An Assessment of the Need to Adapt Buildings in NZ to the Impacts of Climate Change





The scientific evidence is very strong: climate change presents very serious global risks, and it demands an urgent global response. The objective of this report is to assess the need to adapt houses in New Zealand to climate change. Our assessment is based on medium-low and medium-high climate change scenarios from research by NIWA. To explore the building sector’s vulnerability to climate change:

  • The topology and condition of the national building stocks was reviewed;
  • Regional and district councils were surveyed to collect climate related damages;
  • Overheating conditions and energy consumption scenarios were simulated; and
  • Scenario-based methodology was used to investigate social impacts.

Adaptation options and recommendations are generated for a broad range of building related climate change impacts. Economic modelling and cost benefit analyses are used to investigate the economic viability of a range of adaptation options. The Climate Change Sustainability Index is revisited as a tool to assess building climate change vulnerability.

Although the effects of climate change are expected to be less severe in New Zealand than in many other parts of the world, the key message from this report is that the strong-, early-, and coordinated action on climate change can limit potentially large social, cultural and economic costs in New Zealand.

There are twelve key recommendations emerging from An Assessment of the Need to Adapt Buildings in New Zealand to the Impacts of Climate Change:

R1: Implement a Climate Change Adaptation Plan for New Zealand: It is essential that the climate-change planning process start now, given the longevity of housing developments and infrastructure in increasingly at-risk communities. Local councils have an important role to play in reducing flood (inland and coastal) and fire vulnerability through development control and zoning. Direct regulatory and market interventions might be required to re-orient the sector and enable a consistent and proactive approach, but these can be expected to generate controversy and to apply in different ways across the country.

R2: Develop and Retrofit with Consideration of Increasing Climate Exposure and Vulnerability: Regions with high climate change exposure from increased risk of flood, bushfire, temperature extremes and coastal hazards should be avoided or developed with due consideration of future climate change impacts. This study has identified recommendations for adaptation to key climate change risk elements, with particular focus on adaptation to building overheating. As such, increased uptake of insulation in the existing housing is shown to have strong economic net benefits.

R3: Use recent natural events (e.g. storms/ flooding/ erosion/ landslips) to raise awareness of climate change impacts on housing and our way of life: Housing adaptations can profitably be oriented to raising concern over storms/ flooding/ erosion/ landslips as a threat to the New Zealand way of life, with particular impact for coastal communities/ houses. Loss of iconic housing locations, lifestyles and landscapes is a powerful motivator for public concern. Note that adaptations need to be accessible to the full range of households – from the highest to lowest income – to account for flow-on effects where housing/ property values are reconfigured. Any communications need to avoid adding to social conflict.

R4: Learn How to Communicate about Climate Change and Adaptation: Develop a communications strategy that makes it easy for the public to understand climate change, its impacts, and the need for housing adaptation specifically. The issue of climate change (and sustainability in general) require different ways of thinking about social problems, both among communicators and their target publics. These are not obvious, and will sometimes be counter-intuitive, so communicating about climate change needs to carefully researched and developed into strategies specific to the housing sector. Best case examples currently come from sustainability-oriented communications agencies and these may be important partners in developing communications within the housing sector.

R5: Develop Behavioural Change Programmes: Develop behaviour change programmes that make behaviour change easy, attractive, stylish, and rewarding. Systemic programmes may need to span areas such as design, building, renovating, financing, and insuring as well as ownership/ dwelling. Behaviour change is often understood in relation to the public or consumers, it is also critical to engage housing sector, industries and institutions in behaviour change. Again, research may be required to develop programmes appropriate to the housing sector.

R6: Build the Sector’s Proactivity: Develop a proactive approach that leverages research – such as this report – towards a coherent and effective sectoral response to climate change. This project is part of an initiative to manage the housing and social impacts of climate change proactively. To further this proactivity, some work should be directed towards mobilising a sectoral response. To that end tactical use of concerns such as flooding and social exclusion may help mobilise sector stakeholders to deal with climate change issues. Synergies may be may be achieved with initiatives that deal with health and other social issues.

R7: Orient Housing Adaptation to Social Exclusion: As the broader strategic platform it is recommended that adaptations are oriented to the more vulnerable and socially excluded groups. First, these groups can help establish minimal standards/ acceptable solutions for successful housing adaptations and outcomes. Second, they are relatively easily identified via measures of social inclusion/ exclusion (such as household income, ethnicity, and house condition) and so programmes to target these households/ houses are relatively simple to construct. Third, these groups may show the more significant social gains during normal weather patterns, as well as after more extreme events.

R8: Integrate Other Sectors in Future Work: Coordinate building adaptation to climate change with other societal, institutional and technical drivers for change. Design of housing adaptations for climate change cannot be separated from design for other changes. Housing needs and vulnerabilities are concurrently shifting due to an ageing population, increasing obesity and so on. This means the housing sector can best evolve successful adaptations by working closely with sectors such as health, education, justice and urban planning. As mentioned, other sectors are already engaged in housing-related initiatives, and in this sense may actually lead the housing sector at the present time. Positioning the sector for leadership in adaptation to climate change may be an issue in itself.

R9: Reduce Sector’s Carbon Footprint: Stimulate uptake of energy efficient techniques and practices and renewable energy generation. Policy instruments to reduce greenhouse gas emissions, such as increased costs from carbon or GHG charges pose a risk to tenants and the building industry. Energy efficiency and utilisation of renewable and low-carbon energy sources (e.g. solar, wind and biofuel) can help reduce exposure. As such, opportunities from global warming from less required water heating and winter space heating can be used to address energy price vulnerability). It is advisable to incorporate lifecycle embodied energy and lifecycle environmental impact into comparisons of building materials and construction design.

R10: Improve Confidence in Climate Science: Improve confidence in projections of key climate change implications for New Zealand. The results from the CSIRO and Hadley models employed in this study differ significantly in some areas. The need to adapt buildings to climate change needs to be re-evaluated as increased certainty is gained on the regional distribution-, direction- and magnitude of change for the elements ex-tropical cyclones, wind, storm, hail and rainfall.

R11: Continue Working with Scenarios for Social Impacts: A central, longer-term task is to develop a ‘strategic discussion’ about the role and activities of housing in managing the social impacts of climate change. The social scenarios developed for this study are an initial step, using the best information available from current published sources and the knowledge of experts in the study. A strategic discussion needs to be oriented to integrate and update the knowledge available from all stakeholders, to apply it to sectoral leadership, and so to initiatives within the sector. The scenario framework is a useful way of engaging other sectors in planning, in organising knowledge to anticipate changes in the sector, and in directing effective strategies and implementations.

R12: Develop the CCSI and include Bushfire and Drought Risk: It is recommended that the CCSI is expanded to include building vulnerability from increased fire and drought risk. The Climate Change Sustainability Index is a unique method to assess vulnerability of New Zealand houses and offices with regards to floods, ex-tropical cyclones, overheating and GHG emissions.















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