concerns, for example, the energy used to power ventilation systems and lighting, and the associated carbon emissions resulting from electricity consumption. The operational carbon emissions make up approximately half of the building’s overall life cycle carbon emissions.
The embodied carbon emissions, which include the upfront, in-use and end-of-life stages of a building, make up the other half of the life cycle carbon emissions. Carpet is an example of embodied carbon emissions. Carbon is emitted upfront for its manufacture and installation, and further carbon is emitted in-use as the carpet wears out and requires replacing a couple of times during the building’s life cycle.
Brownfield projects often involve multiple structural challenges and this one was no exception. Big decisions were made during the design phase about which approach to take and Peter’s team had to rely on its judgement and experience to assess and manage the risks. At early stages the dominant risk regarding the original structure was the uncertainty of the ‘as-built’ situation. This risk was reduced as the build progressed and detailed surveys could be completed.
Peter says the trickiest areas involved connecting the new, contemporary additions to the existing building because of the variability and uncertainty of the interface when compared to a new build.
Lighting also provided a challenge because it veered away from the standard recessed fittings towards suspended lighting, which is rare in commercial offices and institutional public buildings. As Tim points out, you might see suspended lights in a hotel lobby, but the remaining lighting is often recessed.
A further and ongoing challenge is the airtightness aspiration for the building. As far as Beca is aware, it will be the first commercial building in New Zealand to be tested for airtightness. Expertise has been sought from Australia because New Zealand doesn’t have airtightness regulations for large commercial buildings, unlike Europe, North America and Australia. However, this has presented logistical challenges for the main contractor and applied pressure to the programme with the additional activities associated with the air pressure testing. Tim says education and learning are essential for success in this area, but that the additional effort is worthwhile because airtightness is linked to energy efficiency and reducing energy consumption in a building.
Green Gorilla and Nikau, the companies responsible for the project’s waste disposal, gained their environmental certification during this project. This represents a notable industry shift in the treatment of waste in line with carbon emission reduction. The project required the companies to have this certification as part of the project’s Green Star rating, and, to date, 92 per cent of the waste generated has been diverted from landfill. Tim says anything over 90 per cent is very rare.
The stormwater management of the building has also been designed to be environmentally sustainable. The basement contains a rainwater storage facility, which will provide water for toilet flushing, and a rubbish room enabling the segregation of the building’s waste products, including glass, paper and compost.
Social impact of the build process
Another positive impact of this project was its focus on contractors’ well-being. The construction industry is historically known for its high-stress and high-pressure environment so a key initiative of this project was prioritising contractors’ physical and mental well-being. Consequently, Hawkins, the main contractor, gained a Mates in Construction site accreditation based on the provision of mental health support and suicide awareness training. Few are aware that fatality from suicide in the construction sector is 10 times higher than from work-related accidents. Other initiatives included White Ribbon seminars (an organisation focusing on the prevention of domestic violence), health and nutrition education, as well as lunchtime talks and sporting events between the consulting and contracting teams. All of these initiatives help to improve relationships between teams, including conflict resolution. The focus was on improving the level of contractor support in the construction industry and Tim hopes the main contractors involved in the project will continue to roll it out in future projects without requiring the encouragement of a Green Star project.
Long-term economic benefits
The long-term economic benefits are wide-ranging. Richard says the operational costs will be lower because of the building’s design, and, as well as the improved mental and physical well-being of those involved in the project, the finished build will provide a welcoming working environment benefiting those teaching and studying. The benefits are far-reaching and cross generations.
Advice for those interested in designing for sustainability
Tim believes projects with a sustainable and Green Star focus will get easier the more they’re undertaken. The goal is to make them BAU. Ideally, sustainability specialists will become redundant, he says, because everyone will employ this focus and consequently move the construction industry in the right direction.
On an encouraging note, Tim says the construction industry, depending on the field, already has a sustainability focus and does it well. Green Star helps to prioritise some of these initiatives, bringing them to the forefront of a project. The industry needs a spotlight to raise awareness of what is happening because it is not good at storytelling or celebrating these projects and achievements. He says the current focus in New Zealand and internationally is on life cycle assessments. Therefore, with an increased understanding of the upfront, embodied and operational carbon in a project, comes the knowledge and ability to reduce carbon and align projects with a country’s net zero carbon goals. Green Star is a tool to help measure progress towards those targets.
When taking a long-term view of investments, operational aspects can dominate capital aspects, says Peter. An example is solar panels, which are a big investment upfront, but there’s a payback in approximately 10 years.
Richard encourages those who traditionally focus on the short term to consider the benefits of sustainable design. For example, if developers have a building that is six Green Star rated and has low operational costs, it will be desirable to prospective tenants and rent can be maximised. He believes, depending on the industry, that people are drawn to sustainable design, including those who will inhabit the building. Having a world-leading Green Star building is a huge drawcard for the university, which needs to attract its clients, the students. It is also a drawcard for the students who are wide-eyed on the environment and the future.
Challenge to industry regarding environmental and social governance
Sitting alongside the Green Star tool is environmental and social governance (ESG). ESG is largely what Green Star addresses holistically. Tim says many organisations set ESG goals but they often come unstuck when trying to achieve them. He believes Green Star can help measure and track progress, which is the purpose of the ESG principles. For example, depending on what is prioritised, Green Star can help an organisation focus on climate change and reducing environmental emissions, or on social aspects, including diversity, cultural heritage and supply chains. Governance, which includes leadership and accountability, can also be prioritised through these tools and certificates, and this affords transparency showing a business is doing what it claims.
Journeying with the client
The push for a six Green Star rating was instigated by the university and demonstrates its commitment to sustainability. Being brave and risk-aware is essential when going on the Green Star journey, says Peter. He considers a vital component in helping support and encourage clients in this space is to bring all the risks to the forefront. This allows for more control and a combined understanding for the client and consultant teams early on in the project.
It is also critical for all parties to be able to challenge each other, and collaborate and brainstorm together, around the sustainability requirements, to achieve the best outcomes for the wider business and the specific project, says Tim. It’s about going on a collective journey to understand what amazing can look like and the broader outcomes that may be possible along that journey.
Peter says there are numerous good, compelling and commercial reasons to work on sustainability, rather than doing sustainability for sustainability’s sake. He says it’s about doing what you do well, creating efficient solutions, and looking for win-win situations where you can create a step change.
The strength of the relationship between the university, Beca, and the entire project team, meant that everyone involved was willing to work together to do something different and achieve a better outcome within budget, to create a world-leading sustainable design. Consequently, the project journeyed towards, and achieved its six Green Star design rating ambition.