New life for old buildings
Commercial building specialists are eyeing the Government’s $100 million ‘‘green’’ investment fund, launched in December, to help upcycle old buildings.
Engineering consultancy Beca said there was a huge opportunity to improve the country’s building stock, which is now believed to be belching out 20 per cent of New Zealand’s total carbon pollution.
Beca building services engineer Ben Masters said the 20 per cent estimate included the carbon emissions impact of extracting raw materials, manufacturing building components and demolishing and disposing of construction waste.
New builds generated a huge amount of carbon pollution, Masters said. ‘‘So rather than turning our cities into building sites, why aren’t we upcycling our existing building stock first?’’
The trend for developers to consider low-emissions options such as timber missed the bigger possibilities of reusing buildings.
The redevelopment of Aorangi House, a 1970s building in Wellington’s Molesworth St that was abandoned and leaking and saved from the wrecking ball, was a prime example of what could be achieved.
Beca won the World Green Building Council’s Leadership in Sustainable Design and Performance Award last year for the transformation of Aorangi House.
The refurbishment cost $9m versus $25m for a new build, with far less carbon emissions than demolishing and building new.
Natural ventilation, new solarcontrolled double glazing, external solar shading, and use of the building’s concrete mass to store heat in winter and cool the interior in summer were all features of how Beca and design partners Studio Pacific Architecture achieved a building that consumed 64 per cent less energy than a typical office building and performed better than most new commercial properties.
Masters said there were plenty of small ‘‘refurbs’’ but only a few fullblown upgrades like Aorangi House taking place.
The green fund, New Zealand Green Investment Finance Ltd (NZGIF), could help building owners grapple with energy refurbishments, Masters said.
The Government chose to announce the fund at Beca’s offices in Aorangi House. Energy efficiency in commercial buildings was one of the projects mentioned as suitable for fund investment along with electric vehicles, manufacturing processes and low-emissions farming practices.
Beca disagreed with an analysis that the fund’s goals were conflicting and that there was inherent risk in funding projects the market had failed to back.
Many landlords were strapped for cash, so if capital was available on attractive terms from NZGIF, that might persuade more landlords to tackle major energy refits, he said. ‘‘We see huge potential for it as long as it was structured in the right way.’’
Energy efficiency made more sense than investing in new technology that was not proven. Tuning a building’s energy systems using computers would pay for itself in less than two years and would have a big impact on the 1200 large office buildings in New Zealand that were responsible for over half of the emissions from office buildings, Masters said.
‘‘We’re saying energy efficiency is low risk because its proven to work.’’
Engineering building specialist David Fullbrook at eCubed said it was mostly the corporate property companies that were undertaking wholesale redevelopments of existing buildings.
Hundreds of commercial buildings were owned by smaller firms, which were focused on the rentals rather than on maintenance or retrofitting.
Tenants were attracted to shiny new buildings, Fullbrook said, so it might take a shift in thinking for redeveloped buildings to compete.
He said about 90 per cent of New Zealand’s building stock was existing and older buildings, while the remaining 10 per cent was new. So to reduce carbon emissions the older stock had to be upgraded for greater energy efficiency.
One of the issues was that lower energy bills following retrofits benefited tenants rather than landlords because of the way rental payments were structured. New buildings might have new energy systems but they were not managed well in New Zealand, Fullbrook said.
Many buildings could save 30 per cent of their energy consumption simply through better tuning and management systems, he said.
Green Building Council chief executive Andrew Eagles said the new green fund was welcome and ‘‘at least some form of support’’.
The single most important thing the Government could do was require a NABERSNZ energy-efficiency rating on the buildings it leased, Eagles said. The Government paid for the NABERS rating tool from Australia but it did not require the owners of buildings it leased to supply NABERS ratings.
‘‘Obviously you can throw money at things but perhaps the bigger step forward would be just for the Government to say: ‘When we are leasing we would expect a NABERS certificate on that building.’ ’’
Landlords would react to that and over time they would improve their energy systems, he said.