SUSTAINABLE MATERIALS

 

Legislation

 

The industry has submitted comments for the Building for the Climate Change Legislation (BfCC). If this goes ahead it will involve a shift in the industry, suppliers will have to adapt, designers will have to take more considerations and learn new tools at the design stage – so lots of changes. https://www.mbie.govt.nz/building-and-energy/building/building-for-climate-change/

 

 

Introduction

 

Typical materials offer functional and hopefully aesthetic value. All have negative impacts on nature and society through extracting ingredients, manufacture and distribution as well as repair and eventual disposal.

 

There are multiple facets of information and performance for materials and it’s often complicated to take all the different considerations into account especially Statutory Regulations, Industry Approvals and industry sales pitches.

 

Unfortunately, no single super material meets all our needs, and invariably we consider ‘groups of materials’ working as a ‘system’ with a required performance.

 

So, let’s not make it too hard and aim to make better materials decisions guided by some clear Purpose and Principles.

 

Instead of a world that is merely a less bad version of the one we currently have – ask a simple and profound question – What Does Good Look Like?

 

Creating a Healthy Home helps people and their family to live a more conscious healthier life, using less resources to do so and taking good care of our beautiful earth. Climate Change, Habitat loss, Biodiversity loss, toxic chemicals and significant wasted resources to landfill are key issues our building habits exacerbate, which we can address.

 

 

Principles

 

Principles for selecting Healthy Home materials may consider the following:

 

● Healthy for people and nature (no Red List toxic ingredients).

 

● Lower embodied carbon lifecycle (reduced climate effect).

 

● Are durable and easier to maintain in installation.

 

● Waste is avoided – we use what’s needed and reuse, recycle or compost at end of life.

 

● They work in combination as a ‘system’ to deliver optimal performance.

 

● Support local jobs and economies from sourcing and production.

 

● Use of materials that have robust technical support and ecolabels.

 

● Always ‘ask lots of questions’ of suppliers and learn!

 

Aside from minimising the harm, let’s also imagine the near future too, where the production of materials for Healthy Homes actually increases the health and resilience of our communities and local nature! We can help withstand the impacts of climate and economic change, pandemics like COVID-19 by using local suppliers, manufacturers and locally sourced ingredients.

 

For more information http://www.aucklanddesignmanual.co.nz/design-subjects/sustainability/shg#/design-subjects/sustainability/shg/guidance/approaches

 

 

Healthy for People and Nature – Ecolabels

 

Red List

 

Many materials, components, finishes, fixings, and complex assemblies contain ‘worst in class’ Red List synthetic, toxic chemicals. Exposure to people and nature is through manufacture, during construction or release during occupation and often during demolition too. These chemicals are carcinogenic, skin irritants, respiratory risks and hormone or immune system disrupting. They are long term trouble and it's best we avoid them for everyone’s wellbeing and health.

 

PVC (pipes, gutters, windows and vinyl) and CCA (Chrome Copper Arsenic) treated timber are very common examples in NZ. These are usually cheaper as they are mass produced and the ‘standard’ solution.

 

There is an argument for some materials being safer with lower levels or less harmful versions, but often little safety research has been completed and the Red List is the worst of the worst to avoid.

 

 

Lower Embodied Carbon Materials

 

Life Cycle Analysis LCA – is a methodology based on international standards for calculating all the environmental impacts of ingredients, materials or buildings. LCA considers the source of raw materials, manufacturing, distribution, assembly, maintenance and end of life disposal and is usually an industry average.

 

 

Global Green Tag https://www.globalgreentag.com

 

This is a third-party verified label offering disclosure of environmental and other impacts. This label is more affordable, accessible for specifiers and many products have this. There are various categories to ascribe differing environmental benefits.

 

 

Environmental Choice NZ https://environmentalchoice.org.nz

 

This is a third party verified Certification Label for products with reduced environmental impacts. This is an expensive system so products with ECNZ are typically more widely distributed consumer products.

 

Declare https://www.livingfuturenz.org/declare

 

The Declare materials label advocates for transparency in our industry by self-disclosure of product ingredients. Declare confirms where the product is made and what to do with it at end of life.

 

There is a searchable Declare global data base. In NZ the basic whole house envelope is available in products with Declare that are manufactured here.

 

 

 

Imports from EU Countries

 

Typically, products and systems that are imported from the European Union, comply with chemical standards, worker rights and waste obligations that are more stringent, with toxic chemicals are already banned. Many EU Eco-labels are trustworthy and represent high standards.

 

 

Environmental Product Declarations

 

EPDs are similar to LCAs but specific to a particular system or product brand.

 

Durability, Maintenance and Access

 

The NZ Climate and geography is particularly tough on buildings and materials – they ‘erode’ faster. This is a result of marine and coastal environments; with windy conditions, transporting salt and moisture deeper inland. It is also a result of our strong UV radiation which attacks just about all materials and finishes.

 

Building with eaves and overhangs, awnings to shade and protect surfaces along with regular maintenance such as annual washing is key to ensure durability and reducing wear and tear on the building fabric.

 

Designing for durability, maintenance and access, it is critical to ensure future planned maintenance and servicing is possible.

 

Materials as Systems

 

Optimise, don’t just maximise for performance. Hybrid structural solutions invariably require timer, steel and concrete.

 

Local

 

Where appropriate consider buying NZ made!

 

Sustainable Material Options

 

Hardfill

 

NZTA has determined that up to 15% reclaimed glass can be added to subbase aggregate in accordance with the relevant requirements of the M/4 aggregate specification.

 

Concrete

 

A recent development may provide for a better concrete product. https://www.stuff.co.nz/environment/climate-news/122567479/close-to-home-high-hopes-for-greenhouse-emissionsreducing-concrete

 

The Cement and Concrete Association (CCANZ), in partnership with BRANZ and supported by the Aggregate and Quarry Association of New Zealand, has published the Best Practice Guide for the Use of Recycled Aggregates and Materials in New Concrete.

 

Timber

 

Most timber products are considered sustainable and renewable. Engineered timber products like LVL, Glulam & CLT use more of the harvestable log.

 

Some products like CLT & OSB are actually imported into New Zealand and not made here as might be expected. It is worth doing some research on the glues being used to bind the timber in these materials.

 

One of the issues with using NZ grown Pinus Radiata is that is needs treating if in contact with the ground or exposed to the elements. These chemicals make a sustainable product, much less so.

 

Naturally durable timbers such as plantation grown cypresses, eucalyptus and Douglas fir may be considered as chemical free options. Timbers should be selected with at least the minimum durability rating suited to the end use application. http://www.nzwood.co.nz

 

Another option is heat treatment of locally grown timber to change its properties. Abodo’s Vulcan Cladding and Screening is made from FSC® certified radiata pine clear wood modified in New Zealand with a custom Thermowood schedule at 230 degrees. For further information https://www.abodo.co.nz/

 

Note that most Cedar cladding is imported into New Zealand from North America.

 

Windows

 

uPVC Aluminium and Wood - Life cycle assessment (LCA)

 

A Life Cycle Assessment of PVC and of Principal Competing Materials23 study commissioned in 2004 by the European Commission provides a highly valuable insight to environmental impacts of PVC, aluminium and wood through the production, use and disposal phases in the EU. The overall goal of the study was to compile an overview of the publicly available information on Life Cycle Assessments (LCA) on PVC and competing materials.

 

Findings include:

 

● The very high use of energy for the electrolysis of aluminium makes it a very environmentally unfriendly option contributing to global warming emissions. Additionally, aluminium’s eutrophication and acidification emissions are worst in class compared to PVC and wood window frame options.

 

● The coating of wooden window frame surfaces causes significant eco-toxicity emissions. Even water based paint systems do not manage to substitute solvents entirely, and not all paint systems give enough protection for window applications. Regular re-applications of surface treatment during the use phase are required for it to maintain its technical and thermal properties.

 

● Conversely PVC window frames contribute considerably less to environmental problems and require no coating or environmentally unfriendly maintenance but contain toxic Red List chemicals. See Appendices A and B for tabulated comparisons.

 

 

23http://www.pvc.org/upload/documents/PVC-final-report-lca.pdf