Sustainable Design Manual

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Sustainable Design Manual Many people dream of building or rennovating a sustainable home.

But one of the main requests we have from Green Pages readers is 'how do I do it? The principles of sustainable design are fairly straight forward and can be adopted by any builder or architect without adding substantial expense to a home build.

The art of sustainable design is built upon largely upon the relationship between site layout,

for an environmentally low impact home

solar access, energy efficiency, climatology and thermodynamics.

This manual shows a detailed explainations and diagrams on these simple principles and how they can make an enourmous impact upon comfort, occupant health and cost savings over time.

We have provided detailed information on toxic paints and how to avoid volatile organic compounds from infiltrating your home. Effective use of landscaping, pagolas and deciduous trees can assist passive heating and cooling of living areas and act as effective grey water treatment systems.

It's important to note that sustainble principles can be achieved with a modern and sylish architectural design and by no means necessitates an unusual looking home.

As new state and council regulation specify 5 star energy efficiency design and water efficiency, home owners need a greater understanding of these factors.

Of course, an energy and water efficient home, is an economical home, saving potentially thousands of dollars per year.

“Australia experiences harsh climate extremes. For this reason we need to protect not only ourselves in how we live but also the resources available such as water and even building materials.�

Australia experiences harsh climate extremes. For this reason we need to protect not only ourselves in how we live, but also the resources available such as water and building materials.

This manual shows how to choose materials for buildings or renovations that are low in toxicity, provide thermal efficiency and can be used again to reduce embodied

Greenhouse gas emissions from home energy use

consumption of the material.

Choosing building materials and interior furnishings for health and toxicity is also important to avoiding offgasing of indoor pollutants, mould and dust.

Water Heating 23% Cooking 5% Standby 5% Lighting 11% Refrigeration 12% Heating & Cooling 20% Other Appliances 24% (Baseline Energy Estimates, 2008)

Home energy use Heating & Cooling 38% Standby 3% Cooking 4% Lighting 7% Refrigeration 7% Other Appliances 16% Water Heating 25% (Baseline Energy Estimates, 2008)

“The percentage of greenhouse gas emissions from home energy use depends on the carbon intensity of the energy source. For example, the carbon intensity of electricity is much higher than that of natural gas or wood per unit of delivered energy. Therefore, although heating and cooling is the highest energy use in the home, as natural gas is typically used for heating, it is not the highest greenhouse gas emitter.”

Futhermore, the simple layout and furnishing of a room can be altered or designed to encourage ventilation, capture cool breezes, shade the sun and prevent heat loss in winter.

Although the topic of 'green building' has garned much interest in the last couple of years, the philosophy behind passive solar design is ancient in that it emodies how a building can provide habitat efficiently within a specific climate.

What is relatively new is the software and computer modelling programs available to assist in passive design and performance. Recently, downloadable tools have been designed to help the home designer work out the specifics of how site, solar access, house layout and materials choices can maximise energy performance of a home. The software may initially cost, but the design predictions may prevent costly mistakes. Energy rating software, First Rate is downloadable for $550 from the Sustainability Victoria website.

Information and diagrams for this manual have been sourced from ‘Your Home’ which is a Australian Government initiative managed by the Department of Environment, Water, Heritage and the Arts and is available online at www.youhome.gov.au

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How to rate your home’s environmental performance: Rating tools are important to provide a general benchmark for sustainable design. They can be very useful is assisting the home deigner to learn the specific requiresments such as window elevation, lenth of eves and positioning of thermal mass materials. Rating tools come in the form of computer software that not only can provide assessment for new buildings, but also can assist in possible changes to design for comfort and energy efficiency. Anyone can buy and use the software, but ratings used for assessing compliance with regulations can only be issued by trained and accredited assessors.

Just like products, there is a wide range of assessment tools and rating schemes that look at different aspects of a building’s environmental performance.

For example, the energy rating of a new single dwelling can be determined by the Protocol for House Energy Rating Software.

Check with your State or Territory Building Control Administrators for the suitable version. Further Information can be found at the Australian Building Codes Board www.abcb.gov.au

Product & Appliance Ratings Window Energy Rating Scheme www.wers.net

Energy Star Ratings www.energyrating.gov.au

Water Efficiency Standards www.waterrating.gov.au

Good Environmental Choice www.geca.org.au

First Rate 5

AccuRate

NatHERS & BERS

First rate has been developed by the Victorian Government to speed up the rating system.

It can be downloaded for $550 and is relatively straight forward to use. It is used by qualified energy rating professions and is the most popular tool used in Victoria.

AccuRate was developed by the CSIRO as an evolution upon the original NatHERS software. The software requires detailed architecural and building product information. It is available for $695.

The original NatHERS software has been replaced with AccuRate, although the scheme still exists. BERS is based on AccuRATE and is most widely used in Queensland. A BERS trial can be downloaded free of charge.

NABERS HOME

BASIX

Green Star

NABERS is an easy-to-use tool for comparing the energy and water use of an average household. It incorporates occupant behavoir and technical design, including 12 months of actual energy and water use, providing a compliment to the exisitng tools.

The NSW government introduced the BASIX, the Building Sustainability Index to provide a minimum benchmark for all new developments. It works on the methodology of minimum energy and water usage required to acheive a planning permit.

Green Star is a highly technical rating tool for commercial and multidwelling residential apartments. The ratings are completed by qualified engineers and require a range of specfic software, however the result is a comprehensive green rating.

www.sustainability.vic.gov.au

www.nabers.com.au

www.hearne.com.au/ products/accurate/

www.basix.nsw.gov.au

www.nathers.gov.au www.solarlogic.com.au

www.gbca.org.au

“Recent studies demonstrate that mandatory disclosure of energy efficiency in the ACT shows a very strong correlation between star ratings and house value – something in the region of 3 per cent for each star. So a $400,000 house increases value by $12,000 per star which makes energy efficiency a very good investment.”

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How to design for your climate: Design for climatic zones

Australia has a broad range of climate zones that are characterised from alpine to hot and humid. Only a very small area of Australia however experiences the cold extremes as seen in Northern Europe and America.

Hot extremes, however, are predominant in many Australian localities and therefore, climate should be a main design consideration.

Unfortunately, many homes are still built without consideration for such climatic differences, resulting in light weight weather boards in Hobart and brick

NSW, WA & SA: Mild Temperate

VIC & TAS Cool Temperate

Key Design Responses:

Key Design Responses:

Key Design Responses

•

•

•

• •

veneer homes in Queensland.

Climate conditions in Cairns would require design

•

responses like selecting a site exposed to cooling breezes, ventilated roof spaces, thick roof insulation, using light weight (low mass) construction material and also significant shading from vegetation.

On the other hand, houses in the Adelaide or Sydney region should be built with high insulation levels, adjustable shading and heavy thermal mass to protect against the powerful summer heat and retain consistency in Winter. A cool climate home should feature large amounts of brick, stone, concrete.

Orientation to the sun in critical in the cooler climate as the home should catch the winter sun to heats the house passively. Geographic and topoligical maps should be studied while considering the house design and position.

Despite the differences for climate, most passive solar design principles remain constant.

QLD: Warm humid

• • • •

Insulated thermal mass Minimise east west glazing Cross ventilation Site homes for access to cool breezes Reflective Insulation for summer heat Shading of north facing areas Vegetation for shading Heavy ceiling insulation

• • •

• • •

High use of thermal mass Maximise north facing glazing Adjustable shading Heavy draped and curtains to insulate windows Protection from cold wind Seal all drafts around doors and windows Heavy insulation in walls and ceiling

• • •

• •

High use of thermal mass Insulate thermal mass and slab edges Minimise external wall areas Insulate ceilings, walls and exposed floors.

Double glazed windows Heavy draped and curtains to insulate windows

Orientation for passive heating Winter midday shadow

Summer

W

Winter

S

N

Summer midday shadow

E

The angle of the sun during Summer and Winter varies considerably. Your home needs to be positioned to maximise the sunny north facing position whilst maintaining windows and eve specification to allow winter sun in and block out summer sun. You should first eastablish where true or solar north is in relation to your property.

Finding optimum ‘Solar access’

N North slope advantage

N

South slope disadvantage

Positioning on a slope

A north facing slope increases access to northern sun and is ideal for higher housing densities. A south facing slope increases the potential for overshadowing. North is the best direction to locate windows and living areas. If the view is to the south, avoid large areas of glass in order to minimise winter heat loss.

Cross flow breezes

This diagram shows how the layout of a house in a warm temperate climate allows winter sun in and lets summer breezes flow through. The windows and doors should be positined to allow a complete thoroughfare for breezes to provide a purge of all hot air in summer.

Providing solar access amongst obstructions, using a split ceiling window

On sites with poor orientation or limited solar access due to obstructions, an energy efficient home is still achievable through careful design such as a north facing split ceiling window. Use of advanced glazing systems and adjustable louvres can achieve net winter solar gains from windows facing almost any direction while limiting summer heat gain to a manageable level.

Living arrangement set up

The ideal orientation for living areas is within the range 15ºW-20ºE of true or ‘solar’ north. (20ºW- 30ºE of true north is considered acceptable). Furniture, thermal mass and heating elements should be positioned away from windows and doors to minimise heat loss for the main occupied areas and increase comfort levels.

Deflecting breezes for new and existing homes

Deflecting cold winds for cooler climates and in winter

Capturing cool breezes for warmer climates and in summer

If your site experiences strong cold winds from a particular direction, you can construct the design to minimise the total surface area and the windows area that faces the wind's direction. This will allow the wind to move around the main living areas, rather than directly toward them.

For warmer climates, a larger opening such as a double door can be provided with a well planned path for the breeze to travel though the home and out the other side. Positioning of trees and shrubs can assist to deflect or assist the breeze to move in and around the home.

Trees will always provide a buffer to strong winds.

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Shading to reduce summer temperatures Summer

Winter Sth-facing courtyard with fernery

deciduous trees & vines to Nth

Deciduous trees shade Keep evergreen trees east walls and windows away from house Use of decidious vegetation or operable shading to increase winter sun and decreaes summer heat

Calculating window eave height to allow winter sun access and prevent summer sun

Optimum positioning of trees and vines for climate contol

External shading should use operable light, fixed devices that reflect heat. Eaves, awnings and pergolas that are set to the correct angle will create shade. Decidious vines or trees are very useful to allow winter sun when the branches are bare, while the seasonal foliage will deflect the sun during summer.

Evergreen vines and plants are good for hot climates.

The ‘rule of thumb’ for calculating eaves width is 45% of the height of the window plus 30% of the window height in wall space. This rule applies to all latitudes south of and including 27.5.

For latitudes north of this the response varies with climate.

If orientation is east or west facing, it is recommended that glazing is kept to a minimum with adjustable shading.

Foliage is a quintessential attribute to shading and heat management. Choosing the type of canopy height, density and plant species and determining the position of the vegetation is essential to acheive your desired climatic control. Plants also assist in cooling via their natural transpiration process that releases moisture into the surrounding atmosphere.

Evaporative Cooling Cool air (cooling by evaporation)

Protection from hot dusty wind

Pool

Reduced heat admission

Cool Surface

Cleverly positioned water features can create cooling via convective breezes. Passive evaporative cooling design includes the use of pools, ponds or water features that are positioned outside windows or in courtyards. Large amounts of heat are absorbed by the water as it evaporates whereby it precools the air entering the house.

Goldfish can also be added to eat any mosquito larvae.

Envelope Design Tips •

Orientation for exposure to cooling breezes.

•

Increase natural ventilation by reducing barriers to air paths through the building.

•

Provision of fans to provide ventilation and air movement in the absence of breezes.

•

Provide paths for warm air to exit the building.

•

Floor plan zoning to maximise comfort for daytime activities and sleeping comfort.

•

Light coloured external surfaces to reflect light

•

Appropriate windows and glazing to minimise unwanted heat gains and maximise ventilation.

•

Effective shading (including planting).

•

Adequate levels of appropriate insulation.

•

High thermal mass construction in regions with significant diurnal ranges.

•

Low thermal mass construction in regions with low diurnal range.

•

Use of light coloured roofs and walls to reflect more solar radiation and reduce heat gain

•

Design ceilings and furnishing positions for optimum efficiency of fans, cool breezes and ventilation.

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How to minimise heat loss passively: It's very simple and cost effective to minimise heat loss in the home.

Typical heat losses in a temperate climate

The major factors to consider are window glazing, thermal mass, insulation, air infiltration, sealing doors and windows and the aspect.

Choose double glazed windows with additional seals. A standard 3mm glazing allows heat to pass through the glass and be absorbed into the air pocket inside. Heavy curtains with pelmets will insulate the glass against heat loss.

Select building materials with a high thermal mass (usually masonry) as this will absorb and store heat.

Ceiling and roof space accounts for 25 to 35 per cent of heat loss, so thick insulation in ceilings is a must. When choosing the type of insulation, plant cellulose fibre eliminates fewer toxins (and is a recycled product) than polyester, fibreglass, mineral wool or recycled paper and foam.

Rooms such as storage spaces, laundries or garages and need to be contained with a sealed door to keep out winter draughts.

“The major factors to consider in minimising heat loss are window glazing, thermal mass, insulation, air infiltration, and sealing doors and windows”

Heat Loss Tips •

Use airtight construction detailing, particularly at wall/ceiling and wall/floor junctions.

•

Control ventilation so it occurs when and where you want it.

•

Choose well made windows and doors with airtight seals.

•

Improve the performance of existing windows and doors by using draught-proofing strips. Use between the door and frame, at the door base and between the openable sash of the window and the frame.

•

Seal gaps between the window/door frame and the wall prior to fitting architraves.

•

Avoid using downlights that penetrate ceiling insulation.

•

Duct exhaust fans and install non-return baffles.

•

Avoid open fires and fit dampers to chimneys and flues.

•

Do not use permanently ventilated skylights.

•

Use tight fitting floor boards and insulate the underside of timber floors in cooler climates.

•

Seal off air vents, use windows and doors for ventilation as required. This may not be advisable for homes with unflued gas heaters that require a level of fixed ventilation.

Typical sources of air leakage vented skylight

gaps between walls and ceilings air vents

exhaust fans vented downlights

gaps between and around windows

fixed air conditioners and heaters gaps between doors

gaps up chimney

construction joints between wall materials

gaps between floor boards

gaps where pipes penetrate walls

gaps between walls floors and skirting boards

Thermal Mass Thermal mass materials have the properties of high density, good thermal conductivity and low reflectivity. Correct use of thermal mass can control the internal house climate as it averages-out day/night extremes. It is the thermal battery of the house. Thermal mass is not a substitute for insulation. Thermal mass absorbs and radiates heat whereas insulation stops heat flowing in and out of the building.

Thermal Mass Tips: • Best positioned within the building envelope, on the southern side.

• It needs to be left exposed, not covered by carpet.

• For heating, it needs to be positioned near heating elements in the centre of the home, for example a stone area surrounding the main heating unit.

• Positioned in the centre of the home, surrounded by an insulated building envelope.

• Water has the highest thermal properties of all materials, so use nearby of water tanks, gardens, plants and ponds will assist with temperature regulation.

• Avoid insulating in the interior of the thermal mass, such installing insulation behind a brick veneer.

Winter

Thermal mass absorbs winter sun and radiates heat by night Summer

Thermal mass cools down and absobs heat during summer evenings

MATERIAL

THERMAL MASS

(volumetric heat capacity, KJ/m³.k)

Water Concrete Sandstone Compressed earth blocks Rammed earth FC sheet (compressed) Brick Earth wall (adobe) AAC

4186 2060 1800 1740 1673 1530 1360 1300 550

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Insulation materials Under the Energy Efficient Homes Package, the Australian Government is offering up to $1,200 for ceiling insulation, a $1,600 rebate for installing a solar hot water system or a $1,000 rebate for installing a heat pump, to replace an electric hot water system.

A well insulated and well designed home will provide yearround comfort, cutting cooling and heating bills by up to 45 per cent. This, in turn, also reduces greenhouse gas emissions.

Climatic conditions will influence the appropriate level and type of insulation.

Insulation must cater for seasonal as well as daily variations in temperature as well as assisting as a sound insulator if required.

The type and thickness of the insulation will effect the insulation's total R value, which indicates the thermal resistance of the material.

The highest priority for heat management is ceiling insulation, as this is greatest area of heat loss or gain. Insulation is better placed on the external building envelope, outside of any thermal mass.

Remember to carefully seal any gaps in the insulation. A small gap can loose a great deal of benefit!

Minimum Insulation Levels Climate Wall R value

Ceiling R value

Cool Temperate and Alpine Melbourne, VIC Canberra, ACT Hobart, TAS

3.7 4.3 4.3

2.2 2.4 2.4

High Humid and Hot Dry Darwin, NT Cairns, QLD

2.7 2.7

1.9 1.9

Warm/Mild Temperate and Warm Humid Brisbane, QLD 2.7-3.0 Perth, WA 3.2 Alice Springs, NT 2.7 Sydney, NSW 3.2-3.7 Adelaide, SA 3.2

2.2 1.9 1.9 1.9-2.2 1.9

Insulation materials

Material

Mineral fibres

Brick Hardwood (most) Straw bale Fiberglass batts Cellulose wet-spray Cotton batts Polyethylene foam Molded expanded polystyrene (EPS) Polyurethane rigid panel Vacuum insulated panel Cardboard Thinsulate clothing insulation Poured concrete Glass Polystyrene board Air-entrained concrete

Either made from the spun fibres of fibre glass (glass wool) or volcanic rocks (rock wool). Its available as batts and blankets. Rockwool is

Cellulose Made from shredded waste paper and sold as a loose fill which is then blown into the roof cavity, so you can't DIY.

Polyester Sold in batts and blankets.

Fire and insect resistant.

Sheeps wool Fire resistance of pure wool products can vary quite alot.

Massive price fluctuations between suppliers.

Other materials Include polyurethane and polystyrene foam boards, mineral loose-fill granulates (Perlite, Vermiculite), reflective foils, multi-cell, multi-layer laminated foil batts and combinations of different materials, such as glass wool batts with reflective foil on one side.

• Fire and insect resistant.

• Easy to install yourself • Can cause short-term irritation to skin, eyes and respiratory tract. If you install these products yourself, wear protective clothing.

• Price can fluctuate between suppliers so shopping around is strongly advised.

• Borax and boric acid are used to coat the paper to make it insect repellant and fire retardant.

• Quite eco-friendly.

• Made from petrochemicals.

• Gives off a dense, toxic smoke if it melts in a fire.

• Better insulation properties than similar mineral fibre products.

Made from new and waste wool and is often combined with polyester. It is generally sold as a ceiling fill which, like cellulose must be blown into your roof or wall cavity a your supplier.

R value per inch R-0.2 R-0.71 R-1.45 R-3.1 R-3 R-3.7 R-3 R-3.7 R-6.8 R-30 R-3 R-5.75 R-0.08 R-0.24 R-5.00 R-3.90

Source: Wikipedia

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Water and garden: Where water goes

As the planet's most arid inhabited continent, Australia can provide only a limited amount

Water Heating 23% Cooking 5% Standby 5% Lighting 11% Refrigeration 12% Heating & Cooling 20% Other Appliances 24%

of fresh water. Resources are expected to decline with changes to rainfall patterns accompanying global climate change. As our population grows, so too does the pressure on water use.

Good design can greatly reduce the amount of water we use and the degree of contamination we cause, and there are a number of ways that water can be used in a

Precautions for your grey water

sustainable way. The application of each of the following ideas will depend on whether you live in the city or the country, in the

•

tropics or the warm temperate south. Examine the options presented and decide which design

• •

solutions would improve your quality of life and reduce your

•

impact on the environment.

Fertilisers, detergents and washing powders may run-off or leach through the soil to enter waterways, contributing to algal blooms and other water quality problems.

Soils and plants may become water-logged and inhibit growth.

Soils can become clogged with organic material or damaged by salts in the wastewater.

Salinity may increase from using washing powders with a high salt content.

Choosing a water tank • Above ground tanks are usually the most affordable. Consider slimline and wall line tanks that can fit into narrow spaces.

Disinfection Eco-friendlier UV steriliser.

Treated water to house plumbing

Source water in

filter Electric power supply

High out-put UV lamp

Disinfection is required for indoor reuse of greywater. All disinfection systems require regular maintenance.

Chlorine is most commonly used for disinfection. However, chlorine disinfection has been found to have adverse environmental impacts. Alternatives should be used where possible, such as ultraviolet (UV) or ozone disinfection in place of chlorination.

• Underground tanks save on space and have greater catchment potential, but can be more expensive and require excavation.

Consider modular systems that capture water via infiltration through the grass lawn or garden.

• Underfloor bladders save on space and may have greater catchment potential than above ground tanks.

Consider sealed flexible bladders which can be installed side by side or end to end depending on space.

Above ground tank

Under ground tank

• Calculate the rainfall in your area and you're home's monthly water use to asceratin the tank volume required for your needs.

Bladder tank

Treatment Systems

Grey water

Biological greywater treatment systems for indoor use require a multi-step process. Firstly, coarse filtration removes large particles to prevent clogging. Fine filtration and biological treatment follows, to break down organic matter. Check with your council or state health department to determine which systems are accredited for use in your area.

The most common wastewater treatment system for outdoor reuse in Australia is the aerated wastewater treatment system (AWTS). The system assists bacterial breakdown of organic matter, and requires a further stage of disinfection (usually using chlorine pellets). There are many commercially available models in all states.

Greywater can be directly diverted from the shower or bathroom for immediate reuse in the toilet. Reusing treated greywater for toilet flushing can save approximately 50L of potable water in an average household every day.

The grey water does require some basic treatment before being used on the garden or for clothes washing.

Small wetlands can be built in residential areas to provide a natural treatment system for the grey water. These generally include a pond and reed bed that the water passes through after it was passed the course filter stage. The reeds and aquatic plants remove the particles, pollutants, nutrients and bacteria prior to the water entering the wider garden area.

Home grey water cycle

Roof-top grey water storage tank

outdoor use Laundry W.C.

Bathroom

UV filter Sand filter with reeds Coarse filter and surge tank Pump

To sewer or septic tank

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Green roofs & walls: From the turf roofs of Viking dwellings in Scandinavia to the ‘hanging’ gardens of ancient Ba-

Green roof Growing medium

bylon, green roofs have a history reaching back thousands of years.

Gravel

Modern green roofs and walls are

Drain

building elements designed to support living vegetation in order to improve a building’s performance.

Also known as ‘living’ roofs and

Filter paper

Root barrier Root barrier Root barrier

walls, they are emerging as important additions to the palette of construction techniques for creating healthy, ecologically responsible buildings.

Green roofs are an accepted part of modern building in Europe where some city and even national governments have mandated their use.

Australian examples are less common but in 2007 a national organisation was formed to promote green roofs and Brisbane City Council included green roofs in its proposed action plan for dealing with climate change.

The green roof has many benefits beyond the aesthetic.

The soil, plants and the water embodied in these structure provide a highly insulating barrier with significant thermal mass.

They increase biodiversity and reduce the 'heat sink' effect of densly populated areas, whilst filtering air pollutants and proving accoustic insulation properties.

Green roofs and walls can treat grey water from showers, baths and hand basins.

Water efficiency in the garden is a must, so be sure to choose eye-catching water-wise native plants.

The green roof or wall should also be considered as a prime food growing resources. Sustainability coach Michael Mobbs

says 'A garden on a balcony, window sill or as a vertical garden on a wall can provide many herbs, beans, fruits and greens – between five and 100% of a person's food depending on their diet and gardening experience.'

Growing food organically provides free and tasty produce while also reducing food miles, water use, agricultural land dependence and reliance on chemicals and pesticides.

It is also a good idea to consider the location for wastewater, compost and worm farms so they integrate smoothly into your garden and green roof.

The green roof concept can easily double for vertical gardens, meaning there is no end to the amount of building exterior that can be turned completely green!

How green roofs work There are typically seven layers to a green roof: •

Waterproofing membrane.

Modified bitumen or plastic sheeting most typical.

•

Root barrier (polyethylene sheeting, copper or copper compounds in the membrane).

•

Insulation (optional).

•

Drainage layer (synthetic drainage mesh or granular aggregate).

•

Filter fabric (geotextile).

•

Growing medium – also known as planting

•

medium or substrate (manufactured soil, crushed brick or other inorganic material).

•

Vegetation (shallow-rooted on extensiveroofs, deeperrooted on intensive roofs).

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Indoor air quality As most of us spend more than 90 per cent of our lives indoors. it is worth thinking more closely about air quality in our homes. This fact sheet discusses the likely sources of indoor air pollutants and the possible associated health conditions. it provides advice and actions that you can take to protect the health of people living in your home.

This fact sheet will also help you make better-informed decisions about health and indoor air quality issues when discussing a new build or renovation with your architect, designer, builder or building material supplier.

Poor indoor air quality may cause a range of health effects from mild and generally non-specific symptoms such as headaches, tiredness or lethargy to more severe effects such as aggravation of asthma and allergic responses. Most of these conditions can also arise from a number of different causes other than the quality of the air in your home.

Indoor air pollutants Common sources of indoor air pollutants include building operations and construction materials, household products, various human indoor activities as well as external factors (from outdoors).

A person is most commonly exposed to air pollutants when they breathe in an air pollutant or allergen. Exposure to an air pollutant by swallowing or through the skin may occur in some circumstances.

Mould

Mites

Pollen

Pet dander Food Smoke

Mildew Chemicals

Volitile Organic compounds Volatile organic compounds (VOCs) are chemicals containing carbon that evaporate into the atmosphere at room temperature.

They often have an odour and are present in a wide range of household products, construction materials and new furnishings.

Household products that contain VOCs include paints, varnishes, adhesives, synthetic fabrics, cleaning agents, scents and sprays.VOCs can also occur as a result of personal activities, such a smoking.

When used in building products or other indoor items VOCs slowly make their way to the surface and ‘offgas’, into the surrounding air. Most offgassing occurs when products are new and/or freshly installed, after which it lessens dramatically over time.

Paint Lead paint is most likely to be found in homes built before 1970. Paints containing up to 50 per cent lead were commonly used on the inside and outside of houses built before 1950.

Up to the late 1960s paint with more than 1 per cent lead was still being used. Regulations have reduced the levels of lead in paint to 0.1 per cent.

Commercial home test kits are available from some hardware stores. For more reliable results, use the services of an analytical laboratory. If you do find lead in or around your home, phone your state or territory public health unit for advice.

Embodied Energy Guidelines for reducing embodied energy

Embodied energy is the energy consumed by all of the processes associated with the production of a building, from the mining and processing of natural resources to manufacturing, transport and product delivery. Embodied energy does not include the operation and disposal of the building material. This would be

•

Design for long life and adaptability, using Modify or refurbish instead of demolishing or adding.

•

Ensure materials from demolition of existing buildings, and construction wastes are reused or recycled.

•

Use locally sourced materials (including materials salvaged on site) to reduce transport.

•

Specify standard sizes, don’t use energy-intensive materials as fillers.

•

Select materials that can be re-used or recycled easily at the end of their lives using existing recycling systems.

•

Give preference to materials manufactured using renewable energy sources.

•

Use efficient building envelope design and fittings to minimise materials (eg. an energy efficient building envelope can downsize or eliminate the need for heaters and coolers, water-efficient taps allow downsizing of water pipes).

considered in a life cycle approach.

Embodied energy is the ‘upstream’ or ‘front-end’ component of the lifecycle impact of a home.

This fact sheet discusses the

Life Cycle Assessment blurb

relationship between embodied energy and operational energy. It then discusses the embodied energy of common building materials and guidelines to consider when reducing embodied energy impacts.

The single most important factor in reducing the impact of embodied energy is to design long life, durable and adaptable buildings.

Embodied energy of materials

Embodied Energy (GJ)

Recycling after use.

Reuse of materials saves about 95 per cent of embodied energy. Savings from recycling of materials varies, with up to 95 per cent for aluminium but only 20 per cent for glass.

Embodied energy (MJ/kg) 250

MDF

11.3

Plywood

10.4

Synthetic Rubber

10.4

Acrylic Paint

61.5

150

50

100

4.4

PVC

80.0

Imported dimension granite

13.9

50

25

0

0

Glass

Steel

Stone

Ceramics

170

Plaster

12.7

Aluminium

Glass

Glass

Fabric

100

Masonry

5.6

Copper

Plastic

4.4

Cement

Concrete

Plaster board

Embodied energy savings (%) 100

Timber

Plastics- General

200

8.0

Copper

Particle board

2.0 24.2

Aluminium

Hardboard

Steel

Kiln dried sawn hardwood

3.4

Stainless st.

Kiln dried sawn softwood

Aluminium

Material

Life Cycle Assessment (LCA) examines the total environmental impact of a material or product through every step of its life – from obtaining raw materials (for example, through mining or logging) all the way through manufacture, transport to a store, using it in the home and disposal or recycling.

LCA can consider a range of environmental impacts such as resource depletion, energy and water use, greenhouse emissions, waste generation and so on.

LCA can be applied to a whole product (a house or unit) or to an individual element or process included in that product.

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Materials It is important to be aware of

Building Materials

the economic and environmental cost of various commonly used materials. There are various tools available for measuring embodied energy and principles for choosing materials and systems to reduce or eliminate impacts.

Careful analysis and selection of the materials used and the way they are combined can yield significant improvements in the comfort, cost effectiveness and energy efficiency of a home. Informed decisions about materials and construction systems can reduce the environmental impact of a home without adding to the cost.

Here are some quick tips

Mud bricks are made by mixing earth with water, placing the mixture into moulds and drying the bricks in the open air.

to reduce the total amount of materials consumed and their environmental impact: • Design and build for deconstruction, re-use, adaptation, modification and recycling.

• Make more efficient use of existing materials.

• Use fully recycled materials or materials with recycled content.

• Choose materials with a lifespan equivalent to the projected life of the building.

• Encourage development of new, efficient, low impact materials and applications by creating demand.

• Consider how and where the materials are sourced and the impacts this causes.

• Minimise the energy used to transport materials by using locally produced material.

• Use of lightweight material where appropriate also reduces transportation energy.

• Minimise the energy used to heat and cool the building by using materials that effectively modify climate extremes.

• Understand how chemicals used in the manufacture of some materials might affect your health.

Lightweight timber is the most common house construction timber type. It has the potential to provide a renewable building material that stores carbon in its production.

Rammed earth walls are constructed by ramming a mixture of selected aggregates, including gravel, sand, silt and a small amount of clay, into place between flat panels called formwork.

Clay brickwork is made from selected clays that are moulded or cut into shape and fired in ovens, transforming it into a building component with high compressive strength and excellent weathering qualities Thermal mass is the ability of a material to absorb heat energy. A lot of heat energy is required to change the temperature of high density materials like concrete, bricks and tiles. They are said to have high thermal mass.

Lightweight materials such as timber have low thermal mass.

Poor use of thermal mass can exacerbate the worst extremes of the climate and can be a huge energy and comfort liability. It can radiate heat all night during a summer heatwave, or absorb all the heat you produce on a winter night.

Thermal Mass

Straw can be used as a building material for thatch roofing and also boasts excellent insulation properties when used in walls. called formwork.

Autoclaved aerated concrete (‘AAC’) is effectively concrete with lots of closed air pockets in it, produced by adding a foaming agent to concrete in a mould,.making it lightweight and energy efficient