Energy Efficiency and Sustainability for Housing

There are a range of Design Assessment Tools to measure environmentally sustainable design and energy efficiency. Some of the most common Tools include:

BESS (Built Environment Sustainability Scorecard)

BESS is an online sustainable design assessment tool. It is:

• A free tool for planning applicants to use
• Assesses all types of buildings of all different sizes, including mixed use developments
• Is an easy and straight forward program to use
• Can be used as a bench marking tool against other developments
• Assists with reducing the running costs of new buildings
• Provides a range of liveability and useability benefits for building owners and users
• The information required to complete a BESS Assessment depends on the nature of the proposal; simpler applications require more basic information, whereas larger, more complex applications require more detailed information.

For more information visit the BESS website.

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STORM (Stormwater Treatment Objective - Relative Measure)

STORM is a free tool which assesses storm water management qualities. The purpose of STORM is to assess whether best practice water quality objectives can be achieved as part of a development. STORM is managed by Melbourne Water.

For more information visit the STORM website.

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NatHERS (Nationwide House Energy Rating Scheme)

NatHERS is a star rating system (out of 10) which determines the energy efficiency (heating and cooling) of a dwelling, based on the design of the dwelling. It assists with meeting the requirements of the National Construction Code. The purpose of NatHERS is to assist with designing homes which are more comfortable for inhabitants and to reduce the operating costs of the dwelling.

For more information visit the NatHERS website or view a short video on YouTube explaining Energy Efficiency at Home.

The orientation of your dwelling and its individual rooms can play a significant part in the ongoing operating costs of your home and the comfort of your family. Depending on the season, the position of the sun varies. It is important that you position your dwelling to take advantage of these sun variations. Good orientation and siting can reduce your dwellings use of energy for heating and cooling purposes, which in turn can reduce energy bills and increase comfort levels within the home.

Consider the following when orientating and siting your dwelling:

• Locate living areas and windows to the north of the dwelling to take advantage of the winter sun and reduce exposure to the summer sun.
• Position utility areas, such as bathrooms and laundries (where typically less time is spent) to the south or west side of the dwelling.
• Minimise the number of windows on the south, east and west sides of the dwelling.
• Avoid locating bedrooms on the western side of the dwelling, as this will lead to an uncomfortable night's sleep. Instead locate bedrooms to the south of the dwelling to enable better sleeping conditions.
• Site your dwelling with the southern and western walls as close as possible to the boundaries of the land to allow the northern and eastern areas to be used for outdoor living and gardens.
• Position your garage or carport on the western side of the dwelling to reduce the exposure of sun to the western side of the dwelling. Avoid placing any obstructions on the northern side.
• West facing walls receive the strongest sun during the hottest part of the day in summertime.
• Incorporate a large expanse of north facing roof to allow for optimising the positioning of solar panels and hot water panels.
• Ensure that north facing walls and windows are well setback from other large buildings or trees to minimise the extent of overshadowing.
• Strategically locate plantings to ensure that larger trees and shrubs do not result in overshadowing.

The materials you use to construct your new dwelling or addition can have a significant impact on the carbon footprint of the building, and also how energy efficient the building will be. It is important to consider your building materials up front because it can be difficult and more expensive to retrofit an existing building. In addition, while the initial costs may be higher in order to incorporate these materials, they can pay off over the lifetime of the building.

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Insulation

• All building materials allow heat to pass through them. Insulation helps to reduce the transfer of this heat depending on the seasons.
• Using insulation in your building can assist with minimising heat loss in winter and preventing heat gain in summer.
• In winter, insulation acts like thermos and keeps the heat in, and in summer, it acts like an esky to keep the heat out.
• Insulation should be incorporated throughout the building, including in the ceiling, roof, walls and floor.
• Insulation is most effective in conjunction with good building orientation and siting on the property.
• Common types of insulation include polyester batts, polystyrene sheets, glass wool batts and sheep's wool batts.
• Insulation comes in two main categories - bulk and reflective. To determine the effectiveness of each different type, we need to measure their resistant to heat flow, which is known as their R-value. A higher R-value will result in a higher level of insulation.
• Renovations are often an ideal time to install new insulation in your floors and walls.

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Thermal Mass

• Thermal mass is the capacity of building materials to store and absorb heat, and then release it at a later time.
• During the summer, the heat is absorbed and released at night to cooling breezes or the clear night sky, ensuring the building does not get too hot, while in winter, the heat from the sun is stored to be released internally at night, to assist with keeping the building warm.
• Different materials have different thermal mass - brick, concrete or straw bale typically have a higher thermal mass, while weatherboard and corrugated iron have a lower thermal mass.
• Like insulation, thermal mass works best with good building design; glazing facing appropriate directions, appropriate levels of shading, insulation and thermal mass.
• When used appropriately, thermal mass can make a big difference to the interior comfort of a building and can minimise the need for mechanical heating and cooling.

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Construction Materials

• It is important to consider the materials you use when constructing your building, as different materials can have a different impact on the environment.
• Each material has a different amount of embodied energy used to produce it (from raw resource extraction, its manufacture, and transporting and delivery of the material).
• It is important to use a range of different materials in the construction of your building. You should look at incorporating certain materials to enable a high thermal mass, but also using other materials to which enable low energy consumption.
• If you are demolishing an existing dwelling, it is beneficial to use existing building materials such as bricks, timber and windows.
• The majority of new buildings use new materials, which is not always environmentally friendly. Incorporating materials that traditionally have a longer lifespan is better for the environment.
• Materials which are produced locally can assist with reducing transport omissions.
• Different building materials have different benefits, and it is important research which construction material will have the best environmental benefits for your building.
• Some common building materials include brick, concrete, corrugated steel, weatherboard, straw bale, mud brick, rammed earth, autoclaved aerated concrete (AAC) and earth brick.

Windows play an important part in the makeup of a dwelling. Windows let in air to cool and ventilate a dwelling, as well as natural light to provide a comfortable living environment. They also enable views of the outdoors and connect the interior and exterior of dwellings. It is important to appropriately design and locate your windows to take advantage of these benefits, and also in order to reduce heat gain in summer and heat loss in winter.

• Windows which are appropriately designed and located can assist with making your home more comfortable, help to reduce your energy costs, and create brighter and comfortable living areas within the home.
• Windows on the northern elevation should be maximised, and shaded with eaves or other shading devices.
• On the southern elevation, the number of windows should be minimised, however there should be enough openings to allow for cross ventilation throughout the dwelling.
• Windows on the east of the dwelling should be avoided, however if required, should be as small as necessary. These windows need to be provided with external shading.
• Like eastern windows, western windows should also be avoided, or minimised. The western side of any dwelling will be exposed to the strongest sun at the hottest time of the day.
• Locate windows to allow for cross-ventilation throughout your dwelling. In summertime, this will enable the evening summer breezes to flow through and help cool your dwelling.
• When choosing your windows, it is important to consider the type of glass, the window frames, and any window coverings, as this assists with improving the energy efficiency of your dwelling.
• Installing double glazed windows can help to reduce the amount of heat gain in a dwelling during the summertime and reduce the amount of heat which is lost in the wintertime.

Shading of your dwelling and outdoors spaces can assist with reducing summer temperatures, improving the comfort of your building, and saving energy. The shading of glass is critical to assist with minimising heat gain, as one of the greatest sources of heat gain in a dwelling is unprotected glass. Once heat passes through the glass, it becomes absorbed by building materials and furniture, effectively becoming trapped and creating a greenhouse like effect.

• Effective shading can include eaves, shutters, window awnings, pergolas and plantings.
• Eaves which are correctly designed can be some of the simplest and cost-effective shading methods on the northern elevation of your dwelling.
• When choosing the appropriate shading devices, ensure that they are effective in reducing the summer heat, but that they do not block out the winter sun. Installing adjustable shading devices will allow for seasonal variation.
• External shading of windows is more effective than internal shading, though combined will give the best results.
• External shading devices help to reduce the transfer of heat through the fabric of the building. Internal shading devices can assist with reflecting a small amount of heat which has already penetrated the buildings fabric. However, once the heat is already in the building, it is harder to enable a more comfortable building temperature.
• The most efficient types of shading differ depending on the orientation of your windows.

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North facing windows

• Fixed horizontal shading devices such as eaves and pergolas.
• Adjustable external shading such as awnings, blinds and roller shutters.

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East and west facing windows

• East facing windows can be a major source of heat gain in the morning during the summertime, while in the afternoon, it is the west facing windows.
• Best shaded by adjustable external shading devices such as awnings, blinds, louvres, shutters or angled metal slats. Having adjustable devices allows flexibility to make adjustments as required by weather conditions and comfort levels.

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South facing windows

• Don't require shading in summer to the same extent, as they receive very minimal sunlight. South facing windows are best used for ventilation purposes.
• In wintertime, south facing windows can lose heat, so windows should be double glazed, and heavy curtains and pelmets should be included in design.

The purpose of solar panel systems is to harness sunlight in order to generate electricity. The rising cost of electricity has left many homeowners worried about future electricity costs, and many are turning to solar panels in order to reduce energy bills. Others are also looking to install solar panels to produce greener energy and be environmentally friendly.

• To determine what size solar panel system you need, you need to work out how much electricity you use, and at what times of the day you use it. To do this, check previous electricity bills.
• Different days, times and seasons will require different levels of usage ie. usage is typically higher on weekends when more people are at home, summertime means extended air conditioning use, while in winter, the heater is often running.
• A typical Australian home uses 20kWh of energy a day, which equates to a 5kWh system.
• The number of panels installed is actually irrelevant; it's about the overall capacity of the system that you install as to the success of the system.
• If you choose panels with a higher power rating (and therefore a higher output), you will need less panels. However, if you have more roof space available to install the panels, sometimes it can be more economical to purchase cheaper panels that have a lower energy efficiency individually and install more of them.
• In Australia, solar panels work best when they are facing north, as this is the optimum direction for catching sunlight. North facing solar panels generate more electricity, which in turn assists with lowering energy bills.
• It is important to ensure that there are no trees, structures or power lines which could result in the shading of the solar panels.
• There are two main components to the solar panel system; the panels themselves, and the inverter (the part that enables the electricity generated by the solar panels to be converted to use in household circuits to power your television, fridge, air conditioner etc). Some people also chose to install a battery to store any surplus energy for future use as required.
• In Australia, we have grid-connected and off-grid solar systems. Grid-connected are the most common and are those systems which are also connected to the main electricity grid. During the day, the power generated from the solar panels is used, and at night, or on days when there is less sunlight, the main electricity grid can be used (if no battery is installed).
• The off-grid system is a complete stand-alone system, and all the power for the dwelling comes from the solar system (though sometimes from other sorts of power generation, like wind, and in some instances, generators can also be used).

Water Sensitive Urban Design (WSUD) integrates water cycle management into the built environment (ie. into planning, design and construction).

Often, our waterways are filled with chemicals and pollutants from stormwater, causing them long term harm. WSUD recognises that waterways are an important asset and need to be protected. By incorporating WSUD measures into our developments, we can reduce the negative effects of stormwater on our waterways.

WSUD measures can be implemented at any scale of development, from the single dwelling level to large scale developments and subdivisions. Common types of WSUD include rain gardens, porous paving and rainwater tanks.

A well-designed dwelling or addition helps to reduce water usage, finds ways to take advantage of water that is captured on site, and can assist with improving water quality for water which flows back into our important waterways.

Water Sensitive Urban Design recognises that all water streams in the water cycle are valuable resources including rainwater (collected from the roof), runoff (including stormwater, collected from all impervious surfaces), potable water (drinking water), groundwater, grey water (water from bathroom taps, showers and laundries) and black water (from toilets and kitchen sinks). Some examples of WSUD measures are outlined below.

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Rainwater Tanks

• The purpose of a rainwater tank is to collect and store stormwater captured from roofs, downpipes and gutters.
• Rainwater tanks have become a common site across Victoria in recent years, and they come in a range of shapes, sizes and colours.
• Rainwater tanks enable the conservation of mains water.
• Their installation can help to reduce water bills through water reuse.
• Rainwater tanks help to treat stormwater and protect local streams from pollutants which are produced from residential uses.
• Tank water can be used to water gardens, wash clothes and flush toilets, which assists with reducing the demand on drinking water.

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Raingardens

• Raingardens are specially designed garden beds that use plant and soils to help with the capturing, filtering and cleaning of stormwater.
• They assist with minimising stormwater runoff to stop pollutants entering our waterways.
• Raingardens have layers of mulch, planting (native plants work well, but any species can be used) and soil, with a drain underneath to reduce flooding risk.
• Rainwater gardens can come in different forms including planter boxes, in-ground, swale, and vegetable gardens.

Raingardens work in the following manner (Source: Melbourne Water):

• Water collects and settles on the garden surface.
• Water soaks through the plants and filter media, trapping rubbish and sediment on the surface.
• Plants use the nutrients in the stormwater, and toxins stick to the soil.
• The soil and plant roots work together to naturally filter the water and remove pollutants.

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Porous paving

• Paved surfaces including roads, footpaths, driveways and courtyards cover a significant area within our environments.
• A lot of these surfaces are impervious, which means that rainwater cannot pass through them into the ground below. Instead, it runs off into the stormwater, carrying pollutants into our waterways and putting additional pressure on the stormwater system.
• To stop this occurring, we need to reduce the amount of 'impervious surfaces' by incorporating porous paving, which comes in a range of styles and finishes (ie asphalt, modular pavers that are concrete, ceramic or plastic).

Incorporating environmentally sustainable and energy efficient design principles into subdivisions is important to ensure ongoing sustainability in Victoria's towns and communities.

This information outlines the environmental sustainability and energy efficiency of subdivisions, rather than the actual dwellings/buildings which will be constructed within the subdivision. Incorporating environmentally sustainable design and energy efficiency measures in subdivisions can be undertaken at a range of different subdivision scales. Often such measures can be selling points for potential homeowners.

Good Environmentally Sustainable and Energy Efficiency design elements for subdivisions include:

• Pedestrian and cycling friendly neighbourhoods that allow easy access
• A well-integrated network of open space
• The use of recycled water and Water Sensitive Urban Design (WSUD) measures
• Higher density housing located around activity centres, and the incorporation of shops and mini retail centres, playground equipment and parks, and schools
• Lot layout which allows for optimum solar orientation, including orientation of public open space
• A diversity of lot sizes to accommodate a range of dwellings
• The use of drought tolerant plants and indigenous species
• The use of low energy street lighting
• Footpaths on both sides of the street to enable active travel
• Good access to community facilities and public transport options

Case Studies:

• The Cape, Cape Paterson, Victoria
• Mullum Creek, Donvale, Victoria
• YarraBend, Alphington, Victoria
• Witchcliffe Ecovillage, Margaret River, Western Australia
• Lochiel Park, Campbelltown, South Australia

Source: Environmentally Sustainable Design for Subdivisions in Regional Victoria (AECOM)

The following are some ESD and Energy Efficiency Case Studies:

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The Cape at Cape Paterson

The Cape at Cape Paterson is located in Cape Paterson, about 140km southeast of Melbourne, approximately 10 minutes from Wonthaggi. The vision of The Cape is to create a benchmark for sustainable living, with dwellings required to achieve a minimum 7.5-star energy rating. For further information on The Cape, please visit The Cape website.

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Sustainable House Day

Sustainable House Day encourages members of the public to visit some of Australia's most sustainable houses. To explore some of these dwellings, please visit the Sustainable House Day website.

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Your Home

For some other examples of best practice sustainable design and construction, please visit the YourHome website.

• Sustainability Victoria website
• Energy Smart Housing Manual (Sustainability Victoria)
• Council Alliance for a Sustainable Built Environment (CASBE)
• Your Home
• BESS
• STORM
• NatHERS
• Environmentally Sustainable Design for Subdivisions in Regional Victoria
• Smart Living at Home - A Guide to Sustainable Building and Renovating
• Green Building Council Australia
• Sustainable House Day
• Environment Victoria
• Your Energy Savings
• Energy Rating
• Victorian Energy Saver
• Melbourne Water (Water Sensitive Urban Design - WSUD)

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Heritage and Environmentally Sustainable Design (ESD)

The Victorian Department of Environment, Land, Water and Planning (DELWP) provides a range of Guidance Sheets on heritage places and environmentally sustainable design.

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What is Wellington Shire Council doing?

For more information please visit Council's Sustainability page.