Will the new H1 requirements improve health outcomes and energy use?

No really - time to consider existing buildings.

Much has been made of the changes to H1/AS1. MBIE states that the changes will deliver warmer, drier and healthier homes that cost significantly less to heat and will also generate carbon savings through this energy efficiency. 

If only it were that easy.

Most buildings we live in and occupy are already in existence. The H1 changes are not existing building friendly and typically do not even apply. That alone reduces the likely claimed benefits.

For new buildings constructed to meet H1/AS1, overheating in summer could be a real risk. Have the air-conditioning costs been applied to the cost-benefit analysis? I doubt it.

Building code clause H1 is not about health outcomes.  It is about energy efficiency.  Building types such as assembly service buildings, industrial buildings, outbuildings or ancillary buildings are not required to be energy efficient.  So H1 is only really about the energy efficiency of new homes.  Last year 48,000 new homes were consented. That is about 3%† of the total number of homes in NZ.

I am not trying to rain on anyone’s parade. But if we really want to see improved health outcomes and increased energy efficiency, then we need to focus on the largest group of buildings – existing buildings.

And for the record, I absolutely believe we need to improve the quality of existing buildings.

There is no doubt that significant building performance improvements can be achieved by improving the thermal resistance of buildings.  But the system works against existing buildings.

Retrofitting ceilings and under floors is simple. Government cherry-picked this improvement and achieved a quick win by introducing a subsidised scheme.  Installation could be carried out without building consent and the associated costs and hassles.

Sadly, it left the walls, the difficult and more important aspect, out in the cold.

Costs were perceived as a barrier. In 2010, BRANZ carried out a cost-benefit analysis. They concluded that even with a payback period of 15 years, retrofitting insulation to weatherboard houses was not cost-effective. Hardly surprising, as the BRANZ preferred methodology involved the removal of all internal linings with the work requiring building consent and all associated costs and hassles.

However, that changed in 2014 and now homeowners have the option of a wall retrofit insulation solution that is cost-effective and works. I like to think achieving this was a quiet revolution, the result of a team effort.

At the helm was an entrepreneur who believed he had a good option. MBIE was also a key part. They agreed that NZ needed an effective, affordable retrofit solution and were prepared to use the Determination tool as intended. The customers were also important, as they were prepared to be part of the ‘journey’. Finally, Kevin Brunton and yours truly completed the team.

Insulmax is the product I am referring to and the entrepreneur, Phil Jackson. And let us not forget Phil’s energiser-sidekick Eamon Kilgariff.  

Enter Phil.  

Pottering in his garage, with only his crazy emu for company, Phil developed a product and installation methodology that addressed the issues associated with earlier blown-in foams. He removed the moisture and formaldehyde, and delivered a product that came with a better R-value. 

He then asked Kevin Brunton and me (as directors of The Building Business) to help him to “get it through council”. 

We believed that we could mitigate the risk of a leaky building by applying a risk-managed approach based on the risk matrix principles in E2/AS1.

A risk and reward trade-off.

Unsurprisingly, BRANZ and the councils created significant barriers, only to be expected where risk avoidance is the mantra. 

However, this is where the Determination was so important and effective. A Determination is a tool for clarifying code compliance as well as for critiquing a council’s decision. The process allows for MBIE to draw on a mix of technical and expert advice.

I can’t say we always agreed with the decisions reached by John Gardiner, the Determinations Manager at the time, but we were all on the same page. 

We were looking for a solution that meant warmer, healthier homes at a cost-effective price and without unintended consequences.

The team of experts combined with the resolution approach taken by John meant that all possible issues were worked through logically and carefully until a solution was reached.

The proof is in the pudding. Were we successful? Well the approach developed and tested through the Determination process is still being used by Insulmax and has been adopted by others. The process and product has also been certified through CodeMark.

So what is the point of this blog? 

Achieving population-based improvements through improved building performance relies on maximising the number of buildings that incorporate the change.

A change may not be a 5-star, gold plated option, but it delivers results through sheer volume.

Changes can happen by applying robust building science principles, the correct application of the regulatory framework and the willingness of all sectors to work professionally for a common public-good goal. 

To those who advocate that nothing less than H1/AS1 (amend 5) will do and that non-compliance is bordering on negligence; take care.  The changes will deliver health and energy efficiency improvements. But realistically, this is only for a relatively small number of building owners. It is time to think about existing buildings - what can be achieved, and how can we use the system to make is simple, cost effective and without unintended consequences.

Phil tells me that business is good, and he still has his emus.

Rug up warmly until next time.

Louise Swann
The Good Building Consultant

† Figure updated 09 June 2022.