Advocates of green building are gaining traction in Christchurch, with betterment in energy performance and earthquake resilience a key feature across commercial, residential and civic development projects.
The projects include the first post-quake 5 Star Green Star commercial building, the Awly Investments building.
Designed by architects Warren and Mahoney, with sustainability consulting services provided by BECA, the five-storey mixed use development comprises three linked buildings and is due for completion in early 2016.
Sustainability initiatives include a high-performance facade with solar-control glazing and external shading and a highly efficient air conditioning system.
To improve seismic resilience, it has base isolators in the structure that reduce swaying and shaking, and diagonal seismic bracing for lateral stability. The bracing is visible through the building façade, making “an architectural statement that this building belongs to a more structurally robust, post-earthquake city,” according to the New Zealand Green Building Council.
NZGBC chief executive Alex Cutler said that in the aftermath of the earthquakes, the idea of rebuilding sustainably was often put in the “too-hard basket”. However, Ms Cutler said, because green buildings delivered good returns for owners and provided attractive environments for tenants, they were a vital part of drawing businesses back to the central city.
“This Green Star rating is a milestone in the rebuild process, and it’s great to see a developer recognising that sustainability is an investment worth making,” Ms Cutler said.
Anna Yeo, a director of Awly Investments, the developers and owners of the building, said a high rating green building was important to the company because it wanted to help create a sustainable future for Christchurch.
“We wanted to create an exceptional, uncompromising building, and we feel that the award is recognition of this. We want to provide a building of which our tenants can be proud and that will work for them to provide cost efficiencies,” Ms Yeo said.
In addition to a well-insulated thermal envelope, other energy-saving features of the building include LED lighting and occupant sensors throughout, good solar orientation and internal floorplates that maximise natural light for occupants. The linked buildings also have an internal courtyard with green spaces.
Colliers International office leasing specialist Helen Weideman is managing leasing of the building and is already in negotiation with several parties.
Ms Weidman said the owner wanted to set a new benchmark for premium buildings in Christchurch.
“Green buildings are starting to come back onto the agenda in Christchurch and tenants are increasingly interested in the efficiencies that they offer. The owners of the Awly building are long term investors and having a sustainable building is important to them,” she said.
Custom Green Star tools aim to encourage betterment
There has been one other Green Star rating awarded in Christchurch since the quakes. The $55 million Forte Health surgical hospital opened in February 2014 and gained a 4-Star Green Star rating using a custom tool. It was the first health facility in New Zealand to achieve Green Star certification.
There have also been four custom tools commissioned by the Central Christchurch Development Unit for Anchor projects including the Bus Interchange, Convention Centre Precinct, Stadium and Metro Sports Facility.
“CCDU is conscious of minimising environmental impacts while rebuilding the city and finding sustainable ways to undertake the work,” CCDU director Warwick Isaacs said.
“Using the Green Star tools will guide the project teams’ use of sustainable and environmentally-sound methods, from design right through to construction and practical completion.
“We want the projects to leave as small an impression on the environment as possible.”
Ms Cutler said the NZGBC appreciated that it was hard for developers to consider sustainability when there were so many other issues to navigate in the rebuild.
“However, long-term Christchurch would benefit massively from buildings that are optimal for both people and the environment. Although this is well-recognised by residents and business, putting it into practice hasn’t been easy. We hope CCDU’s use of Green Star will help others see the benefit, and that it doesn’t necessarily have to be a costly exercise.”
BASE shows just how cost-effective green building is
The NZGBC has developed an introductory-level green building assessment tool, BASE, specifically for smaller rebuild projects in the city.
The standards for energy, water, waste, indoor environment quality and materials selection have been set so that use of the tool will deliver a “moderate increase in green building practices over standard industry practice and Building Code requirements,” the NZGBC stated.
An assessment by BECA of the outcome of using BASE to benchmark projects showed a 20 per cent reduction in operating costs due to reduced energy and water use.
Quantity surveyors Davis Langdon analysed the capital cost impact of building to BASE standards and found it would add 1.3 per cent to the cost of a 1500 square metre building and 0.5 per cent to the cost of a 3750 m2 building.
Estimated payback periods based on the energy savings ranged from 2.4 to 4.6 years for the larger building type and 5.9-11.4 for the smaller building.
To date, three rebuild projects have achieved BASE certification: the retail and commercial office redevelopment of Knox Plaza; the Unimed Building, a commercial office rebuild; and Cashel Square, a mixed retail and commercial project.
The NZGBC told The Fifth Estate that because projects didn’t register until completion, while it is aware anecdotally that many project designers were using BASE, there had not been a substantial number of registrations yet. Another factor is that smaller projects tended to be happening later on in the rebuild process than larger ones, the NZGBC said.
10 star residential projects demonstrate how easy it is to do better
In the residential sector, two demonstration homes in Addington designed and developed by architect Bob Burnett have achieved a 9 Star Homestar rating for design and are set to achieve 10 out of 10 stars on completion. This makes them some of the most sustainable homes in New Zealand.
Mr Burnett told The Fifth Estate the homes were also designed to be affordable housing and provide a model for other home building projects across the country. He said affordable housing in New Zealand sat in the $400,000 to $600,000 price bracket, depending on location.
The two-storey and single storey homes both incorporate solar photovoltaic panels on the roof, with battery storage installed for the two-storey house.
The buildings have highly insulated and well-sealed building envelopes, with a ridged air barrier cladding on the exterior, laminated veneer lumber for the framing, high performance argon-filled glazing and an innovative ducted energy recovery ventilation system linked to a solar wall. This wall is a black aluminium cladding that also performs the dual function of solar collector with the warm air drawn from the normal cladding cavity and fed into the ERV system.
An underfloor hydronic heating system has also been installed and LED lighting has been used throughout. During construction, the decision was made to add grey water recycling systems to both homes and it is this initiative that is taking them from the 9 star rating to 10.
The waste management plan for the project’s construction meant there was no skip bin provided on site, so workers had to be conscious of how to reuse or recycle as much as possible.
Mr Burnett said that in total the houses incorporated 20 sustainability initiatives that represented firsts for New Zealand.
He is part of an industry group that is aiming to encourage 1,000 new houses in Christchurch that rate 7 Homestar or more, in a bid to create a more sustainable rebuild.
“The rebuild is an unprecedented opportunity to make the city’s housing stock warmer, healthier and more energy efficient. A little extra thought and good design at the outset will lead to a lifetime of savings and good health,” Mr Burnett said.
One of the barriers to betterment, he said, was that the insurance companies had been road-blocking any improvements, including simple initiatives like adding insulation into walls.
“Betterment [has been] a dirty word for insurance companies,” he said.
Ms Cutler said it was pleasing to see an inspirational example of sustainable architecture in Christchurch.
“As the city rebuilds, a project like Church Square shows that embracing sustainability is not only smart but desirable. This home is stylish, energy efficient and built to high standards of earthquake resistance – it’s a fantastic milestone for sustainable home building in New Zealand,” she said.
For editorial suggestions please contact us at:
Phone the office on: +61 2 808 42291