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The Natural Life Cycle

In December 2015, the Paris Agreement brought hope to the global community setting a goal to be a net zero carbon society and pursue efforts to limit the global temperature increase to 1.5 0C.

I learnt that the real problems are natural problems; all other problems are problems that we have created. When we think of the real natural problems, Global Warming is the most well known. Looking at our social system and where the impacts that cause global warming are coming from, we quickly think of consumerism, transportation, food, our cities and infrastructure, waste and a few others. Now imagine a net zero carbon society, where we work through every aspect of our social and economic systems and quantify how we are performing on an annual basis. It’s complex, but there are many good stories happening within the construction industry, and it is getting more traction every year.

How is my building contributing to the situation?

When discussing building environmental performance with designers and builders we all want a best performing building, but the carbon performance target is not very often part of the project brief. It’s common to hear people talk about the “big picture” and reference the financial aspect as the most important but in reality there is no economy without ecology. Energy efficiency, durable materials, solar passive design to name a few, are all important design considerations and will improve building performance. But again, how good for the planet are the buildings we are designing? We can only reduce impact when we quantify potential issues throughout the whole building lifespan.

What performance are we measuring?

Before we can answer that question we have to remember what problem we are trying to solve and what our target is. To put it simply, the problem is Global Warming; a gradual increase in the overall temperature of the Earth’s atmosphere attributed to greenhouse effect, caused by increased level of carbon dioxide and other pollutants. The target we’re aiming for is a net zero carbon society, where all annual emissions are naturally absorbed by the planet without causing any harm to its natural cycle. The specific environmental impact indicator is Global Warming Potential (GWP), and it’s measured in mass of carbon equivalent (kgCO2e).

How to truly quantify environmental performance of buildings?

The only way to quantify the true environmental impact is by looking at the whole of building life cycle performance. Life Cycle Design utilises Life Cycle Assessment (LCA) to model whole of building performance, from construction through to end of life, all include use phase impacts. It also analyses functionality, and how well the project is delivering the proposed primary function. When designing a house for example, we want a dwelling that is comfortable, secure, healthy and in balance with the planet. By maximising the lifespan of a house, or the number of people it will provide shelter for, we can significantly improve the performance on a function unit basis (impact/occupant/year).

Our buildings are living organisms, and by understanding their impact on the environment and how we can design in balance with the natural life cycle, we will be able to make a more realistic plan towards the net zero carbon society we want to be part of.

Henrique Mendonça
Business Development Manager, eTool Global.

Measuring Sustainability in Residential Buildings

We get a lot of people asking us for a basic overview of what tools are available to measure sustainability performance and outcomes in buildings. Here is an overview of the main ‘Green Tools of the Trade’ for Green residential buildings in Australia.

Thankfully, measuring sustainability is becoming easier. There are now a number of ‘tools’ available on the market that will help you measure the sustainability credentials of your residential building project. The most common ones for Australia include NatHERS (6-Star BCA Code), Life Cycle Assessment (LCA) and Green Building Council of Australia’s (GBCA) ‘Green Star’ rating. Additional methods are available to test for heat/gain loss of a building. Models such as the One Planet Living Model and the Living Building Challenge really raise the bar for sustainable development.

NatHERS (6-Star)

The Nationwide House Energy Rating Scheme (NatHERS) applies to the residential sector; it is a national framework that regulates how Australian homes are rated for their thermal performance. NatHERS tools provide a method of demonstrating compliance with the minimum energy efficiency standards for new residential buildings outlined under the National Construction Code (NCC). The focus is on good design and construction which can reduce the operational costs and environment impacts associated with heating and cooling of a home. A minimum 6-Star performance standard became effective in West Australia on 1st May 2011; it is a minimum regulation which is intended to eliminate worst practice. The software is also a powerful tool for optimising energy efficient house designs for Australian climates. NatHERS accredited software includes Accurate Sustainability, BERS Professional, and FirstRate.

Life Cycle Assessment (LCA)

Life Cycle Assessment (LCA) is used to quantify the total “Embodied Energy” and the “Operational Energy” over the entire design life of the building. LCA looks beyond just thermal performance loads – the heating and cooling requirements of a home – and takes into account the impact of a building during its whole life cycle instead. Life Cycle Assessment evolved from the 1960s and is now defined with an International Standard, meaning that there are strict rules about how it is to be applied and relied upon. The standard is available at: AS/NZA ISO 14044:2006.

To achieve the best outcomes, it is recommended to engage a Life Cycle engineer early in the design process and help accurately quantify, compare, improve and certify the environmental performance of your building. It is an affordable and scientifically rigorous way to improve buidings and other forms of infrastructure. Perth based eTool®LCD is one of the few companies operating in this space.

GBCA Green Star

Green Star is a voluntary sustainability rating system for buildings in Australia. It was launched in 2003 by the Green Building Council of Australia (GBCA). The rating tool can be used for buildings, fit outs and community design; due to its costs this tool is mostly used by the commercial sector. Green Star independently assesses project by awarding points in nine categories: Management; Indoor Environment Quality; Energy; Transport; Water; Materials; Land Use & Ecology; Emissions and Innovation. Green star ratings are from 1 to 6 Green Star, with 6 being World Leadership. Performance ratings have to be re-certified every three years to make sure the building’s operations are up to date and to encourage improvement over time. The Green Star rating has helped lift the bar of sustainability outcomes in the built form.

NOTE: Additional ways to measure heat loss/gain

According to Your Home, ‘sealing your home against air leakage is one of the simplest upgrades you can undertake to increase your comfort while reducing your energy bills and carbon emissions by up to 25%’. Both insulation and air tightness are often difficult to inspect with the eye when a building is completed. Additional tests that can be conducted include a blower door test and thermal imaging; both help identify hotspots for heat loss/gain. A blower door test assesses the air tightness of the building; thermal imaging is used to inspect insulation of a building. In Europe, air leakage tests are mandatory in a number of jurisdictions including Sweden and the UK.

International Models for Best Practice

One Planet Living Model

The One Planet Living model is inspired by the UK’s first large-scale mixed use sustainable community: BedZED in London. One Planet Living is a vision for a world where it is easy, attractive, and affordable for people to lead happy and healthy lives with a fair share of the earth’s resources. It uses 10 principles as a holistic framework that provides guidance for local government, businesses and the built environment to comprehensively address key sustainability issues and effectively make a sustainable lifestyle a reality. The 10 principles include: zero carbon, zero waste, sustainable transport, sustainable materials sustainable food, sustainable water, land use and wild life, culture and community, equity and local economy, and health and happiness.

The Ultimate: Living Building Challenge

Currently there are only five ‘living buildings’ in the world. The Living Building Challenge is by far the most advanced and demanding measure of sustainability in the built environment possible today. It is a building certification program, advocacy tool and philosophy. It is comprised on seven performance categories called ‘petals’: Place, Water, Energy, Health & Happiness, Materials, Equity and Beauty. Examples of prerequisites include generating all energy with renewable resources; capturing and treating all water used in the building; and using building materials void of hazardous chemicals. Certification during the design stage is not an option; buildings need to prove that they meet all of the program requirements after 12 months of continued operations and full occupancy.

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