Roofing Leading the Way

Environment Transformation Lead for the sector, Jennifer Taylor argues the case for a ‘circular economy’ in construction in order to reduce our collective impact on the environment.

The common saying, ‘as long as I have a roof over my head,’ shows just how highly valued a roof is. No mention of walls or floors in this old adage, but a roof is recognised as a key part of our basic human needs – it provides us with shelter. In the same way that a hat can shield us from the effects of the summer sun, protect us from wind, or keep us warm in winter, a roof is a critical part of a building. So how can we provide this need for shelter amongst climate change?

Merely weeks into 2023, Aotearoa New Zealand, has experienced severe flooding in the upper North Island, increased rainfall in the east, unexpected high temperatures down south, and even a tropical cyclone and a tornado. With climate change, we will no doubt see more unprecedented and unpredictable weather affecting greater numbers of people and structures throughout our country and with increasing frequency.

A circular economy

You may or may not have heard of the concept of a circular economy, but this is one way to consider our environmental impact and, therefore, our contribution to climate change as a sector. A circular economy reduces material use, re-designs materials, products, and services to be less resource intensive, and re-captures ‘waste’ as a resource to manufacture new materials and products (US Environmental Protection Agency). For us, as businesses, it can be helpful to think of a circular economy as aligning with what we consider is a good business practice: the idea of doing the job right the first time, with the right materials, efficiently, with less waste – and recognising resources have value at the end of their life and need to be reused/recycled where possible.

Roofing is leading the way

In this end-of-life phase, roofing is a superstar among our trades. Roofers have already recognised that rather than being ‘waste’, our old iron roofs and/or steel offcuts represent money left on the table. Did you know that around 85% of all steel from construction in New Zealand is currently being recycled? Collectively, as a trade, roofing has already applied circular thinking. Some of these resources could have been viewed as throw-away items, but instead, they have become of value.

Do you think climate change and its effects are outside your influence as a roofing professional? Well, they certainly are not. I can assure you that your continued help is needed to make a difference. As a starter, continue your efforts in recycling your metal and other materials – and keep a lookout for that remaining 15%!

Change is achievable for everyone

For each roof you visit and potentially quote, consider what your expertise tells you to offer rather than taking the specified item as definitive. Again, the best practice for your business will often be the best practice for a circular economy and climate change. No one knows roofs like you do. So, add your value to the conversation and educate your customers about what could be most suitable in their situation.

Here are some ideas and tips to consider:

• The durability of the products

What is the best product for the job? A more durable solution will require less product replacement over its lifetime, but also save resource (and carbon too).


• Preparing for the changes in the intensity of rainfall

Are there internal gutters in the design? Does the client understand the maintenance involved in clearing these? In heavy rain, could they overflow into the building? Could the design be altered to remove these, or at least position them over non-living areas? Should the gutters and downpipes be upsized?

Increasing dry periods and emergency water supply

Over time, water will become more recognised as a valuable and scarce resource. Also, metering/charging will become more prevalent across New Zealand (and already is in many places). Consider whether a run-off system could be installed. Has the client thought about storage tanks, not only handy for the garden in dry periods but also as an emergency drinking supply in case of emergency? Ironically, the need for clean drinking water is often during times of too much rainfall, which means town-supply can become contaminated. To learn more about water storage from roof run-off, check out this Build Magazine article:


Eaves are more than a style statement. They also help to reduce direct solar gain during the hottest months. Current trends show us that overheating in summer (particularly in new, highly insulated houses) will be a major issue in the future.

Reduce heat gain

In hot, heat-wave-prone areas, make your clients aware of the potential impacts of dark colours on the overall surrounding temperature – particularly in hotter summers. Dark roofs are implicated in creating the urban heat island effect (hotter urban areas due to surfaces that absorb heat). In this situation, you could recommend cooler paint colours/types or a more insulated roof material.

Energy production

If you work in sunny locations with north-facing faces on a roof, ask whether solar panels have been considered. With the cost of electricity forever increasing and the cost of PV (photovoltaic) technology decreasing, the economics is improving daily. Product design is also changing. For example, it is now possible to have roof profiles with wider ribs that fit solar panels.


Go wild

Commercial buildings in high-density areas will likely see more ‘green roofs’ – living, planted spaces. With increased demand by commercial operators for Greenstar buildings and the desire for more sustainable buildings, the gold standard is a green roof. It is more expensive than a traditional option, in particular, due to the increased weight load. However, the benefits include reducing stormwater run-off by up to 65%, cooling the roof surface by 30-40% (a double bonus with reducing both energy use for cooling and the urban heat island effect), attracting wildlife, removing carbon dioxide to create oxygen, reduction of noise, an extension of the roof’s lifespan, and making the roof a useable, pleasant space. A green roof may sound a little futuristic at this point, but due to the multitude of climate change benefits, it’s certainly worth keeping in mind.


In the case of a re-roof, does it actually need replacing? Could some well-placed repairs give the roof another five years and extend the life of that resource? It may seem counter-intuitive for your own business, but the honesty of providing an alternative view could see you performing the repairs and the re-roof in years to come.


I’m sure you can think of many more situations where you can use your knowledge and expertise to inform your clients about improved roofing solutions – to provide benefits for them and reduce the future impacts of climate change. Keep up the great work, and remember – our actions will help our buildings be more resilient to the impacts of climate change and assist in seeing our sector progress.

Please let me know your ideas about how to continue roofing Aotearoa New Zealand better, applying circular economy principles. I look forward to hearing from you.

- Jennifer Taylor

Environment Transformation Lead, Construction Sector Accord

Contact Jennifer on LinkedIn at the link here


This article was written for and published in our RoofLink magazine, the RANZ membership journal and roofing industry quarterly publication. For more information on becoming a RANZ Member see the link here