National Value Case for Sustainable Housing Innovations

The National Value Case for Sustainable Housing Innovations focuses on how an improved housing stock can be valued across a range of Government priorities, demonstrating the national and economy-wide benefits of having housing stock at a higher standard of sustainability than currently.

Using six energy and water saving innovations as examples, it builds a  compelling case for the kinds of interventions needed to achieve the Government’s vision of being a sustainable , carbon neutral nation.  Given the national benefits that would accrue from an improved housing stock, there is a strong argument to be made for incentivising uptake.

There is a strong case for both implementation of water efficiency technologies at a national level and for universal metering of domestic water supply.   Likewise, a value case exists for a much higher standard of insulation, space and water heating retrofit, than was currently undertaken as part of energy retrofit programmes.  The National Value Case also identifies opportunities and value from combining interventions and considering whole of house sustainability.


Combining the five innovations that were rated as Medium Weak or better, and spreading installation costs over 20 years, would generate a direct private economic gain to households equivalent to one percent of GDP by 2017 or about $2 billion.  Non-monetary benefits of healthier and more comfortable homes, and environmental benefits, are additional. 

Direct savings in household energy consumption amount to almost 22 PJ per year, or enough to power over 500,000 New Zealand homes for a year.  Most of the energy savings are in electricity use, implying a reduction in CO2 emissions of 3600kt per year, the equivalent of $54 million in tradable emissions (at $15/tonne).  Even allowing for take-back effects in the form of warmer and healthier homes and spending of household savings from energy on travel and other commodities, net economy-wide CO2 savings of 1600kt are still produced. 

Direct water savings amount to 81 litres per person per day, or about 130 million m3 per year.

What else is in our knowledge base?
  • Sustainable homes national value case report
  • Large scale renovation creates jobs
  • Waitakere NOW Home case study
  • Demand management through water retrofit projects
  • Sustainability options for retrofitting New Zealand houses: Energy
  • Sustainability retrofit options: Theoretical cost benefit analysis
  • Papakowhai Renovations case study