Passive Design for ClimateSmart Housing
Design Principles for Housing in Queensland’s Climate Zones
An Introductory Guide
Passive design is a key feature of a sustainable house. This guide provides an overview of the passive design
principles and associated information that can improve household comfort, livability and savings in each of
Queensland’s four climate zones. It presents a summary of passive design concepts and benefits that can be used to
assist in designing a new house, or altering or purchasing an existing house.
Passive Design Principles for Energy Efficient Housing in Queensland
The sale and use of air-conditioners in Queensland has increased rapidly in the last few years due to a range of
factors, including housing being inappropriately designed for it is prevailing climate. To realise a more suitable and
sustainable housing design for our climate it is important to consider traditional housing styles. The classic
‘Queenslander’ can be considered to provide some useful insights for “ClimateSmart” housing, and many of its
design principles are behind the ‘re-found’ movement for today’s passively designed homes.
The ‘Queenslander’ House
The old “Queenslander” style house is generally regarded as a good example of a comfortably designed house
broadly adapted for Queensland’s climate. Although residents in the southern part of the state sometimes refer to
‘freezing’ in them in winter as they can often allowed cool night air to leak indoors (if they didn’t have an internal
fireplace) or occasionally being in an ‘oven’ during summer heat waves, the Queenslander was, for its time,
reasonably adapted to suit our climate on most days of the year. If bulk insulation had been available and included
as part of its construction, it would have basically addressed the majority of housing comfort needs in most of the
state, and for all seasons. Although it was built throughout Queensland, it is recognised that it does not perform as
well in climate Zones 3 – Hot Arid and 5 – Warm Temperate, where thermal mass has a more beneficial role than
the lightweight design of the Queenslander.
The design of the Queenslander originally came from India during the days of the Raj when English Victorians had
to adapt to its hot, tropical climate. There were often substantial roof overhangs (roof eaves), or awnings were over
every window with returns on the low-sun sides to block direct sunlight (window eaves). The sash windows could
be opened not only at sill level (sometimes at floor level), but also from the top of the high frame. With high
ceilings, this allowed fresh air to enter higher up and travel across the room before filtering through the fanlight
space above the door, and through to the window on the other side of the house – creating excellent crossventilation for cooling. A ceiling rose at the centre of each room expelled the hot air that was not blown out the
sides up into the roof space, which then travelled out of the roof’s ridge vents. The front door usually opened onto a
long hallway that ended at the rear door. Wrap-around verandas provided substantial shade and created a ‘transition
zone’ – that wonderful space where residents could enjoy the opportunity to find the coolest spot on a hot day (with
sections of timber lattice that filtered the harsh summer western afternoon light) or the warmest sunny spot during
winter.
The Evolution of Queensland’s Housing Stock
Over time, changing social attitudes rejected the historic form of the Queenslander. The possibility for more privacy
increased with higher average incomes and the verandas, or “sleep-outs”, were simply enclosed to accommodate
extra bedrooms. The transition zone was thereby absorbed, and with it, cross ventilation opportunities decreased.
Also, newer designs often did not extend the roof out to provide for the lost veranda shade cover for cooling. The
ceiling height dropped and the fanlights and the ceiling roses also disappeared. However, the windows were often
casement types that could still be positioned to catch some breeze, or louvres that could be opened to catch the full
breeze. Eventually though, these practical windows subsided as sliding aluminium windows came onto the market,
effectively halving the amount of potential cross-ventilation into the house. Homeowners may have gained more
privacy and saved on purchase costs, but they lost their home’s natural comfort and livability potential.
1
Since the Second World War, the majority of houses in Queensland have not been designed and built individually.
Instead, they have been supplied in bulk, located in sub-divisions cleared for suburban development. Little thought
has been given to providing good room-zoning opportunities, as houses were often built with the living room facing
the street regardless of their western sun orientation and local climatic conditions. More recently however,
developers and builders have started to realise some basic passive design principles, such as including a northfacing living room.
Fundamental Passive Design Principles
The above summary highlights the need for the incorporation of fundamental passive design principles to achieve
more comfortable houses that are also energy efficient i.e. cooler in summer and (in cooler parts of Queensland)
warmer in winter. The six passive design principles are (in order of priority):
1. orientation – generally, wherever possible, orientate the living area to the north for winter warmth in the cooler
parts of Queensland and away from the summer sun in north Queensland. Utility areas such as the garage,
storage rooms, entry and laundry should be positioned to the south-west to shield the house from the setting
sun.
2. ventilation – openings throughout the house allow summer breezes to provide cooling cross-ventilation.
3. shading – effectively shading walls and windows prevents heat transfer e.g. roof and window eaves.
4. insulation – insulate the roof space against heat and cold transfer, and insulate the walls where no overhangs
are provided.
5. thermal mass – build in thermal mass to absorb heat where it can be useful to re-radiate this heat at night (NB.
this principle applies mostly to Zones 3 – Hot Arid, and 5 – Warm Temperate where hot days can be followed
by cool nights).
6. materials – use energy-efficient materials appropriate for the climate zone to improve thermal performance e.g.
external walls, windows/glass/tinting and solar pergolas.
The application of these passive design principles for housing in Queensland’s climate are detailed further below.
1. Orientation
House orientation is the fundamental passive design principle as it significantly affects the house’s comfort and
energy performance. Consider how the plan interacts with the site, as good orientation maximises the benefits of
solar access, cooling breezes, summer shading and wind protection.
Where practical, it is recommended houses be orientated so their western side blocks out the heat from the low
summer sun, and their south-western side acts as a buffer against westerly winds. As a general rule, window area on
the north-facing wall should be 10-25 percent of the floor area of the room so that the room can gain suitable access
to winter sun.
In areas north of Rockhampton, the southern side of the house should normally be shaded, as this can provide some
liveable outdoor space in summer. However it should also be recognised that this space can occasionally get cool on
winter days, so design this space for flexible use. In Zone 1 – Tropical, the midday summer sun strikes the southern
face of the house, while midday winter sun is toward the north.
Establishing True (Solar) North, not Magnetic North
It should be noted that true (or ‘solar’) north significantly deviates from magnetic north throughout Queensland and
this should be taken into account when orientating a house. Maps and street directories can give this information, or
alternatively use a compass to determine magnetic north and then subtract true (solar) north by adding the magnetic
variation for your location using the following map:
Diagram: True (Solar) North as Degrees West of Magnetic North (Your Home)
The ideal orientation is between the range of 150W to 200E of true (solar) north (although 200W to 300E of true
north is acceptable). This allows appropriately sized eaves to admit sun in winter to heat the house and shade it from
the hot summer sun. Sun path diagrams for a range of Queensland’s major cities and regional centres have been
2
devised to provide assistance with specific house orientation issues and room zoning, and these can be downloaded
from the Smart Housing web site: www.housing.qld.gov.au/builders/smart_housing/sunpaths/orientation.htm
2. Ventilation
Throughout Queensland’s summer, the ultimate home comfort aim is to live in a house so well ventilated and
shaded that it would be like sitting under a large tree on a hot day where the breeze can pass unhindered. Such a
concept can be incorporated into a house through applying the design features presented below:
i. Openings
As windows and door openings receive breezes, the more flexible the opening the better its potential for ventilation.
Sliding windows are very inflexible, as they generally have two panes and only ever have potentially half of the
opening available to catch breezes. Casement windows and hinged doors can catch the breeze when positioned
correctly. For example, if the cool summer breeze is from the north-east then ensure the windows are hinged on the
western side of the outside frame (or the left side from inside the room). Louvers and awning windows can direct
the breeze down into the living space of a room. They need not all be glass, as timber louvers provide shade as well
as breeze (and remember to chose from plantation timbers).
ii. Cross ventilation
Once the breeze is inside the house it should be able to flow through to the other side as uninterrupted as possible.
Careful planning of rooms is required such as (wherever possible) two windows in each bedroom to provide better
cross ventilation. Attempt to locate doors adjacent to each other as this can also assist with cross ventilation. As air
moves upward when heated, adjustable fanlights or vents are recommended over internal door openings to remove
the hot air accumulating at ceiling level in summer. They also need to be able to be closed to reduce heat loss in
winter. Vents located in flat ceilings in the hallway and kitchen can provide an additional advantage, as long as the
roof is adequately ventilated. This allows the heat gathered at ceiling level to be expelled up into the roof space.
Ceiling vents in Zone 2 – Sub-tropical also need to be sealed in winter to keep the warmth in.
iii. Roof space and colour
An oven perched on top of a house is a reasonable analogy as to what happens inside a roof in summer. Insulation
acts as a barrier to prevent hot air from radiating down into the house’s habitable spaces. Reflective foil needs to
have a minimum 50 millimetre gap between the underside of the roof sheeting to function effectively. When fixed
to the underside of the rafters (excluding truss rafters) it will normally create a thermal flow for the rising hot air to
escape out through the roof’s ridge vents. The addition of bulk insulation can also slow down the movement of this
heat, but it can only repel a limited amount.
Effective roof ventilation can remove this heat build up through openings in the roof’s eaves and the placement of
ridge vents. Basically, air enters through vents provided in the eaves and heated air rises to the roof’s ridge where it
can be expelled through ridge vents. Eaves and soffits should be vented to allow cooler air into the roof space and
the vents are to be kept free of any blockages, such as ceiling insulation and foil. Ridge vents remove this heat, with
larger roofs requiring more than one vent. Houses that have insufficient eave overhangs and vents are not only
penalised by their lack of shaded protection to the walls, but the hot air in the roof space also stays longer, and
similarly if there are only ridge vents (as the hot air can not escape effectively).
The ridge can be vented in a number of ways. The first is a short gable at the ridge providing adequate weathering
protection and permanent ventilation. Whirlybirds are becoming a common roof feature, but a better choice is the
fixed-vent versions that do not have the maintenance/replacement requirements of moving parts. The clerestorey
design also offers an alternative for ridge venting. The openable venting area can be greatly increased, though the
opening should not be located towards the summer sun as that could allow unwanted solar gain. A solution to this
problem when using metal deck roofing is to simply provide a second skin of sheeting at the ridge, close enough to
the main roof to prevent rain entering yet sufficient to allow heated air inside to escape.
A light-coloured roof is also a good advantage. As a bitumen road readily absorbs heat because of its colour, a dark
roof does the same. A light-coloured roof can reflect unwanted heat before it even gets into the roof space. Whilst it
is incorrect to suggest that all roofs should be white, those with a light-coloured roof will reduce the heating
capacity of their home’s roof space, thereby potentially enhancing comfort levels and minimising energy demands.
3
iv. Cathedral ceilings
Cathedral ceilings are angled, with ceiling sheets fixed to the underside of rafters or scissor trusses. They are ideal
in hot climates if they are designed properly. Unwanted heat from the habitable areas rises away from the occupants
as it warms the air and accumulates at the highest point of the ceiling. If the warmed air is not allowed to escape it
will eventually fill the room, so it is essential to release the heat gathered at the ridge, either into a ventilated roof
space or directly outside through wall openings placed just below the highest part of the ceiling. Cathedral ceilings
often have little or no roof space which would normally assist to reduce heat flows between the roof and the ceiling,
so it is also important to provide good roof and ceiling insulation.
Proper landscaping, pools or water features and other external shading devices such as verandas, overhangs,
awnings and pergolas can also reduce the air temperature before it reaches the house.
3. Shading
Shading includes roof eaves (overhangs), window eaves (awnings), as well as significant vegetation, that may
reduce direct east and west sunlight penetration into wall(s). As most external wall systems have a low thermal
resistance, shading and/or insulation is required. Shading lowers the house’s heating capacity and can minimise the
need for air-conditioning.
As the seasons change, so too does the angle of the sun. In Zone 2 – Sub-Tropical, the winter sun passes lower in
the northern sky. The house has higher exposure to direct sunlight in the cooler time of the year, as the sun’s rays
can pass under the overhangs and/or awnings, and naturally warm the house. By adopting this design feature, the
house can achieve a better comfort level and reduce the need for mechanical heating.
In the northern parts of Queensland, the sun arcs almost directly over the house throughout the year – slightly to the
south in summer and slightly to the north in winter. Effective overhangs on the north and south of the house and
shielding from the rising and setting sun on the east and west will provide adequate shading to the house for most of
the year.
In addition, there are differences in the amount of shading. Extra measures are needed to reduce the amount of heat
absorbed on the eastern and western sides at sunrise and sunset. Opaque screens or shutters can act as remedies as
they can be fixed on the outside wall and adjusted to suit. A range of varieties are available and include traditional
and contemporary designs. Of particular interest is the adjustable shutter, a type often found in Italy, as it can also
be hinged within the individual leaves to provide an awning for further ventilation. Re-locating verandahs and
covered balconies to the east or west can also improve shading.
Screens, such as curtains inside the window, are not recommended to be used purely as shading devices as air
cannot circulate as freely inside as it can outside. The sun’s rays pass through glass as long-wave radiation and are
changed to short-wave radiation once inside. These rays cannot then pass back out through the glass. A typical
example of this is when you get into your car when it has been in the sun with all windows wound up. So, hot air
rises inside the house and is trapped in the room, particularly if there is a sliding window with no chance at all for
the heat to escape. Another way to further overcome the problem is to use plants as a screen, although this cannot
supplement a structural screen for the obvious reason that a plant screen may at be removed in the future.
Window awnings are recommended where there are little or no roof eaves. However, it is not sufficient to simply
attach an awning the exact width of the window as sunlight often hits the window obliquely and can heat a large
proportion of the glass. Awnings should be wide enough to shade the window during summer when the angle of the
sun is steep and hot, such as the afternoon.
4. Insulation
Houses need to be insulated from the heat in summer and, for those areas especially those in Zone 5 – Warm
Temperate, from the cold in winter. Insulation can assist to reduce the effects of these extreme temperatures as it
provides greater comfort levels. As the main sources of heat flow is through glass, roofs and walls, insulation can be
installed inside roofs and walls to better regulate this heat flow.
4
All insulating materials have an “R-value”, which is a unit of thermal resistance used for comparing insulating
values of different materials. The higher the value, the greater its insulation properties. R-value requirements for
roofs and walls may differ between climate zones. The final design should achieve an R-value at least equivalent to
the Building Code of Australia (BCA) requirement for the relevant climate zone. Installing more insulation than is
required by the BCA will provide additional benefits.
Add more on insulation from Your Home?
5. Thermal Mass
Dense materials like concrete, brick and other masonry, such as rammed earth, have "thermal mass" i.e. materials
that have ability to absorb and store heat during the hottest part of the day so that it can be released at night to create
internal warmth. Thermal mass can moderate internal household temperatures by averaging day/night (diurnal)
extremes. Thermal mass can be applied effectively by using:
 Tiled or concrete slab floors;
 Cavity masonry walls;
 Interior masonry walls; or
 Exterior masonry walls.
Concrete ‘slab-on-ground’ floors provide ‘thermal coupling’, allowing heat to be transferred from inside the house
to the ground below the house. As the temperature of the ground below the surface remains relatively constant
throughout the year, its capacity can be used to absorb heat on hot summer days and release heat on cold winter
nights. For effective heat transfer to occur, concrete slab-on-ground floors should not be covered with carpet as this
acts as an insulating layer. Heat conductive materials, such as tiles and vinyl floor coverings, do not interfere with
heat transfer to the ground.
Another means of providing thermal mass is ‘reverse block construction’. From the viewpoint of heat transfer,
reverse block construction is the opposite design of a conventional brick veneer wall. This technique uses
lightweight cladding (like steel sheeting, timber or fibre-cement) on the outside with massive construction materials
comprising the inside layer of the wall. An intermediate air space (which may contain bulk or reflective foil
insulation) isolates the internal massive wall from heat gain or loss to the external environment.
In cold temperate climates, massive construction is important for winter comfort. During clear winter days, ample
sunshine is available to warm the inside of a house (provided that a sufficient north-facing window area is
available). Even in Zone 5 – Warm Temperate areas of Queensland, winter temperatures usually rise to a
comfortable level in the daytime. The major problem of winter cold discomfort occurs with the on-set of evening
through to the early morning (i.e. when no solar energy is available). To keep a house warm at night there must be
enough thermal mass to store solar heat during the day so that it can be released at night. This technique can be
effective provided there is a sufficient north-facing window area and thermal mass, as well as adequate insulation in
roofs and walls, to slow the escape of heat.
In Zone 2 – Sub-tropical, thermal mass, solar heat entry (via good orientation) and insulation can work together to
provide winter comfort. However, there is little advantage in just having large north-facing windows to collect
sunshine if there is insufficient thermal mass to store solar heat when it is needed at night.
Thermal mass can cool a house in summer only in regions where summer night-time temperatures are sufficiently
lower than summer day-time temperatures (i.e. the diurnal temperature range). Night-time temperatures must be low
enough to remove all of the heat the thermal mass has gained throughout the day, and then be able to cool the wall
or floor so that it remains cooler than the internal air temperature for the following day. This process allows the
thermal mass to cool the room by absorbing heat from the air. A large diurnal temperature range in Zone 3 – Hot
Arid areas makes thermal mass an appropriate tool to achieve household comfort as it acts to even out the peaks and
troughs of the temperature differences. In Zone 5 – Warm Temperate, thermal mass can be used to maintain
comfortable conditions in summer and winter.
The diurnal temperature range in Zone 1 – Tropical is generally too small to allow this cooling effect with thermal
mass. The re-radiating property of thermal mass at night is a liability and an un-insulated thermal mass wall in
5
direct sun is likely to begin radiating heat into the house well before sun-set. If used, thermal mass should be
insulated and totally shaded to reduce the amount of heat it absorbs during the day. Insulation on the inside of the
wall will reduce the heat radiated into the house. Providing ventilation within and around thermal mass can help to
decrease heat gain and radiation.
Lightweight construction is a valid approach to achieve summer comfort in both Zone 1 – Tropical and Zone 2 –
Sub-tropical areas, as lightweight materials cool down quickly. They also offer a simple, low-cost solution to deal
with steep sloping sites, unstable soils, and sites inaccessible to transport heavy materials.
Another feature that can be used in lightweight construction is a ‘suspended floor’, which is simply a floor raised
above the ground and suspended. The main benefit of suspended floors is that the house may be elevated into less
interrupted breeze paths, however this significantly depends on the topology, surrounding vegetation, and proximity
of adjacent buildings. In domestic construction a suspended floor is usually associated with joist and bearer
construction (either steel or timber), but non slab-on-ground floors are also called “suspended” (it is actually more
usual to refer to the term “suspended” in conjunction with “concrete”; timber and steel-framed floors are usually
just called timber or steel-framed floors). Suspended concrete floors are occasionally used in houses.
It is recognised that slab-on-ground is the one piece of thermal mass that works well in the tropics. The ground a
house sits on is usually much cooler than the air circulating around it, effectively taking advantage of the thermal
mass of the soil beneath the house.
6. Materials
A range of energy-efficient materials can be used to assist thermal comfort and natural lighting, including:
i. External Walls
External walls are required to achieve minimum energy efficiency through its R-value (refer Section 4). The
required R-value for external walls can be achieved through a composite layering of materials. Some manufacturers
concertina the reflective foils to automatically provide for BCA requirements. The gap with the concertina is
essential to allow thermal resistance. A vertical air gap itself provides an R-value of 0.16, allowing the air to rise as
it is heated and be released at the top into the roof space, provided the roof insulation does not cover it. The vents in
the roof will remove the heat and promote the air in the cavity to rise as convection currents are established.
Aerated autoclaved concrete at 200 millimetres thick will give an R-value of 1.5. An additional render will provide
a further resistance to heat transfer. Concrete blocks with external foam insulation give an R-value of 1.5. Internal
brickwork (or concrete blocks) and a lightweight external skin, referred to as reverse brick veneer has the advantage
in cooler climates of providing an internal thermal mass to soak up the heat produced inside the house during the
day, to radiate back into the room at night.
Other alternative construction options are “rammed earth walls” or “straw bale walls”. The CSIRO has recently
established that rammed earth does not perform particularly well as an insulating material (as it has a low R-value).
However, it is an excellent source of thermal mass when inside the house, and near a north-facing window for that
low winter sun in southern Queensland. Straw bale construction provides an extremely high R-value and has been
used throughout Australia. It not only has good insulation properties, but is also one of the cheapest and most
sustainable alternative building products.
ii. Windows/Glass
Window size, location, glass (glazing) and frame type can significantly affect household heat loss and gain. Good
window selection can optimise the combination of natural lighting, ventilation, noise control, security and visual
amenity connecting interior and exterior spaces.
Normal glass has low insulation properties, hence the need for shading devices. Single glazing without curtains
achieves an R-value of 0.17. Double-glazing with a 12mm air space between the panes has an R-value of 0.34.
Some manufacturers are now producing insulating glass. Alternatives to standard clear glass windows, such as
“low-e” glass, reflective tinting or double-glazing with insulated window frames, are worth considering as they are
becoming more affordable and do not allow as much heat transfer into the room(s).
6
The Window Energy Rating Scheme (WERS) is a system that rates both the glass and frame performance of
windows. For more information on WERS and how to select the most energy-efficient windows for your house and
climate go to: www.wers.net
iii. Skylights
Skylights can improve indoor lighting by allowing natural sunlight to enter the house through the roof, thereby
reducing the need for artificial lighting and electricity. A skylight can be used in darker rooms and darker parts of
large rooms. Skylights should be well sized and located so as not to allow too much bright light to penetrate through
the roof, and also not to overexpose householders to direct indoor summer sun. Can these be retro-fitted > Ray?
Another new product being used for skylights is an acrylic sheet with laser-cut striations that allow a smaller
amount of heat and light through the acrylic panels in the middle part of the day when traditional skylights, if poorly
located, can allow too much heat and light into a room.
iv. Solar pergolas
Solar pergolas are shade structures that have angled blades, which prevent summer sun penetration (i.e.
roofs that are not waterproof), but can allow the low-angled winter light and warmth to enter between the
blades. Variations on the traditional solar pergola that allow the blades to be adjusted to the point of
closing them completely can provide an (almost) waterproof roof. They can be an invaluable feature to a
house in the sub-tropics and are ideal for the change in seasons.
Passive Design and its Benefits
The incorporation of passive design elements into a new or existing house can create a more comfortable home to
live in, save on its operating costs, as well as reduce its energy demand and greenhouse gas emissions. A passively
designed house looks like a conventional home – it just performs better. Given that an average house lasts for more
than 60 years, the integration of passive design is a wise investment choice as part of future-proofing your home and
making it perform more sustainably as it can effectively respond to a site’s prevailing climatic conditions.
Passive design traditionally aims to maintain a house’s thermal comfort without mechanical heating or cooling by
using natural energy flows – designing more with nature, not against it. A house’s ‘building envelope’ – it’s roof,
walls, windows and floors – fundamentally controls its heat gain in summer and heat loss in winter. Using passive
design to filter or modify a house’s building envelope to design for climate can significantly improve its thermal
performance. A well-designed building envelope will maximise cooling air movement and exclude sun in summer;
and, in winter, trap and store heat from the sun to minimise heat loss.
A passively designed house is well-orientated with good room zoning, maximises breezes for ventilation, is
effectively shaded and insulated, uses appropriate materials for energy-efficiency and optimises natural lighting
(refer to Figure 1 > p4 Passive Design Diagram). It can be built to be thermally comfortable on all but a handful
of days throughout the year, thereby minimising the need for artificial cooling or heating.
The benefits for owners of homes with passive design include lower energy costs and gaining a greater enjoyment
of Queensland’s climate when compared with residents of conventional houses. Whilst a house that incorporates
passive design features may cost slightly more upfront, it will become cost-effective over time through annual
operational savings, and therefore be more affordable in the longer-term. Homeowners do not need to pay hundreds
of dollars every year on heating and/or cooling costs if they take easy opportunities to access passive design (refer
to Figure 2 . p6 Insulation and Ventilation at Research House). Even where ideal conditions are not possible,
such as being able to gain good orientation, significant levels of improved comfort and energy efficiency can still be
obtained by incorporating other passive design principles.
Homeowners also have peace of mind given that their home has greater energy efficiencies, it will have a lower
greenhouse gas contribution through the reduction in burning of fossil fuels for electricity generation as it performs
more responsively to its prevailing climate.
What are ‘Climate Zones’ for Housing?
7
Climate zones assist in determining design and materials relevant to a defined region’s weather conditions to
improve a house’s thermal performance for comfort and energy efficiency. Climate zones are defined by the
Building Code of Australia (BCA) and administered through the Australian Building Codes Board (ABCB). They
are spatially categorised using local government areas. Queensland has four climate zones, these being (refer to
Table 1 and Figure 1):
 Zone 1 – Tropical
 Zone 2 – Sub-tropical
 Zone 3 – Hot Arid
 Zone 4 – Temperate (NB does not exist in Queensland)
 Zone 5 – Warm Temperate
Local Climatic Conditions
Local climatic conditions (i.e. microclimate) differ within each defined climate zone. For example, properties
located in coastal areas can have different seasonal temperature, humidity and wind differences (prevailing direction
and speed) from those located even less than 50 kilometres away in the hinterland. At a site level, passive design
responses need to account for this local climatic variation.
Research into local climate is recommended if undertaking passive design and this should include average:
- temperature ranges (both seasonal and diurnal (daily));
- humidity levels; and
- prevailing wind direction and speed.
The Bureau of Meteorology records and monitors this local climatic data across its local weather stations
throughout Queensland (refer to “References” below for this website to access data in your local area).
There is increasing evidence that global warming is already affecting annual averages in weather, such as
temperature and rainfall (for example, the total average annual rainfall has decreased by around 20% in the last 30
years for Perth). Passive design measures are recommended to appropriately reflect the significance of these
climatic changes to future-proof your house (refer to ‘Design for Global Warming’ below).
Site Context
Other local site elements such as lot size, configuration and orientation, topography (slope), vegetation and soil
type, will also fundamentally contribute to housing design, costs and operation. Consider how your plan interacts
with adjoining properties in terms of potential impacts, including the proximity of neighbouring buildings and/or
vegetation upon the site’s microclimate. For example, is the site located upslope or downslope; what is the solar
access/shading patterns (summer and winter); and how does stormwater flow across the site etc?
Site and Floor Plan Connections
The connection between the site and the floor plan needs to be carefully considered, as good indoor/outdoor
relationships are important in taking advantage of Queensland’s favourable outdoor lifestyle. For instance, avoid
having windows and outdoor living areas directly facing the same aspect of the neighbouring property. This will
minimise the impacts on solar access, visual and acoustic privacy, and allow interaction with your neighbours when
you want it.
House Size and Costs
The size of your house is the most important element in controlling its costs and environmental impact. Each square
metre of your floor plan will cost on average around $1200 to design and build, and every year thereafter directly
affect how much you spend on heating and cooling requirements. Essentially, buy or build your home to meet your
needs now and into the future.
Other Features of Sustainable Housing Design
8
Sustainable technology fittings, such as solar hot water systems, rainwater tanks and photovoltaic (solar) energy
supply, can significantly complement a passively designed house. All of these features are recommended to be
included as part of an integrated design response as they can collectively improve the efficiencies and performance
of a more sustainable house.
A more sustainable home can incorporate a range of features to account for energy and water supply and
consumption; accessibility; greywater and blackwater systems; stormwater management (minimising cut and fill onsite to maintain natural drainage patterns and detention basins, and preventing soil erosion/sediment and nutrient
run-off to our waterways); and biodiversity (through maintaining significant trees, as well as understory retention to
assist in preserving ecological values).
Designing for Global Warming (Climate Change)
The CSIRO predict that Australia will be hotter and drier in the coming decades due to global warming.
Increasingly warmer conditions are expected to produce more extremely hot days and fewer cold days. Annual
average temperatures are expected to rise, however this warming won't be the same everywhere. Queensland can
generally expect decreases in rainfall, but with more short and intense storms. Changes in rainfall patterns are
expected to lead to drier conditions across the continent. It is also predicted that there will be increases in wind
speed, occurrences of heatwaves and landslips. Planning and adapting to climate change is more important than
ever.
Given the lifespan of our housing, it is increasingly important to practically factor in these global warming issues
when passively designing a house. This includes building well above historic flood levels; designing stormwater
management systems for more intense rainfall; appropriate location and foundations if building on sloping sites;
using vegetation well adapted to drought/water-limited durations; and generally to incorporate passive design
features and materials to endure warmer and more extreme weather conditions, including intense storm events.
Passive Design and Air-Conditioners
With the decreasing cost of air-conditioners and their growing popularity, it is becoming realistic to expect that at
some stage most homeowners will install an air-conditioner, if only to deal with the extremes of uncomfortably hot
summer days. Decide early in the design stages if an air-conditioner is going to be used for such purposes, as a
different approach is required for passive design with an air-conditioner in order to maximise energy efficiency.
A well-considered passive designed house may include targeting major habitable room(s) that can be efficiently airconditioned, and whose function is flexible enough to accommodate a range of future uses. It can be beneficial to
record these adaptable design features to pass on to future owners to improve the house’s re-sale value.
A passively designed house can promotes energy efficiency by reducing the need for air-conditioning. The house
will be more comfortable throughout the year and the number of days when air conditioning is required will be
reduced. Selected room(s) can be created that are easy to mechanically cool. An air-conditioned room should have:
- insulated at the walls (internal and external), ceiling and floor; and
- sealable windows, doors and vents to restrict air escaping outside or to parts of the house that are not
directly subject to air-conditioning.
Sun exposure and internal heat transfer through standard clear glass can also be significant, so care should be taken
when designing air-conditioned spaces with window location, glass types and not to use more window area than is
necessary to create well-ventilated room(s) when an air-conditioner is switched off. Alternatives to standard clear
glass windows, such as “low-e” glass, reflective tinting or double-glazing with insulated window frames, are worth
considering as they are becoming more affordable and do not allow as much heat transfer into the room(s).
In cooler parts of Queensland, the principles for designing more efficient air-conditioned spaces also apply to
room(s) that may be heated.
Passive Design and Ceiling Fans
9
Although not strictly a passive design measure, all houses in Queensland are recommended to have ceiling fans or a
similar energy-efficient method of circulating air. Ceiling fans to all living and bedroom areas in a lightweight
house in Brisbane can typically turn a 3-star energy rated house into a 5-star energy rated house, and can effectively
cut cooling costs by up to 50%.
The cooling effect of air movement can greatly improve room comfort, potentially avoiding the need to install or
switch on an air-conditioner. Used together, a ceiling fan can allow an air-conditioner to run at more energyefficient levels e.g. by setting the air-conditioner temperature at 240C instead of more energy consuming 180C,
homeowners can save up to $150 a year on their electricity bills (or alternately, every 1 0C higher can save 10% on
operating costs). Additionally, ceiling fans cost less than air-conditioners to purchase and they generally only use
less than 10% of the energy required to operate, thereby making them much cheaper to run.
Ceiling fans with a reverse function option can similarly improve the efficiency of mechanical heating systems.
Most new ceiling fans have this reverse function option.
Passive Design Responses for Queensland’s Climatic Zones
Table 1 presents Queensland’s four climate zones and type, their prevailing weather characteristics and design
responses appropriate for each zone. Selected local government areas are also shown for each climate zone.
Table 1: Passive Design Responses for Queensland’s Climatic Zones
Climate
Zone 1
Climate Type
Prevailing Weather
Characteristics
Design Responses 2
1
Tropical
 high humidity with a
degree of ‘dry season’
 high temperatures year
round
 minimal seasonal
temperature variation
 low diurnal (day/night)
temperature range
 northern orientation
 site house/rooms to maximise
exposure to local breezes
 elevate building to permit
airflow beneath floors
 minimise building width for
cross ventilation
 high or raked ceilings
 use fully openable windows
(louvres or casements) to
maximise breezes
 provide operable ceiling
vents to all rooms
 ventilate roof spaces (popvents or slotted eaves with
fixed roof vents)
 shade windows and walls
(eaves) for summer and
winter
 use reflective insulation and
vapour barriers
 preferably use lightweight
construction (low thermal
mass)
 light coloured roof and wall
materials
 screen and shade outdoor
living areas
 design and build for cyclonic
conditions
 northern orientation
 site house/rooms to maximise
Selected Local
Government Areas
(& major township)
hot, humid year
round
2
Sub-tropical,
coastal
 high humidity with a
definite ‘dry season’
Cairns
Townsville
Thuringowa
Bowen
Burdekin (Ayr)
Douglas (Mossman)
Atherton
Cook (Weipa &
Cooktown)
Hinchinbrook (Ingham)
Johnstone (Innisfail)
Mornington Island
Brisbane region
10
Climate
Zone 1
Climate Type
Prevailing Weather
Characteristics
Design Responses 2
Selected Local
Government Areas
(& major township)
warm humid
summer, mild
winter
3
Hot Arid
hot dry summer,
warm winter
 hot summer, mild
winter
 distinct seasonal
temperature variation
 moderate to low
diurnal temperature
range, but varies
between coastal and
inland areas
 summer afternoon
breezes in coastal areas
 low rainfall and low
humidity
 very hot summer
 no extreme cold, but
cool in winter
 significant diurnal
temperature range
 hot, dry summer winds
exposure to local breezes
 allow passive solar access in
winter only
 minimise building width for
cross ventilation
 ventilate roof spaces (use
convective (stack)
ventilation, slotted eaves with
fixed roof vents)
 use fully openable windows
(louvres or casements) to
maximise breezes
 provide operable ceiling
vents to all rooms
 shade windows and walls
(eaves) for summer
 shade east and west walls and
glass year round (eaves)
 use reflective insulation and
bulk insulation
 use lightweight construction
where diurnal range is low;
include thermal mass where
diurnal range is significant
 light coloured roof and wall
materials
 screen and shade outdoor
living
 northern orientation
 site house for solar access
and exposure to cooling
breezes
 maximise cross ventilation
 use fully openable windows
(louvres or casements) to
maximise breezes
 provide operable ceiling
vents to all rooms
 ventilate roof spaces (use
convective (stack)
ventilation, slotted eaves with
fixed roof vents)
 shade east and west walls and
glass in summer (eaves)
 use reflective insulation and
bulk insulation in ceilings and
walls
 use passive design with
insulated thermal mass
 light coloured roof and wall
materials
 include external masonry
wall to provide enclosed
courtyard, protecting house
Sunshine Coast region
Gold Coast region
Ipswich
Beaudesert
Maryborough
Hervey Bay
Bundaberg
Gladstone
Rockhampton
Livingstone (Yeppoon)
Mackay
Fitzroy (Gracemere)
Nebo
Emerald
Longreach
Charters Towers
Mount Isa
Roma
Murweh (Charleville)
Banana (Biloela)
Barcaldine
Bauhinia (Springsure)
Belyando (Moranbah)
Booringa (Mitchell)
Chinchilla
Mundubbera
Murgon
Perry (Mount Perry)
11
Climate
Zone 1
Climate Type
Design Responses 2
Prevailing Weather
Characteristics
Selected Local
Government Areas
(& major township)


5
(note: climate
zone 4 does not
appear in
Queensland)
Warm
Temperate
hot humid
summer,
cool winter
 four distinct seasons
 low diurnal
temperature range in
coastal areas; high
diurnal range inland
 mild to cool winter and
low humidity
 hot to very hot summer
with moderate
humidity













from hot-dry prevailing
winds
shaded outdoor living areas
use garden ponds/water
feature for evaporative
cooling
northern orientation
maximise north facing walls
and glass, especially living
areas
site house for solar access,
cooling breezes and
protection from cold winds
minimise external wall areas,
especially east and west
use cross ventilation and
passive cooling in summer
use fully openable windows
(louvres or casements) to
maximise breezes
provide operable ceiling
vents to major habited rooms
ventilate roof spaces (use
convective (stack)
ventilation, slotted eaves with
fixed roof vents)
minimise all east and west
glazing, and use adjustable
shading (eaves)
use passive solar access with
high thermal mass, and bulk
and reflective insulation
light coloured roof and wall
materials
use heavy drapes with sealed
pelmets
use draught seal and entry
blocks
Toowoomba
Warwick
Stanthorpe
Kingaroy
Notes:
1
current climate zones for local government areas as categorised under the Building Codes of Australia (BCA) and
administered through the Australian Building Codes Board. These categories are subject to periodic review.
2
as adopted from “Your Home: Design for Lifestyle and the Future – Technical Manual” (2nd edition), Australian Greenhouse
Office, 2004.
12
Further information
It is recommended that you access specific information relevant to your local site and climate for design concepts
and costs if you intend to build a new house or renovate/re-fit your existing home. For example, refer to the “Your
Home Technical Manual” and/or Smart Housing publications, and discuss relevant passive design and materials
required with a local architect or building designer.
It is also recommended that you check proposed passive design drawings with relevant local council planning and
building provisions or developers covenants in order to satisfy relevant requirements for issues such as sub-division,
re-configuration, renovation/extensions, easements, boundary setbacks, height levels, character requirements,
fittings etc.
Your Home Technical Manual: www.greenhouse.gov.au/yourhome/technical/index.htm
Bureau of Meteorology: www.bom.gov.au/climate/averages
Smart Housing Design Objectives: www.housing.qld.gov.au/builders/smart_housing/pdf/design_objectives.pdf
Smart Housing Cost-efficiency Booklet: www.housing.qld.gov.au/builders/smart_housing/ce_booklet/index.htm
Sustainable Housing Fact Sheet: www.epa.qld.gov.au/publications/p01572aa.pdf/Sustainable_housing
CSIRO’s Global Warming Predictions: www.dar.csiro.au/publications/gh_faq.htm#gh22
Window Energy Rating System: www.wers.net
EcoSpecifier: www.
13
Glossary
Lightweight Construction
Thermal Mass
Photovoltaic (Solar) Energy Supply
14
Queensland’s Climate Zones
Queensland contains four climate zones that are depicted in Figure 1. Passive design features differ across each of
these zones to account for the prevailing climatic conditions. Regulations are also applied at the particular local
government level through the Building Code of Australia.
Figure 1: Queensland’s Climate Zones for Thermal Housing Design
Map reproduced with kind permission of Australian Building Codes Board
Insert ABCB Logo
Note:
This map is derived from the current reference map used to apply the BCA (as at 2005). Classifications for local government
areas are subject to periodic review by the Australian Building Codes Board and may alter with updated information. For
further information go to: www.abcb.gov.au
15
DISTRIBUTION LIST
Ray Jones
Craig Ingram
Sue Crozier
Damian Dewar
Ross Mehrten
Wayne Petrie
Andrew Aitken
David Mills
Shawn Godwin
John Moynihan
16