COOLmob Design Booklet

8/12/2019 COOLmob Design Booklet

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Greenhouse Friendly

Design for

the Tropics

By Steve Beagley


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AcknowledgementsThis book could not have been written without my willing band of helpers. Support anddrive to keep me going came from Program Manager, Robin Knox, and the rest of themob. Thanks to Derrick Wrigley for inspiring me to write this book. Also, thanks to Jan

and Carolyn, for editing and proof reading my work - a big task for them!A special thanks to Sally Heinrich, better known as an illustrator and author of booksfor children, than of building illustrations. This was a dicult task as she had to workfrom my rough sketches and altered photos, and was helped with input from Sandra.

Finally, thanks to my wife, Penny, for the time we spent driving and walking the streetslooking for the bad examples of tropical design.

Disclaimer

The content of this publication does not necessarily represent theposition of our sponsors.

This book is designed to be read in conjunction with the COOLmob GreenhouseFriendly Hardware for the Tropics and COOLmob Greenhouse Friendly Habits in theTop End Booklets.


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Chief Ministers Foreword 2Preface 3

Why Sustainable Design? 4

Getting Started 6

The Structure 17

Outside 28

Inside 33

Why This Book Was Written 39

Contents


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Chief Minister,s Foreword

Congratulations to COOLmob on developing this wonderful communityresource for Territorians. It complements the actions being taken by myGovernment in its Greening the Territory initiative. Whether you are building,

buying or selecting where to rent, you will nd this book useful.

The material presented here will ensure that you have useful information whentaking your rst step towards choosing your own home. You can make informeddecisions now that will save considerable money over the coming years in lowerpower and water bills.

A well designed house does not require lots of additional cooling and will increase yourcomfort and quality of life. By taking into account the information presented here youcan also live more sustainably and reduce your carbon footprint on our planet.

This book compliments the COOLmob Greenhouse Friendly Hardware andGreenhouse Friendly Habits books also produced by COOLmob.

Paul HendersonApril 2011


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Preface

In 2007 COOLmob developed ahousehold comparison system basedon the number of kilograms of carbon

dioxide (CO2) being emitted perperson per day from homes we hadalready audited. Apart from thosehouseholds on the extremities, wewere able to decide on a close tstraight line from the graph giving a0-10 star rating (0 worst cases) withthe mid range households being 5.(Appendix 1.1)

COOLmob has increased our areas ofaudit coverage to include the newersuburbs of Palmerston and more ofthe ground level private homes in thenorthern suburbs. In these areas wehave found a tendency for the houses tohave increased consumption of energyper person per day. The new designs arerelying far too much on unsustainable,consumptive technologies. Take note ofthe number of air conditioners now beinginstalled in these new homes instead ofadapting the design to our climate.

It is estimated the average householdwith air conditioning (one in eachbedroom and one in the lounge room)

will spend approximately $60,000(Appendix 1.2)on power costs overthe next ten years and produce over145 tonnes of greenhouse gases withthis level of consumption.

We believe that the current trends inhousing design and the increased use ofelectrical appliances need to be reversed.Only by doing this will we be able to

lessen our impact on the environment andreduce the amount spent on electricity.COOLmob has identied a need for morepublic advice in this area so this booklethas been produced to help the public:

To identify positive and negativefeatures of houses with regards toenergy consumption when designing,building, modifying or renting homes.

To reduce their costs and thecarbon footprint they producethrough the amount of energyconsumed in their home.


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Why sustainable design?

For centuries humans have knownhow to build houses that utilise theelements to achieve comfortable

living conditions.

In the Middle East, adobe houses werethe order of the day. They were built tocatch breezes, utilise the cooling eectof water and their design and orientationlimited the ingress of direct sunlight,

Even Australias European settlers,limited by the available building materials,

built houses that opened up to allowthrough-ventilation, despite being madefrom galvanised iron. They used simpleconcepts such as high pitched roofswith vents that maximised the gain frominduced ventilation.

So why is it that today, with all theadvances in science, technology andmaterials, we build houses that require

such high amounts of energy to provideacceptable living conditions?

As a society we now demand betterliving conditions as standard. Howeverour increased energy consumptionfar outweighs the improvement inconditions. We have forgotten what ourforbearers taught us! Relying only on airconditioning to cool your home is as

logical as running a refrigerator insidean oven.

The negative eect on our environmentcaused by this increased energyconsumption will increase. We all have

Windcatchers,Yazd, IranBreezes are directed down intothe houses and the hot air forcedout on the downwind side.

Ice storage, Abarqu, IranDuring hot summer months ice wasstored in these mud structures withoutthe need for the energy consumingcomplex refrigeration systems of today.

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a responsibility to the environment.Just because someone can aordhigher power costs or because we are

compensated for the provision of the airconditioning doesnt mean we should beusing it.

It is now time to revisit some of thehistorical knowledge of our ancestors.By doing so, we can reduce ourconsumption, save money and helpour planet.

A win/win situation, how gooddoes it get!

The suggestions made in this booklet areprovided to help in your decision makingand with well-considered early planningreduce your ongoing power costs. Thismay ultimately give you a property with ahigher resale value as the impact of risingenergy costs really hit home.

TIP

Your home is probably the most expensivepurchase you will ever make. Careful thoughtand planning now can save you a lot of money

and future discomfort.


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Getting Started

This section provides information onthe important starting points for yourhouse, basic orientation and layout,

initial block choice, siting of yourhouse and getting the groundworkright. Get these right and you are onthe way to building a home with lowenergy use

Selecting a Block of LandDid you know that the way your house

sits on your block can have a bigimpact on your energy bills?

When looking to buy land ensure theblock will allow you to orientate yourhome in the direction that will minimiseheat load on your walls and catchprevailing breezes.

The main starting parameters areorientation with consideration of shade

and breeze:

1. North or south facing walls oerthe best opportunity for shading sunon windows and walls by the useeave overhangs which dont obstructbreezes.1

2. Ensure the layout/design of your homeis such that natural ventilation is used

to the maximum.

Look for

blocks facing a street running east/west that have long frontage and lessdepth, or

blocks facing a street running north/south that have less frontage to thestreet and greater depth, or

blocks facing streets aligned north-west/south-east or north-east/south-west that have equal frontageand depth. This will allow steps in

external walls that provide self-shading to walls from the low anglesof the afternoon sun, or alternatively,rotation of the house plan to orientatelong walls to the north and south

Have some idea of your house shapeand layout and make sure that youcan position it on the block for goodorientation. Do this before you buy

your block of land!This is the mostimportant factor in giving you a goodstart in minimising the carbon footprintof your home. Remember, the money yousave by buying an unsuitable block withpoor orientation may well cost you manytimes more in providing shading and/orcooling (energy) costs over the followingyears particularly as energy prices rise,and they will!

1Aynsley R (2006) Sustainable Housing in the Humid Tropics Part 3, Strategies for Design


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Its important to selectthe right block

Acceptable

Not acceptable

Acceptable providedself-shading wallsincorporated into thedesign

Investigation has shown that good blockdevelopments can be achieved. Somesub-divisions are being developed thatnot only specify the environmentalrequirements for each of the houses onthe sub-division but have also ensuredthat with correct block layout andthe retention of open spaces homesare guaranteed reasonable access toprevailing breezes.

With the current reduction in block size,reduction in space between houses,increased use of solid fences, andcombined with the increase in groundlevel houses the opportunity for housedesigners to make use of natural breezesis limited. The use of gaps in solidfences provides very minor increasesin available breezes and is really only atoken gesture.

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House Shape and StyleCorrectly orientated house, well shadedand designed to utilise the predominatebreezes.

Modern house designs are often irregularin shape with several external angles.Roofs that are more complex result inhigher construction costs as well asmaking the future installation of photovoltaic (PV) panels, solar hot water(SWH) systems and the collection ofwater for rain water tanks more dicultand expensive.

A simple rectangular design makes theabove additions much simpler. Providedthe orientation is correct, easier control

of the heat load on the building isavailable and maximum natural ventilationcan be achieved. In the following examplethe 900mm wide eaves on the southernsection of the house near the livingareas will provide shade to the walls andwindows from direct sunlight.

Start with a simple house shape


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Elevated versusGround LevelIn recent years, fewer elevated houseshave been built and the ground level

blockwork house has become morepopular. However, the elevated housedoes have a number of advantages fortropical living

The house takes up less space onthe block increasing your ability toorientate the house correctly, andalso freeing up space for plants andverandahs that provide external

shading.

The under house space can be used forcar parking, storage, laundry facilitiesand entertainment areas.

The area under the housealso acts as an under-coverplay area for children duringthe Wet Season.

Under house areas can be used forclothes drying during the Wet Seasoneliminating the need for an electricclothes drier.

Lightweight construction means thatthe walls cool down much quickeronce the heat source (ie the sun) hasset, than the heavier concrete blockconstruction.

The elevated house has the ability tocatch a breeze more easily than theground level house

These advantages are becomingincreasingly important as blocksizes reduce.

Conversely, the elevated house can havethe problem of heat gain through the

oor which will be discussed later.

Orientation and Siting ofyour HomeGood orientation is an essential start ifyou want a low energy consuming home.

In the future your home may have a higherresale value as we recognise the economicand environmental value in good decisionsbeing made at the design stage.

Poor orientation contributes considerablyto the heat load of a house. It adds toconstruction costs as verandahs, extendedeaves, insulation or other passive solutionsare required to oset the increased heat

gains. Gaining a good star rating for yourhome will be signicantly more dicult ifhandicapped by poor orientation.

To prevent low morning and afternoon sunfrom heating up the house, minimise the sizeof east and west facing wall areas and avoidwindows in these walls unless well shaded.

The top house clearly shows howcorrect orientation reduces the eect

of the sun on your house by reducingthe area of walls aected by the lowmorning and afternoon sun.


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The exposure of walls and windows onthe western and eastern sides of yourhouse can be critical. Research showsthat residential tree cover cooled surfacetemperatures in the relatively mild month

of October 1999 by up to 5 degreesCelsius. When applying the eects oftree shade on the eastern and westernsides of a single storey, 3 star energy-rated home, energy savings of up to50% per annum could be achieved. 2

For those living down south orientationis a compromise between avoiding the

summer sun and using the winter sun toheat your home; whilst here in Darwin it ismuch simpler.

For Darwin, east west orientation reducesthe heat load through the external walls

provided the eaves are of sucient widthto provide the wall shading. Even for anelevated house the size of eaves requiredis in the order of 900 to 1200mmdepending on which side of the house.This is a very minor increase in the costof a house.

TIPEvery home needs to be designed specically for the site that it is intended for.Design your house on an east-west axis (or within +/- 10) for less direct sun onyour walls and consequent heat gain. Ensure living areas are located to receive asmuch access to prevailing breezes as possible

Theface the streetmentality, highlighted by Derek F Wrigley in his documentClimate change needs housing change, sadly has also crept into much of the housingdesign in the newer suburbs and replacement houses in the older suburbs of Darwin.The double garage, front door, lounge room and main bedroom across the front isrepeated in house after house with little regard to the orientation or shading.

2 T Hall in his paper The Death of the Australian Backyard A Lesson for Canberra cited researchcarried out by L Plant for the City Council of Brisbane.Plant, L. (2006) Brisbane: beautiful one day, perfect the next - is there room for improvement?TREENET 7th National Street Tree Symposium, Adelaide.

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Ensure your home is located far enoughback from the street to enable plants toprovide shading, privacy and reduce thenuisance noise and light (both street andtrac) from the street. This will ensure

that you can live comfortably in your

home with adequate privacy withoutthe need for heavy drapes and curtainswhich severely restrict available breezes.The need to keep out street noise willresult in shut windows and therefore the

unavoidable use of air conditioning.

VentilationCooling through natural ventilationdemands a good exposure of the buildingand its windows to the dominant breezes.

However, with the

reduction in block size,

the increase in house size

the predominance of groundlevel houses

the reduction in the distance betweenhouses, and

the construction of solid fences toprovide privacy and to reduce noiseinterference,

your ability to catch the predominatebreezes is severely reduced. Research hasshown that with houses blocked togetherlike most houses are, the breeze ows

over the roof not penetrating down intothe house.

Solar orientationand extended eavesshade windows

Wet season sun Dry season sun


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3 Lee, S. S. (1998) Natural Ventilation and Medium Density House Forms in the Tropics, PhD Thesis,Institute of Tropical Architecture, James Cook University

4 Hall, T. The Death of the Australian Backyard A Lesson for Canberra

Pathway of breezes around and above closelypositioned ground level houses in new sub-divisionsThe dwellings in the newer suburbsare generally of deep-plan layout withsmall windows. Their design relies on airconditioning for them to be habitable.However, even if they had been designedfor natural ventilation, the reductionin width between the dwellings would

make this very dicult, especially inthose parts of Australia with subtropicalclimates. A study by Lee Su San (1998)3of suburban development in the Douglasarea of Townsville revealed that thenarrowness of the gaps between thehouses prevented airow around them,creating a heat island eect. Herstudies of actual buildings conrmed

previous experimental results fromwind-tunnel tests with models ofbuildings (Lee, Hussain and Soliman,1980). For single-storey dwellings with acomparatively narrow gap between them,the prevailing winds skim over the roofswithout exerting air pressure within the

gaps to force natural ventilation. Naturalventilation of houses from the wind isincreased if the buildings are two, ratherthan one, storey high. The problem wasexacerbated by the exhaust from the airconditioners and the dark coloured roofswhich absorbed, rather than reected,the heat.4

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Orientation/breeze conictOur hot climate demands high coolingloads during most of the year; thereforeminimising sun exposure should take

precedence over maximising windexposure (whenever they conict).In most cases, the conict betweenexposure to sun or prevailing breezesis a false one as there are several waysto deect breezes into buildings, evenwhen the building doesnt have the bestexposure to wind.

The use of Wing Walls is one method.

Simple solid panels located alongsidewindows redirects cooler breezes intothe home and also pulls the hotter air out(wing walls also accelerate the naturalbreeze speed, due to the dierencesof pressure they create). They can beconstructed as an architectural featureusing various decorative materials.Casement windows also provide a similaraction though on a lesser scale.

Some designs use this fact in a moreradical way. They involve a wing wallat the downwind end of the home (in

order to create a positive pressure zonethere) and another similar wing wall onthe leeward side (at the upwind end, tocreate a negative pressure zone); thisdesign ensures stronger cross ventilation.Casement type windows, large openareas of louvres and sliding doors/wallswill improve the catching of breezes.

Air conditioning is often used to achieve

comfortable sleeping conditions bylowering temperatures and humidity. Thenumber of operating hours required forair conditioning to achieve thermalcomfort can be substantially reduced(or eliminated) by careful design of newhomes, alterations and additions.

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Placement of Solar panelsThe simple roof line of an elevatedhouse with east west orientation suitsinstallation of solar panels. Vegetation onthe western end wall provides shade to themain bedroom in the afternoon while stillallowing cool breezes to enter the house.It also provides shade to the western endof the northern verandah in late afternoon.Minimal high vegetation on northern sideensures that solar equipment receivesmaximum sunlight between 10am and 3pm,the most productive sunlight hours.

TIPWe cant change the suns path, but we

can deect breezes.


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Size of house - Build better not biggerIn her article Size Matters5

journalist Jenny Brown nds thatAustralians have been building biggerhouses, an increase of 50m2since 1986.With block sizes being reduced this hasresulted in much less space around andbetween houses reducing the coolingand shading that can result from a welldeveloped garden. The larger houses areof course more expensive and certainlyless sustainable.

Think carefully about what you reallyneed. A bigger house means you will haveless garden space and more house to

cool, light, clean and furnish. This adds to

your costs both now and in the future.Smaller well designed houses can fullour needs and result in savings of up to1 tonne of carbon emissions per year.

In the US, pressure on available land isprompting the beginning of what appearsto be a rationalisation of house size.American based architect Sarah Susankain her book The not so big house saysBuild better, not bigger and scale is therst consideration of sustainability.

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A wide verandah ensures the northernwall is shaded all day.

As the northern wall is well protectedfrom the sun, dark colours could be usedwithout the wall absorbing heat from thesun. The lined ceiling, (also tted withsisalation), reduces the radiant heat thatwould otherwise heat those sitting on theverandah and the walls.

Nearby vegetation creates an envelope ofcool air around the house and encourages

the circulation of cooling breezes.

5 Brown J. ATA Sanctuary Magazine - Issue 9Pages 84 and 85 Size matters


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Sustainable Living

For us to live sustainably we cannotcontinue to go on building these singledwellings on individual blocks creating

urban sprawl and massive transportationproblems. As the price of fuel rises so willthe cost of our transport. Although a lotof Australians dont like the idea we haveto increase the density of our living if wewant to live sustainably.

By denition, densication meansincreasing the number of units of housingper square metre of land, either through

building on vacant land or allowingtaller and larger structures but does notnecessarily mean smaller block sizes withour houses taking up a greater share ofthe block.

Densication should be a deliberatelyplanned and designed environment thatallows the better use of a given area

increasing the number of dwellings on thesite but improving the environment, bothphysically and socially. It can be achievedby the development of environmentallyfriendly low energy houses, in duplexform, eliminating the wasted and uselessspace between houses, having correctorientation, reducing the amount of spaceneeded for through trac and developingcommunity areas.

It is essential that this sensitive inlldevelopment occurs along ecientpublic transport corridors as part of therequirement is to reduce our reliance oncars and move away from the two car,double garage mentality.

This diagram is based on the samesub-division as shown on page 7.

The rst development had 46 sites, only28 of which were considered suitablebecause of being able to correctlyorientate the house. This alternativestyle of development has 49 suitablyorientated residences plus an area forpublic facilities and services. The densitycan be increased even further if sometwo-storey residences and multi-storeyunits are included in the high density area.

Minor roads

Pathways

Bus stop

Commercial Area

Community gardens

High density/multi-storey units

Carports


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The other suggested form of sustainabledensication is the development ofmultistorey units.

This does not however mean thecurrent approach of building multistorey

complexes lling most of the blockwith a building orientated only by therestrictions of the block boundaries andwhat is left of the block being covered

in concrete and bitumen to createstormwater and heat sink problems.Densication does not mean crammingthe maximum number of units intoa development just to maximise the

developers prot. Such a developmenthas a lot of ongoing costs both sociallyand nancially to both the tenants andthe community in general.

We need well designed, energy ecient and sustainable complexes adjacent toecient public transport and facilities, removing the heavy reliance on vehicles andthe need to provide excessive car parking. The complex design and layout should takeinto account noise pollution, stormwater control, grey water reuse and ensure that

heat sinks are not developed. Open green space should be developed between thesebuildings to provide social and community areas and facilities.

Windows on eastern and westernwalls exposed to direct sunlight(depending on unit)

Large concreted areas with littlepermeable surface area creates thepotential ooding

No facilities for naturally

drying clothes

No use is made of predominantnatural breezes

Dark coloured exposed walls oneastern elevation

Hot water not provided from solar

Minimal cross ow ventilation, if any

Concreted areas and heavyconstruction walls exposed to direct

sunlight act as heat sinksNarrow sliding windows

Incorrect orientation; both buildingsorientated north-south


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The Structure

In this section you are giveninformation to help in the selectionof the best materials and design for

your roof, walls, oors and windowsto ensure the good work you startedin the previous section is continued.The information is aimed at ensuringyour home provides a comfortableenvironment with the minimum useof energy.

Design philosophyThere are three major schools ofthought regarding housing design fortropical living:

1. light construction, for both elevatedand ground level with maximumcross ow ventilation and minimal airconditioning, and

2. heavier type well insulated

construction designed for higheciency air conditioning use, and,

3. those in the middle, adopting themore air conditioned environment forbedrooms and open, well ventilatedfamily and entertainment areas.

All three options however still rely on theprinciple of requiring good orientationand shading to reduce the heat load from

the walls and windows. This is essentialin all cases but is particularly vital forthe air conditioned environment whereoperating costs can be severely increasedas a result of poor design.

Design relying on full air conditioning toprovide comfort is not environmentallyfriendly and this decision has thefollowing disadvantages

Occupants of these types ofresidences will experience ongoingproblems in becoming acclimatised toour weather conditions.

The cost of power will increaseconsiderably as energy sourcesbecome more expensive andmeasures are put into place toreduce greenhouse emissions


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The RoofA roof pitch of around 12 will allowfor maximum eciency of your PVpanels and SHW unit for the Darwin and

Palmerston areas.With or without appropriate shadingof walls and correct orientation of yourhouse the roof is one of the majorsources of heat gain. A number of optionscan be adopted to reduce the eect ofthis major heat load.

Colour of roof

The colour of your roof is very important.Generally, the darker the roof the moreheat is absorbed or conversely, the lighterthe roof the more heat is reected. Thedeterioration of the reective propertiesof standard corrugated roof sheeting overa few years can have a noticeable eecton the heat absorption of this material.

Some roof paints that can be applied

to the roof, claim very high levels ofreectivity but generally the adoption ofa very light coloured or even unpaintednatural galvanised nish will provide

good levels of reectivity particularlywhilst the roof is relatively new.

Avoid a dark roof. They may look good,stylish, or modern but extra insulationand/or ventilation will be required just to

get rid of the extra heat being absorbedinto the structure. Better reectivity isnow achievable even with dark coloursbut they are not as good as the lightcolours and therefore require otheradditional work to overcome the extraheat load.

Ventilation of roof space

Ventilation of your roof space will ensureyour home remains cooler. This can be inthe form of roof vents, vents in the eavesand gables or some form of ridge venting.

The most common forms of roof ventsare whirlybirds with up to three beingrequired for an average household.One solar powered roof vent willprovide considerably more ventilation

(manufacturers claim twenty times onewhirly) for a similar overall cost and onlyrequires one roof penetration.

Using ventilation to cool the roof space


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Using ventilation to cool the roof spaceIf the room is not to be air conditionedthen the installation of insulation is notconsidered necessary and additional

ventilation to the ceiling space can beprovided in non-air conditioned spacesby inserting ceiling vents which will allowthe air trapped beneath the ceiling to bedrawn into the ceiling space and then outthrough a roof vent or whirly. This air,although warmer than the lower air in theroom is generally cooler than outside andcertainly cooler than the air it displaces inthe ceiling space.

It is important when consideringventilation of the ceiling space thatyou are aware of the problems thatcan occur as a result of condensation ifthe air conditioning is set at too low atemperature. This is particularly importantduring times of high humidity and it

may be necessary to have the insulationinstalled in plastic sheaths to act asa vapour barrier or have an eective

full vapour barrier installed above theinsulation to prevent the contact ofwarm moist air from outside directlywith the insulation.

Cathedral type ceilings should beavoided unless specially treated. Theyappear to be very tropical and coolhowever this is only the case whenproperly ventilated at a high level orair conditioned. Eective insulation ofcathedral ceilings is dicult and the lackof air gap in the ceiling means that it isharder to successfully ventilate that spaceand remove the hot air. In addition, thelarger volume of air, if the area is to beair conditioned, will result in signicantlyincreased cooling costs.

Airow available to keepareas with cathedral typeceilings cool

Care needs to be taken toensure that any ceiling fans

are not just circulating thewarm air trapped against theceiling. They become moreeective in providing coolingif installed on droppers,lowering them so that theirresulting airow can be felt.

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Colour of walls/cladding

Any walls exposed to sunlight needto be a light colour to reduce the heatabsorption. Insulating paints can also

reduce heat absorption.A preliminary investigation carried outon eight similar, identically orientatedtransportable accommodation units

at a remote location in the Top End ofthe NT clearly showed that the darkercoloured units on average (green versus

beige) consumed more energy forair conditioning (on average 60% moreeven when excluding Unit 1 from thecalculation) than the lighter coloured units.

Comparative Energy Use in Light and Dark Clad Transportable Dwellings

0

2000

4000

6000

8000

10000

12000

0 1 2 3 4 5 6 7 8

Unit Number

kWhh(9months)

Green

Green

GreenGreen

Beige

Beige

Beige

Beige


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False Walls

The painting of a wall in a light colour,a reective insulating paint or theprovision of a false wall will provide a

signicant reduction in the amount ofheat transmitted through the wall intoyour home.

The false wall is a simple way to provideshading to even an existing wall. It canbe made of corrugated iron with anair gap to eectively provide a degreeof insulation to the walls as well asreecting a lot of heat. Timber battens,

40-50mm thick, need to be installedvertically to aid ventilation of the spacebehind the false wall. The use of wooden

battens (non-heat conducting material)ensures a heat bridge is not formedbetween the sheeting and the wall.

Installing the sheeting with thecorrugations vertically reduces thelikelihood of dust and dirt collectingon the surface and aids the aircirculation process.

Diagrammatic representationof a false wall showing theeect of the induced airow


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Glass Types

The type of glass selected considerablychanges the amount of heat that entersa room.

A report6comparing the performanceof various glass types reached theconclusion that it could be concludedthat in sub tropical and tropical climatessingle glazing incorporating a tinted orreective glass with a low-E coating tothe inside surface of the glass would be asuitable method of improving the energyperformance and comfort within homes.

Recommendations for glazing based onthe study are:

For existing homes use a reective lmwith a low-E coating applied to theinside surface of the existing glazing

For new homes use a laminated solarcontrol glass with a low-E coatingapplied to the inside surface of thelaminated composition.

This ought to optimise the overall cost ofthe glazing system.

See Appendix 1.3 for comparative graphs

6 Jacob, Dr Leon The performance of various glass types Rockhampton Research House forDepartment of Public Works March 2008

Windows

Nonshaded, untreated glass windowsare a high heat source for your home.

The heat load through windows can be

reduced by

shading the glass

selection of glass with specialproperties,

the installation of heavy drapes/curtains or

a combination of these.

Extend your window openings as close aspossible to the ceiling level to encourage

the venting of hot air which may collectagainst the ceiling.

Reective backed curtains reduce some

of the heat entering a room. However,once the heat is through the glass andinto the room behind the drapes thensome or all of this heat will circulate intothe room. The drapes also block out anybreeze that can provide cooling.

Considerable heat can be transmittedinto the room if the windows havemetal frames. They conduct heat very

well and will radiate heat into the roomeven after sunset.

The simple solution is to shadeall windows in the first place


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Sliding door

Sliding window

Hopper Window

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The Low E glass (ie low emissivity) isa type of insulated glass that increasesthe energy eciency of windows byreducing the transfer of heat. The uniqueproperties of Low E coatings allow

the glass to retain very high daylighttransmission and act as a barrier to theabsorbed heat in the glass, reecting itoutside for better solar control.

Using glass which is only tinted will notachieve the same level of benet. Thegraphs show there was little dierencein the results achieved between usingthe clear glass and tinted glass. No

appreciable temperature dierenceoccurred between outside air temperatureand the room temperature when thewindow was tted with tinted glass.

Types of WindowsThere are ve main types of windows.

1. Sliding

2. Hopper

3. Casement

4. French and folding doors and

5. Louvres

Careful thought should go into choosingyour window type as their eect on yourinternal environment is important and thecost of changing style at a later date is

expensive.

Sliding style windows and sliding doorsrestrict approximately 50% of the airowcompared to a full opening

Hopper style windows also imposesignicant restrictions to airow for agiven sized opening

TIPAvoid sliding and

hopper type windows


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Casement Windows

Side hung casement windows openedtowards the direction of the cooling breezehelp direct the airow into the house thatmight otherwise go past the opening.

Casement windows are the best forcatching breezes, but like the foldingdoors they suer from security

problems when in the opened position.

Bi-fold Door

Bi-fold doors can be installed tomaximise ventilation and access toentertainment areas.

Louvre Windows

Unlike other windows, louvres can beopened on an angle when it is raining andallow breezes to enter whilst restrictingthe rain.

Louvres can be tted with relativelyunobtrusive bars that provide security foropen louvres but do not restrict airow.

Louvres can achieve the levels of sealingfor air-conditioned areas as required bythe Building Code of Australia (BCA) forresidential windows.

French doors, folding doors, casement windows, and louvres on the other hand havemuch larger equivalent openable areas.

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FlyscreensFlyscreens help control insects but dorestrict the airow.They need to bekept clean as dirty yscreens can

signicantly restrict airow regardlessof the window type.

Research7revealed that the drop inwind speed because of yscreens canbe signicant, in the order of 30+%,depending on ywire type and threaddensity. Dirty wire can also cause drops inwind speed through the yscreen in theorder of a further 10%. The retractable

yscreen allows for maximum ventilationwhen insects etc are not present.

Window FramesThe type of materials used in frameconstruction can seriously change theamount of heat transmitted through the

frame into the room, particularly if theframe is exposed to external heat, eitherdirectly from the sun or radiated fromunlined eaves and verandahs or concreteareas. Ensure that if using metal windowframes they do not have a thermalbridge eect. This will prevent externalheat being transmitted into the roomthrough the frame.

7 BEDP Environment Design Guide Tec 2, May 2007 page 9 - Natural ventilation in passive designby Richard Aynsley

8 Mabel Measurement of Darwin Houses Sept 2006 - Dr M Luther, Mobile Architecture and BuiltEnvironment Laboratory (MABEL) School of Architecture and Building, Deakin University, Victoria

This thermal image clearly shows the heat beingtransmitted through the metal frame and glass.8

The simple solution is to shadeall windows in the first place

Whilst the temperature of the wall (in this case a concrete block wall) is 28-30C, thetemperature of the glass and window frame is in excess of 40C. The upper section ofthe window may be shaded by the eaves.


28/48

Design of eavesand verandahsHaving a verandah particularly onthe northern side provides a method

of shading any exposed walls. Largeopenings and/or banks of louvres allowthe cooler air from under the verandah tobe utilised in keeping your home cool. Itis however important to ensure the eavesor sots (sheeted area under the raftersor bottom section of trusses) are linedpreferably with a reective material ttedto reduce the possibility of radiated heatreaching the walls or windows.

The positioning of pot plants/herb andspice gardens/small vegetable gardensor ponds along the verandah providesadditional cooling as the plants andwater act similarly to the cool pool. Theverandah has the additional advantageof allowing the windows to be left fullyopen in all conditions apart from thestrongest driving rain.

The cool pool is a method adoptedin many houses in the Middle East toprovide cooling by passing the in-comingair over the water. Some modern unitsin the suburb of Parap in Darwin have

adopted this ancient but simple methodto aid cooling.

FloorsThe eect of the oor on your homeand therefore its treatment is completelydependant on whether you have anelevated or ground level house.

Elevated housesIn the case of an elevated house theoor can be a source of heat duringthe day, particularly if heat is reectedfrom concrete under the house on tothe underside of the oor. Plantingvegetation or hanging awnings can keepthe sun o concrete or paved areas.At night the oor will generally follow

the ambient temperature and thereforeprovide some cooling.

26

This wide verandah providesshading to the walls, allows

doors/windows to be left openeven in driving rain and the linedsot protects the walls fromradiant heat as well as providinga pleasant outdoor dining andentertaining area


29/4827

A signicant issue to consider iswhether the area above the oor is tobe air-conditioned. If so, then the oorcan allow unwanted heat into the area inan elevated home, if precautions are not

taken. Carpet will provide some form ofinsulation and sound proong howevercare needs to be taken to ensure thatcondensation does not occur as thiscan cause premature deteriorationof the carpet.

The installation of compressed brecement (CFC) sheeting or equivalent oreven a polystyrene insulation, will reduce

the transfer of heat and sound throughthe oor.

Ground level housesIn the case of a ground level house theoor is certainly the coolest elementin the house during the day and even

the night with the temperature rarelyexceeding 30C. The temperaturewill remain equivalent to the groundtemperature and will change only veryslowly. Although the oor may be coolerthan the ambient temperature duringthe day it will certainly not cool downovernight and may be hotter than ambienttemperature during this time. Whencarpeted, the oor acts similarly to

an elevated house by following theambient temperature.


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Outside

This section deals with outdoorliving areas such as the garden,the swimming pool and hard surfaces

and how they aect your ongoingcosts and the environment. Carefulthought and simple planning can makethe outside of your house so muchmore ecient!

Location ofair conditioning units

Ensure the external components of yourair conditioning units are not installedon the northern or western sides of yourhome. If they must be installed in thislocation (for example to reduce the lengthof refrigerant piping) then ensure theyare in well ventilated and shaded areas- such as high up in the protection ofthe eaves. Some structures are designed

and installed to hide the units from viewbut care must be taken to ensure thatthey do not actually reduce the rate ofair ow around the unit thereby reducing

its eciency and its life because of theneed for it to work longer cycles trying toremove the same amounts of heat.

The unit is required to get rid of the heattaken from inside the house; if it is in ahot position then it makes it harder forthis to occur. A cooler well ventilatedposition helps it do its job. Sadly, the airconditioning industry has not listed thisrequirement in its recommended practisesand the numbers of units exposed todirect sunlight for large portions of

the day are testament to this lack offorethought and training.

If you are considering using a multi-headtype split air conditioner then ensure thatthe bedrooms and living areas are notcombined as their operating requirements(time of use) generally do not coincide.The result of the compressor unit havingto operate for much longer periods than

would be the case in a better balancedsystem is increased electricity costs andthe unit wearing out more quickly.

Note where the airconditioner compressoris planned to be installed.

This position is exposedto the afternoon sun andwill result in the unitperforming less eciently.

28


31/4829

WaterWe build huge dams, pipe the waterenormous distances, purify it all to apotable standard, use it once, put it

into another enormous reticulationsystem, spend huge sums on cleaning itagain, then throw it into a river so thatsomebody else can drink it downstream -then we wonder why we are shortof water.

We put all our black and grey waste waterinto the sewer -then import loads offertilisers to improve the fertility ofour gardens.

We build another reticulated system tocarry away the free rain that falls on ourroofs -without even using it.

The above quote is from Derek FWrigley.9Although referring to thesituation down south his commentsalso apply to Darwin (with the exceptionthat our waste is only partially treated

before being dumped into our harbour).

The average person in Darwin/Palmerstonuses almost twice as much water as theircounterparts in southern cities. A lot ofthis water (65%) is used unnecessarily inour gardens (2). We use approximately470 litres per person per day. This water

costs us over $2 million per year tocollect, pump and treat and this moneycould be better used elsewhere instead

of providing water to over-water ourgardens and wash down our driveways.

The following recommendations can bemore easily and cheaply incorporated intoa new house design than trying to installthem in an existing property at a laterdate. Some simple forward planning canmake the task so much easier.

9 Derek F Wrigley Climate change needs housing change published by the Nature and Society forum


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This shady nature strip was onlywatered for its rst 2 years whilstit was being established

30

Future use of rainand grey waterMake sure that if gutters are installed thefuture installation of a tank is simplied

by ensuring gutters are correctly slopedand the number of downpipes is limited.

Have the necessary planning done andttings installed during the constructionphase to allow you to re-use yourgrey water either now or in the future.Fittings can be installed that will allowyou to connect to them at a later date.Remember that you will most probably

have concrete adjacent to your houseso the pipes need to be installed beforethe concrete is laid. This could saveconsiderable cost and eort if you decideto or are required to make use of yourgrey water in the future.

Your gardenLimit the amount of your garden devoted

to lawn. Lawns are notorious water usersand unless mown with a hand mower useenergy in the continual ongoing mowingrequirements. The careful selection of theright lawn for your conditions can alsoresult in the need to water less.

Consider low growing ground cover asan alternative to lawn. Synthetic turf canalso provide a year round maintenance

free area for high use areas whilst stillbeing permeable to rain. Synthetic turf

does however have the disadvantage thatit can retain heat in sunny areas, is costlyand does not support any living things.

Plant water ecient plants (notnecessarily but preferably native)

to ensure your water use is minimised.Some plants only require water untilthey are established and can then staygreen and shady all year round withoutany watering.

Information about water-wise plantsis available in the PowerWater booklet10from the Top End Native Plant Society,www.topendnativeplants.org.au

or Greening Australia NT,www.greeningaustralia.org.au

Selection of the right plants and carefulplanning of your garden can result insignicant energy savings for your home.

Plant lower clumping type trees andshrubs nearer your home, as theyprovide a cool environment and can

develop their own micro climate systemsgenerating their own breezes. Leaves andpalm fronds can be seen moving evenwhen there is no noticeable breeze in suchenvironments. Do not plant immediatelyin front of windows and openings as youmay restrict prevailing breezes.

Use taller/larger trees to shade your eastand west walls from direct sun, be careful

when planting tall trees on your northernside as they may eventually shade solarpanels installed on the roof.

10 PowerWater Corporation and Nursery and GardenIndustry NT How to create a Water Wise Garden inthe Top End


33/483131

Garden reticulationsystemsPlan your garden reticulation system witha number of zones and place plants of

similar watering regimes together. Thiswill enable you to provide the amountof water necessary for those plants andthereby limit any wastage throughover-watering.

Concreted areasLimit the areas to be concreted or paved.Concrete causes three main problems,

1. It can reect heat onto the walls andwindows of your home.

2. It acts as a heat sink releasing heatinto the surrounds long after the sunhas gone down. Breezes that pass overheat sinks can be very hot compared tobreezes that come from shaded areas.

3. It reduces the amount of rain that

soaks into the soil and tends to directthe water to waste very quicklythereby overloading the stormwatersystems.

Light coloured concrete can reect alot of heat onto your house whilst darkcoloured paving or asphalt can act as aheat sink, radiating heat into adjacentmaterials and zones long after dark.

Consider the use of ground cover such aswood chips, permeable paving and lightcoloured pebbles or crushed rock.

Swimming pools and spasPlan for the future installation of a poolor spa when designing your house.Important considerations are size andquantity of water, location, fencing and

surrounding surfaces and vegetation.

What size?

The more water you need to ll your poolthe more money you will be spendingon power and chemicals, not to mentioncleaning! Think about the size and depth

of your spa, plunge pool or larger pool.The larger the surface area the morewater evaporation you will experienceand the more top up water you willneed. Sun and wind can lead to very highevaporation levels in the Top End. Deeperwater will stay colder than shallow pools.

To help plan the size of the spa or poolthink about how many people will be in

the water at once and what activitiesthey will be doing. Remember, its like ahouse, the bigger it is the more work it isto keep clean!

Where to place my spa or pool?

Pools require safety fences so plan theaccess points and fences to t in withthe house and garden features. If your

water is in shade it will remain colderand evaporate less than if in a sunny andwindy position.

Surrounds

When designing the area around the pool,avoid dark coloured surfaces that becometoo hot to walk on if they are in the sun.Think about owers, buds, seeds, leavesand palm fronds dropping into the pool

when selecting vegetation. Avoid ne leafplants as these leaves tend to drop tothe bottom rather than oating into yourskimmer box.

If you choose a salt water pool, avoidsensitive plants that cannot toleratesplashes of salt water.

TIPInstall a Viron pump and a pool coverand you are well on your way to cheaper

swimming


34/4832

Once you have considered the aboveand have decided to proceed, then thefollowing suggestions are recommendedto minimise both your ongoing costs andyour further impact on the environment.

1. Ensure the pump motor is a higheciency one to enable you to achievepower savings from the outset. Oftenpools are provided with inecientmotors and although cheaper initially,over a ve year period will cost youapproximately $2,000 more to run(Appendix 4.1).A pump can generatemore than 7 tonnes of greenhouseemissions based on 5 hours per day

operation during that period. Haveyour pool provider do an economiccomparison over a ve year period(including initial costs) of the motorthey propose compared to installing amore ecient unit.

The Viron pump, which makes use oftechnology developed in the NT, cansave approximately 70% in energyconsumption and is signicantly quieterthan other pumps. This enables youto install the unit closer to the houseand possibly reduce pumping distancesthereby providing further savings.Based on the 5 hours operationsuggested above, the Viron pump willsave you approximately $290 per year(Appendix 4.2)and the environment1 tonne of greenhouse gas emissions.That equates to more than $1,000 andnearly 6 tonnes of emissions over the5 year comparison period!

For more information on the Vironpump visit www.coolmob.org.

2. Limit the width of your pool to 5 metresand have a fairly regular shape whichwill make the selection of a pool covereasier and most probably cheaper.

Pool covers are recommended to

reduce the amount of top up waterneeded, and time operating the lterand the chlorinator. In turn, this willsave energy costs and pollution, and/or reduce the amount of chemicalsneeded to maintain water quality.

The pool cover for an average sizepool will pay for itself in approximatelythree years (Appendix 4.3)as wellas signicantly reducing the carbonfootprint of your swimming pool (morethan 1 tonne of greenhouse emissionsover that period) and saving you a lotof work in keeping the pool clean.

3. Do not install an automatic topup system as if they malfunctionconsiderable water can go to wastewithout you being aware. It is betterif you do your own topping-up as

required and measure the amountsof water used by reading your metersbefore and after relling. This helpsto clearly show the benet of having apool cover.

4. Use at least 50mm piping betweenyour pool and pump and keep it simple.The inlet and outlet pipe diameters,the length of piping, the use of elbowsand complications in the run, typeand quantity of jets all aect the backpressure and therefore operating costsof the system.

Thousands of litres of water per yearare saved by using a pool cover and theyalso reduce the amount of dirt/leaves etcgetting into your pool


35/483333

Inside

In this section, information is given onthe importance of the type of paintsand materials which will provide a

healthy environment for your familyas well as the importance of selectingthe right appliances. Appliances, onceinstalled will have a long-term eecton your ongoing running costs andconsequently inuence the eectyour life style has on the environment.Ensure the builder provides the rightappliances and ttings for you to giveyou a good start.

Hot waterThe selection of the hot water system foryour home is a decision that will have asignicant impact on your ongoing costs.A higher up front cost will provide savingsin the long run if you choose a solar

hot water system instead of the initiallycheaper electric or gas unit.

The actual annual cost to operate anelectric storage heater is dicult toascertain because the cost dependsso much on the usage habits of theindividuals involved. Power suppliersestimate that for an average family of4 it is in the range of $500 to $600 per

year. This will equate to more the $7,500over 10 years and more than 19 tonnesof greenhouse gases. (Appendix 5.1).

If you are restricted from putting a solarhot water unit (SHW) tank on the roofof your home then do not allow it todeter you from proceeding with the solaroption. Installing the tank at groundlevel with a recirculating pump movingthe water from the tank up to the solarpanels installed on the roof is a much

better option than using an electric orgas heater. The amount of power usedby a recirculating type pump is minimal

and would have negligible eect on theabove calculation.

When installing the unit on your roofhave it located it in a good position forsolar collection but avoid the middleof the area as this will inhibit theinstallation of PV panels at a later date.So often, the SHW unit, supplied witha new house during construction is the

rst panel on the roof and generally takesa central position thereby restrictingfuture options.

Consideration should also be given whenlocating your SHW unit that it is nearthe area which uses small quantities ofhot water more frequently - for examplethe kitchen. By doing this you reduce theamount of water wasted whilst waiting

for the water to come through the tap.

TIPPosition your SHW unit to allowinstallation of PV panels at a later date.


36/4834

PlumbingEnsure all plumbing ttings are 4 star(minimum) WELS (Water EciencyLabelling) and all taps are tted with

aerators. A 4 star toilet cistern will useapproximately 50% less water than anunrated unit. Your plumbing xtures willlast a long time so ensure you have thebest standard of water eciency.

You can save money on plumbing bychoosing a plan that groups wet areaslike kitchens, laundry and bathroom closetogether. The modern trend towardsmultiple bathrooms makes this dicult toachieve. The wastage and increased costscaused by the spreading services overa greater area, plus the extra ongoingcosts and cleaning are good reasons togive serious consideration to how manybathrooms are necessary for your home

AppliancesWhen negotiating xtures and ttingsfor your home, ensure you are goingto be provided with appliances thathave high energy star ratings. Buyingenergy ecient appliances can save youmoney on your bills and reduce yourenvironmental impact without making adierence to your lifestyle.

The actual appliance model and its starrating should be specied by the builder/developer and its important whenselecting the units that the cost

of operating the unit is considered. Insome cases some units can cost as muchto run over a 5 year period as they do topurchase, so it is important to do yourhomework.

To make a quick comparison ofappliances, the number of kilowatt hours(kWh) shown on the star rating label cansimply be called dollars based on 20centsper kWh over a 5 year period.

Ceiling fansCeiling fans are an essential part of livingin the tropics and are necessary whether

the home is air conditioned or not. Ifyour home has air conditioning, operatingyour fans (ceiling or free standing) willenable you to operate your airconditionerat a higher temperature setting and stillachieve comfortable conditions. This willalso save you power.

It is important that ceiling fans are not settoo high in areas with high ceilings as this

severely reduces the eectiveness of thefans. Fans set too high will distribute thehot air trapped against the ceiling aroundthe room.

Keeping fans clean is important; a dirtyfan uses more power because of theextra drag on the blades. For this reason,the stainless steel blade units arepreferable as they tend not to deteriorate

as quickly as painted blades. Paintedblades tend to collect dust when the paintstarts deteriorating, especially on theleading edges.

TIP

Having windows that open to ventilate bathrooms

and laundries is cheaper and quieter than relyingon an exhaust fan. Your rooms will have a light airy feel

and youll save on electricity.


37/483535

Fans tted with a variable speed controland o switch are more convenientthan those with a 3 speed controller.The variable speed control allows muchbetter control and the simpler turning o

action may encourage the turning o offans when leaving a room. Remember toalways switch fans o when a room isnot in use, as this will save energy useand costs.

Air conditioningAir conditioning is often used to achievecomfortable sleeping conditions by

lowering temperatures and humidity.The number of operating hours requiredfor air conditioning to achieve thermalcomfort can be substantially reduced(or eliminated) by careful design of newhomes, alterations and additions.

PaintsRegular paints give o low level

toxic fumes that can cause breathingirritations and headaches.

Most paints contain some toxic chemicalswhich can be harmful, most commonlyvolatile organic compounds (VOCs).These are the toxic fumes emitted frommost synthetic-based paints and makeup the new paint smell that many peoplend unpleasant. VOCs can be harmful

to people and the environment in themanufacturing process and during andafter application.

VOCs can continue to seep out in smallamounts for years after painting and canlead to many health problems. It takesyears for them to completely disappearand often, by then its time to repaint.The smell is not a major problem in new

house construction as most of the smellhas dissipated by the time you move into

your completed house. However, it maybe more of an issue when renovating an

occupied home.Green paints are dened by their lackor low level of VOCs. Green paintscan be either environmentally friendlynatural paints or environmentally friendlysynthetic paints. On the whole naturalpaints are a little more environmentallyfriendly in their manufacture and disposalthan synthetic paints. However synthetic

paints are generally a little less expensive,a little more durable, and come in a widerrange of colours. Both are non-toxic andhave zero or very low VOC level.

It is therefore important when planninga new home or renovations thatconsideration be given to the type ofpaint used particularly if members ofyour family have respiratory symptoms,

allergies, chemical sensitivities andparticularly for pregnant women andyoung children.

These paints generally cost more,however the environmental gains shouldbe taken into account when doing theevaluation. Consider the application rates,number of coats required, durability etcas well as the base cost of the material

when comparing costs.

TIPIf you plan on installing and using air

conditioning make sure the areas are wellinsulated and sealed to ensure ecient use

of the air conditioning.


38/4836

KitchensA well designed, eciently equipped,functional kitchen can add real valueto your home.

Layout of kitchens

A good kitchen gives you room to movebut is compact enough to allow easyreach between dierent activities, likepreparing food, cooking and rinsing. It is agood idea to leave generous bench spacebetween the sink and the hotplates asthis tends to be the most useful space forfood preparation.

Locate dishwashers close to sinks toallow easy loading: this also concentratesyour plumbing requirements in one place

Position refrigerators and freezersaway from stoves/ovens and externalwalls exposed to direct sunlight.Ensure refrigerators and freezers arewell ventilated. The eciency of these

appliances depends on their abilityto remove heat and if ventilation isrestricted then their eciency decreases.If the unit is enclosed then provideadditional ventilation into the ceilingspace. Ensure sucient space is allowedaround the unit in accordance with themanufacturers recommendation.

Multi-bin sorters under/near kitchensinks are a great idea to sort your rubbishfor recycling straight away.

Remember, a lot of heat is generated inthe kitchen and a lot of time is spent in

this room so it is important to ensure it iswell ventilated and has as much naturallight as possible.

Kitchen equipment

The selection of the equipment thatis most ecient, cheapest to run andbest for the environment at the time ofequipping your home may result in an

increase in the overall cost of your kitchenbut you will certainly reap the benetsover the life of the appliance. To changea less ecient appliance later couldmean a signicant cost. Carefully selectwhat is best suited for you, not what isjust generally supplied by the builder. Tochange a less ecient appliance latercould cost you dearly.

Choosing the right sizefor your needsis also very important. A big 4 starrefrigerator uses more energy than asmaller 4 star refrigerator.

You can choose either a single unitsuch as a gas or electric stove, or acombination of gas and electric separatehot plates and oven.

If for example, an appliance uses 400kWh per year to run, this equates to $400 to runfor 5 years. The price of power is already above the 20 cent mark per unit and willcertainly increase over the nominal 5 years period of the calculation but this does workas a quick way of comparing appliances.

Any savings in operating costs is also a saving for the environment.

TIP


39/4837

Hotplates

Gas hotplates are generally cheaperto use, respond rapidly, are easy toadjust, provide good temperaturecontrol and importantly produce less

greenhouse emissions.

Of the electric options the followingchart11compares the various types

Type of electrichotplates

Efciency (%)

Coil 55 - 65

Solid 50 - 55

Ceramic - Standard 55 - 60Ceramic - Halogen 45 - 50

Ceramic - Induction 80 - 85

Ceramic cooktops have the elementsconcealed under a at glass surfaceproviding a stylish appearance, are easierto clean than coil and solid hotplates

however they are less ecient, have aslower response time and are generallymore expensive.

Ovens

For your new oven, look for energyecient fan-forced models with tripleglazing and a high standard of insulation.Fan-forced ovens heat more quickly than

conventional ovens, can cook food atlower temperatures, and use up to 35%less energy than conventional ovens.

Gas ovens, although they will heatto a given temperature much fasterthan an electric oven require ventilationand lose considerably more heat thanelectric units, thus heating up yourkitchen and home.

Microwave ovens

Microwave ovens can be extremelyenergy ecient as a result of the shortcooking times involved. The energy usedis generally used to heat the food only,with little wasted in heating cookingutensils or the oven itself. The resultantshorter cooking times means less energy

consumption than conventional ovens.B-B-Q

The nal option to consider is theB-B-Q. Incorporate an external spacefor one in the design of your homeand if installing gas then have thereticulation extended to allow the unitto be connected. This avoids the need torell smaller gas bottles. A B-B-Que has

the obvious advantage of ensuring thatcooking does not heat up the kitchen.11 Oce of Energy Government of Western Australia

http://www.yourhome.gov.au/technical/fs61.html


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Lighting

There are a number of basic rules toconsider when choosing lighting.

Dont over-light your home. Avoid

the tendency to provide unnecessarilyhigh levels of lighting, especially whenusing downlights

Use only uorescent, compactuorescent or LED lamps

Make sure the number of ttingsturned on by one switch is limitedso that you have much better controlover how many lights you are turning

on at any one time. More lights thanyou need on the one switch can bevery wasteful

Home designers/decorators ofteninstall more ttings than necessaryand could achieve adequate lightinglevels and gain the same eect byusing other types of ttings and lamps.

Remember that low voltage does notmean low energy so when comparingdierent types of lamps comparewattages. A 12 volt 50 watt lamp(excluding transformer) uses the samepower as a 240 volt 50 watt lamp.Incandescent and halogen lamps onlyconvert a small amount of their energyinto light; the majority is converted intoheat, just what we dont want in the

tropics. These lamps can become hotand uncomfortable to sit under.

Power Points

Avoid the tendency to install powerpoints where they wont be seen behindappliances, as you want to be able toreach them easily to turn the units o to

reduce stand-by power. This particularlyapplies to home entertainment equipmentand, in the kitchen, the microwave.


41/483939

Why This Book Was Written

In his paper Climate change needshousing change Derek F Wrigleyhighlights the need to be critical

about contemporary housingdesign practices.

there is insucient constructivecriticism about architecture these daysand consequently we never seem tolearn from our mistakes. The eectiveuse of natural resources is a criticalenvironmental science and should be openfor healthy, informative public debate, sohopefully these comments can be useful.

Otherwise, how will we ever learn andimprove? The results of no criticismcan be seen anywhere around thesuburbs of Australia and regrettably thehousing industry has shown itself to bea slow learner.

There is an urgent need for rational voices

to be raised in this debate. When arethe opinions of concerned house buyersever heard - where is their forum? It hasbeen too one-sided for too long, as thisbooklet reveals. If you have somethingto say about housing standards, let yourvoice be heard, otherwise the status quowill only continue.

This booklet includes drawings and

composite pictures of residences (somenew houses, just completed or not fullycompleted) that will have problems andhigh associated energy use for many years.

Some of the houses depicted wouldbe extremely expensive and whilethe owners may be in a position tocomfortably pay for the additional energythey use, it should be acknowledged that

the wasteful use of energy contributes tothe current detrimental impact of humanson our environment.

Dark coloured roof and walls

Lack of shading on northern

elevation

High heat load transfer throughwalls due to lack of shading

Limited window size

Lack of garden depth to provideshading

Complex roof structure for future

solar and water collection

Complex roof structure withnegligible space for solar collection

Large numbers of downpipesdrastically limiting your ability tocollect rain water

Air conditioner compressorsexposed to direct sunlight

Heavy construction (blockwork)exposed to sun


42/48

Dark coloured heat absorbing walls

Air conditioner compressors exposedto direct sun

Small and limited number of windows

Complex roof design

Complex roof structure with anumber of downpipes limitingwater collection

Large expanse of unshaded heavyconstruction exposed to directafternoon sun

Air conditioner compressors exposed

to direct sunVery limited cross-ow ventilation

No attempt or space to usevegetation to provide shading

40

The COOLmob

problem andsolutionThe photograph aboveillustrates a house whichis supposedly designed fora Mediterranean climate.For all the reasons listed inthe previous examples it is

unsuitable for the tropicalconditions in Darwin.

Housing being constructed today will be with us for around 30 years. The damage tothe environment caused as a result of poor design and construction (such as higherconsumption of energy and the associated demand on natural resources) keepsincreasing with time, with every unsuitable new house built. Moreover it does nothingto make home ownership more aordable for ordinary people.

We already have the knowledge and the tools to build housing which is suited toDarwins climate. We can make easy changes at a personal and community level now

to have a positive environmental impact in the future. These changes will also save usmoney without having to compromise living standards.


43/484141

Appendix

1.1 Household comparison system

The chart was based on the audits completed by COOLmob in Darwin 2002-04

1.2 Estimated expenditure on power over next 10 years

PerQuarter

2010 2011 2012 2013 2014 2015

$300 $1,200 $1,284 $1,374 $1,470 $1,573 $1,683

$1,100 $4,000 $4,280 $4,580 $4,900 $5,243 $5,610$1,600 $6,400 $6,848 $7,327 $7,840 $8,389 $8,976

2016 2017 2018 2019 2020 Total

$300 $1,801 $1,927 $2,062 $2,206 $2,361 $17,740

$1,100 $6,003 $6,423 $6,873 $7,354 $7,869 $59,134

$1,600 $9,605 $10,277 $10,996 $11,766 $12,590 $94,615

The base cost used in this calculation is assessed from households achieving 10, 5 and2 stars respectively on the COOLmob Energy rating system12.

12 The cost of energy has been increased at an annual rate of 7% to allow some inclusion for the expectedincrease in energy costs. This calculation however does not include any allowance for a carbon orequivalent tax being imposed which would signicantly increase the costs calculated.

Coolmob Energy rating system

0.00

10.00

20.00

30.00

40.00

50.00

60.00

70.00

80.00

90.00

1 5 9 13 17 21 25 29 33 37 41 45 49 53 57 61 65 69 73 77 81 85 89 93 97 101 105 109

Number of residences

kgCO2perpe

rsonperday

10 Stars = 6.1

0 stars = 32

5 stars = 19.1

Extreme results not included in rating


44/4842

1.3 Performances of dierent glass types

Only very minor benet is gained by using tinted glass


45/484343

The benet of the clear glass with Low E lm is clearly shown

However the laminate glass with Low E dierential achieved the best results


46/4844

4 Swimming Pools4.1 Standard Pump

Power used and greenhouse gases produced by a 1kW pool pump over a 5 year period

Pumprating

kW

Runhours

per day

kWhper week

kWhper year

$ peryear

kg CO2per year

kg CO2over 5years

1 5 35 1820 400.4 1437.8 7,189

(7 tonnes)

2011 2012 2013 2014 2015 Total

$400 $428 $458 $490 $524 $2,300

4.2 Viron Pump

Power and greenhouse gases saved by using a Viron pool pump over a 5 year period13

2011 2012 2013 2014 2015 Total $over 5years

kg CO2over 5years

$290 $310 $332 $355 $380 $1,668 5,989

(6 tonnes)

13The cost of energy has been increased at an annual rate of 7% to allow some inclusion for the expectedincrease in energy costs. This calculation however does not include any allowance for a carbon orequivalent tax being imposed which would signicantly increase the costs calculated.


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4.3 Pool Covers

Based on using the pool cover for 3 months each year. Increase use of the coverincreases the savings.

Operating costs over 3 years Savings

Power See 4.1 above 2011to 2013 $1,286 kg CO2

Not ltering for 3 months per year $321 1,154

Chemicals $30 per month $1080 (1 tonne)

Reduced chemical requirements $270

Water 1.5kL per fortnight to top-up $42

No water loss for 3 months per year $11

Total $602

5 Solar Hot Water UnitsPower used and greenhouse gases produced by an electric hot water service overa 10 year period13

2011 2012 2013 2014 2015 kg CO2

$550 $589 $630 $674 $721 1,975per year

2016 2017 2018 2019 2020

$771 $825 $883 $945 $1,011

Total $7,599 19,750

(19 tonnes)


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The content of this publication does not necessarily represent the position of our sponsors.

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