Build better buildings and start right now
New Zealand’s buildings are no good. For years we have neglected our building code and under invested in our existing stock. Now our homes are too cold and damp and the health service is spending billions of dollars each year treating New Zealanders suffering from building related health and wellbeing problems.
Now we are in the midst of a construction boom that in particular will build thousands of homes. These will lock in high energy requirements and poor health and wellbeing for decades to come.
On top of all that — from a climate perspective the building and construction sector is responsible for emissions equivalent to 12mT or 33% of New Zealand’s annual gross carbon emissions. For a quick recap — emissions in buildings generally come from two sources:
- Initially they come from the manufacture of materials used in the construction process — these embodied emissions generally makes up about 20% of total emissions of a building, but they are all released as the building is being built. On an annual basis these are about half of the emissions associated with buildings.
- Following that they come from the generation and supply energy and water to the house. These operational emissions generally makes up about 80% of the emissions, but they occur at a rate of about 1% per year. On an annual basis these are the other half.
Urgent action is needed now if New Zealand is realistically going to meet its goals to decarbonise by 2030 and beyond. This action needs to include a comprehensive overhaul of the building code and significant improvements to all the buildings that already exist.
From a carbon perspective it is possible to get 80% of the way there today — using technologies, materials and systems already in the market and scalable. These buildings will also be cheaper to run and New Zealanders will be healthier as a result.
This won’t be easy and will require an overhaul of current industry practices. Fortunately New Zealand has the biggest centrally coordinated construction programme for generations up its sleeve which it can use as a game changer to break through the inertia.
Fix the building code and fix it now
We need to begin with immediate significant and holistic changes to the building code and a change to the way our building code is managed.
The building code is broken down into a series of clauses (H1 for example), each of which sets requirements for each part of system of things that make up a building. This is managed by the Ministry for Business, Innovation & Employment (MBIE). Every so often MBIE goes through an update process for each of the clauses, like they are currently doing for H1.
The one clause at a time approach makes it extremely difficult to improve the performance of buildings. MBIE recognises this and will openly say that you can’t change one bit without changing others. However, that is where it ends. We end up paralysed by the amount of change that needs to happen and end up with tweaks that achieve very little.
Ultimately the rules that dictate the way we build are not managed in a way that will allow New Zealand to respond to the climate crisis appropriately.
In our view the whole building code needs to immediately be overhauled so that every clause is optimised to allow achievement of the following:
- Apartments and commercial buildings need to find a way to cut ~75% of the emissions out of their structures and foundations. This could be done by building out of timber, or would place significant pressure on concrete and steel industries to decarbonise. Within 4 years
- All concrete uses need to include low-carbon cement replacements. Within 2 years
- Energy performance ratings (in kwh/m2/a) are introduced for all new buildings and thermal energy caps put in place at close to 8 HomeStar or Passive House standards. This will reduce energy emissions by ~80% for new buildings. Within 4 years
- A ban on high emission factor refrigerants (R410A, R32 & R22 in particular) is introduced and a market created at scale for CO2 heatpumps. Within 2 years
- New Zealand’s refrigerant collection and destruction scheme needs to be made mandatory for heat pumps in situ. This needs to include penalties for non-compliance to ensure the ~0.7–1.5T of CO2 equivalent emissions in each heatpump in NZ is not released to the atmosphere. Within 2 years
- Minimum life standards need to be put in place for high embodied emissions materials that require lifecycle maintenance (carpet, cladding, etc.). Within 2 years
MBIE’s Building for Climate Change Programme (BfCC) is seeking to address these issues, but the timeframe is too long. From our perspective timing is critical. Our modelling for Kāinga Ora homes indicates:
- That under the proposed BFCC updates, by 2030 new buildings are performing 40% better. But this results in a only 0.2% reduction in total sector emissions by 2030 and 7% to 2050.
- The alternative proposed above would result in a new buildings performing 75% better by 2030, a 22% reduction of total sector emissions by 2030 and 39% by 2050.
- This does not consider potential emissions reductions that would be achieved by upgrading our existing homes.
Existing buildings
Most of our existing buildings will still be in use by 2050. The majority of these buildings will require deep retrofit by 2050, others we will simply have to write off and replace as not good enough.
In the UK, significant investment in existing buildings was mandated through the Energy Company Obligation. The idea behind this was to force carbon intense parts of the economy to invest in energy efficiency measures. This then reduces electricity consumption for decades to come and makes it easier for the energy sector to meet decarbonisation targets.
We need to start planning this now:
- Energy performance ratings (in kWh/m2/a) need to be introduced for all existing buildings with 5 years to comply. The aim of retrofit activates will be to improve the measured energy perforce with as little additional embodied emissions as possible. Similar to new builds caps can be reduced over time with buildings that do not meet the cap not being allowed to be occupied.
- By 2030 a minimum performance standard should be set for all existing homes. The standard should be tightened overtime to ensure that the by 2050 healthy temperatures can be maintained in all homes at low cost. This will develop a new market in deep retrofits. Mandated energy performance certificates also have the added benefit of being invaluable for the calculation and tracking of energy hardship metrics.
Then once the current construction boom ends, the New Zealand Government needs have a mechanism to pivot all the new capacity in the sector into delivering these low emissions retrofits.
Leverage our biggest opportunity to transform the sector
The New Zealand Government is currently in control of the largest centrally coordinated construction programme in generations and for generations. This construction programme is to deliver housing for the most socially and economically vulnerable New Zealand’s. These are New Zealanders who have been let down by our society in every other way.
The focus of this programme should be to build houses that are consistent with our Governments climate targets and to do so at such a scale that it breaks through the interia of our construction system.
Doing this could be a transformative programme of work that puts in place all of the market structures required to deliver low carbon buildings fast and at scale. It will also result in all of those architects, engineers and trades upskilling in how to build the way of the future and alleviate much of the training that would otherwise be needed.
Kāinga Ora is also at the beginning of an extremely large programme of work to upgrade 50,000 old public houses. This programme needs to launch a new industry of its own — one that delivers low carbon retrofits on mass. This is no easy job and it is difficult to get the balance right between improving efficiency and adding new high emissions materials. The learnings that come out of the Kāinga Ora programme and all energy efficiency upgrade programmes are of critical importance.
The large-scale improvement of the housing stock described here will result ease the transition to a low emission economy and improve the health and wellbeing of the entire population. Decisions being made right now will determine how:
- ‘Low carbon’ our homes, communities and cities are for the decades to come
- Many new jobs are created
- Healthy New Zealanders are and
- Difficult it is for our electricity sector to meet its decarbonisation goals.
It is not easy to prioritise doing things properly when we are in a rush, but that’s exactly what we need to do right now.
Keep an eye out for the next parts of our series
Among other opportunities we see that the critical moves to get this right being:
- Solving the built environment — what are the issues and the opportunities (part 1)
- We need to think differently about solving housing affordability (part 2)
- Design urban environments for the future not the past (part 4)
