An article by Joanne Galea
A Holistic Approach to Building Sustainability
Many could be under the belief that it is the energy and water-efficient fixtures and low VOC (Volatile Organic Compound) finishes that satisfy sustainable and healthy building outcomes.
Important as these are, a holistic, whole of building fabric and systems approach is the attitude of this biological building designer.
Couple this with the sustainable and healthy nature of the furnishings, cleaning products, maintenance methods and personal products used in the building and the behaviour of building users than the bigger picture reflects the sustainable or otherwise impacts on the natural environment.
This article will focus on some of the key aspects in which structural elements can contribute to sustainable and healthy buildings for occupants. Typically, the modern trend to the sustainability of building material is to evaluate it against Life Cycle Analysis, carbon emissions and embodied energy. Each of these will be defined briefly followed by Building Biology qualities and suitable structural material selection examples.
Life Cycle Analysis
Life Cycle Analysis (LCA) is a method to assess the entire environmental impact of a building material or building product during the complete life cycle of the material or component. This includes evaluating the environmental impacts of all inputs and outputs (Australian Government Department of Climate Change and Energy Efficiency, p.v., 2012).
This begins from the raw material resource impacts through the manufacturing, transportation, use and end of use through to possible reuse, recycling (cradle to cradle) or to landfill (cradle to grave) (Braungart and McDonough, p.93, 2009).
Carbon Emissions
There are two terms linked to Carbon emissions, these are Greenhouse Gas Emissions (GHGE) and Carbon Neutral.
GHGE are atmospheric gases targeted as airborne pollutants considered responsible for global warming. These include Carbon dioxide(CO2), Methane(CH4), Nitrous Oxide(N2O), Hydro-fluorocarbons (HFCs), perfluorocarbons (PFCs) and Sulphur hexafluoride (SF6) (Australian Government Department for Climate Change and Energy Efficiency website, p. iv., 2012).
Carbon neutral is when the amount of Carbon dioxide emitted during the complete manufacture of a product is offset by other factors such as renewable power use with no Carbon dioxide emissions and Carbon sequestration properties of the product (Australian Government Department of the Environment website, n.d.).
Embedded into LCA is the calculation of Embodied Energy. This is the sum of energy in megajoules (MJ) used in the first stage of the life cycle up to the time that the product is ready for use (factory to the gate). Modern-day construction is responsible for 10% to 38% of the whole of life cycle embodied energy (Thiel et al, p.1127, 2013).
Durability in Design
The objective of durability in design – although not specifically a sustainable objective – is to ensure safety, health and amenity for the building users during the full building lifespan and providing longevity of building function. The National Construction Code (NCC) requires that buildings provide this safety, health and amenity for a minimum of 50 years and structural members are generally elements that are not accessible and not replaceable, hence requiring a minimum of 50 years of reliable use.
Evaluation of Building Materials
With this in mind, adopting the 25 Principles of Building Biology, Building Biologists evaluate building materials and systems using the following qualities with a double rating for those in bold:
- Natural occurrence
- Ecological compatibility
- Energy consumption
- Thermal properties
- Acoustic properties
- Diffusion/breathing properties
- Hygroscopicity
- Toxic vapours and gasses
- Electrical properties & radioactivity
- Health impact
- Overall impression
Selection of Healthy Building Materials
From this holistic analysis, I am trained to research and compare building materials to choose the most appropriate material to service the need.
An example is a preference for structural timber over steel members in areas where occupants spend significant periods of time, particularly in sleeping areas.
Electrical Properties and Radioactivity qualities of steel increase in electromagnetic radiation exposures that are detrimental to occupant health. Each steel member behaves as an antenna, capturing ambient radio, television and cell phone microwave radiation, reradiating these into the adjacent areas.
Another example is the choice of specifying an Eco ply structural ply bracing to reduce potential formaldehyde carcinogens in the building fabric.
Ultra-fine particulates and VOCs diffuse through building materials and can contaminate indoor air. Using fly ash in concrete is also something I would avoid to prevent worker’s exposure to 40% content of PM10 respirable particulates (Flyash Australia, p.1, 2010) and radioactive heavy metal toxins from coal waste residues (Meij & te Winkel, p.6, 2001) from being underfoot inside a building.
These are examples of selecting sustainable and healthy structural elements, each having its suitable placement by design.
Comprehensive Research of Building Materials
This short article gives just a taste of the comprehensive research in building materials to determine appropriate sustainability and healthy building structures. Touching base on LCA, carbon emissions, embodied energy and durability demonstrates where the Principles of Building Biology capture a greater sustainable and health outcome than is the current trend in sustainability alone.
References:
Australian Government Department of Climate Change and Energy Efficiency, 2012, National Carbon Offset Standard, Version 2, (Online), Available:
http://www.climatechange.gov.au/climate-change/carbon-neutral/national-carbon-offset-standard-ncos/national-carbon-offset-standard , (11 November, 2013).
Australian Government Department of the Environment website, n.d., Going Carbon Neutral, (Online), Available:
http://www.climatechange.gov.au/climate-change/going-carbon-neutral , (11 November, 2013).
Braungart, M & McDonough, W., 2009, Cradle to Cradle. Remaking the Way We Make things, Random House, UK.
Flyash Australia, 2010, Material Safety Data Sheet: Bayswater Flyash, (Online), Available:
http://www.flyashaustralia.com.au/_respub/_site/_img/content/Bayswater%20Fly%20Ash%20MSDS%20Jul2510.pdf , (3 February, 2015).
Meij, R. & te Winkel, H, 2001, Health aspects of coal fly ash, (Online), Available:
http://www.flyash.info/2001/keynote/21meij.pdf , (3 February, 2015).
Thiel, C.L., Campion, N., Landis, A.E., Jones, A.K., Schaefer, L.A. & Bilec, M.M., 2013, A Materials Life Cycle Assessment of a Net-Zero Energy Building, Energies 2013, 6, pp.1125-1141, (Online), Available:
http://www.mdpi.com/1996-1073/6/2/1125/pdf , (22 November 2013).
Joanne Galea is a designer and community stalwart.
2 replies on “A Holistic Approach to Building Sustainability”
It makes sense that you would want to have a self-sustaining home. The best way to go about that is to choose the right materials! I’ll be sure to have my home built with the best wood possible.
I think it’s really cool that sustainability has become more of an industry standard and something to strive for. My father always tells me about how quickly they put up buildings when he was young and how most of them are falling apart now. I think it’s great that 50 years of safety and health are required now so we aren’t wasting so much. Thanks for all of the information!