17 Things

Cross-ventilation occurs when there are breeze paths through a home, from one side to the other, naturally cooling without relying on mechanical air-conditioning. It can also help to create a healthy home by discouraging mould.

No 4. Cross-ventilation

The 17 Things

What is it?

Cross-ventilation occurs when there are existing breeze paths through a home, from one side to the other. It is an important means of providing natural, low energy thermal comfort. It may be assisted by external breezes, but is not reliant on them: good cross-ventilation will also occur when the air is still. Of course, if cooling breezes are available in summer, these should be encouraged to move right through the home especially in the cooling climates in the top end of Australia, such as Darwin.

Having a floor plan that provides effective and natural breeze paths is the basis for effective cross-ventilation. That is, an approximate alignment of windows and external doors with internal doors and passageways, which allows air movement with little or no “snaking” through complex layouts.

Cross-ventilation floor plan

Floor plans that allow breezes to flow through the house result in natural cooling and a healthy home.
Image credits to Livingworld Building Studio www.livingworld.co.in/

It is complementary to several other Liveability Features™, and is a key element in passive cooling. This occurs when a home’s internal heat load, stored in dense building materials, is allowed to vent to the night sky, a process called “night purging”. This occurs when there is a temperature difference between internal and external air even when there is minimal breeze.

With temperature differences come pressure differences, and with pressure differences come instability and movement – the warm air will begin escaping by convection to the night sky. But as the pressure differences are slight, resistance must be minimised, which is why a simple floor plan without convoluted pathways is important.

How will it help me reduce my running costs and increase my comfort?

Encouraging cool breezes and/or night purging of dense materials will act to regulate internal temperatures. Passive design can provide delightful natural comfort, and reduce or even eliminate the need for artificial heating or cooling energy.

A home with good cross-ventilation is also a healthy home, as the natural breezes that flow through the house will discourage mould from growing on the interior.

If the home can be significantly or wholly cooled without the use of artificial energy, the running costs will be dramatically reduced. This has several obvious benefits, both to the home owner and to prospective purchasers.

What professional should I talk to about this?

The Centre for Liveability Real Estate always recommends you consult further with any relevant specialist design or building consultants or assessors before making any decision regarding your specific property based on the Liveability Property Marketing Features™.

Most architects, building designers and some builders understand how cross-ventilation works and how it combines with other Liveability Features in passive design, and have the skills needed to optimise it. They include HIA GreenSmart builders and designersMaster Builders Green Living buildersBDA and BDAV (VIC only) building designers.

Finding the potential in existing homes is not difficult, especially if the house has a good layout, or a floor plan that can be easily altered to optimise cross-ventilation.

Is there anything I need to know before I meet with them?

Having an understanding of the cross-ventilation patterns that do work in your existing home will be useful, as is knowing where the welcome breezes come from. There may be obstacles in the immediate vicinity which cause unexpected effects – your local knowledge will be valuable.

Being clear about what you want to achieve is important, and having a clear understanding of the basics, so you can have confidence your builder or designer knows what they are talking about.

Breezes suck through openings rather than blow in so having any existing plans of your house will also help them conceptualise a design solution.

What is the price range I can expect?

A detailed appraisal of your home may take a couple of hours, depending on its size and complexity. Further work will be highly variable according to your brief (the expression and record of what it is you want and need). Allow upwards of $300, pending inclusion of a broader assessment of other issues (refer to other items in the list of the 17 Things™).

Where can I find more information?

There are several good sources for further reading, but the single best place to start is the Your Home: Australia’s Guide to Environmentally Sustainable Homes, with its excellent introduction to cross-ventilation in passive design.

Warm House Cool House by Nick Hollo is another great resource in understanding how to cool the home using natural breezes.

If I already have this feature, is there anything I need to know about using it effectively?

Convection occurs when hot (thinner, lighter) air rises and cold (denser, heavier) air falls. Opening windows in the upper levels helps this hot air to escape out the top and draw cool breezes in from the bottom.

Convection occurs when hot (thinner, lighter) air rises and cold (denser, heavier) air falls. Opening windows in the upper levels helps this hot air to escape out the top and draw cool breezes in from the bottom.
Image credits to Your Home www.yourhome.gov.au

If your home’s layout already provides for easy breeze paths across its floor plate, the best thing you can do – and this is very simple, and costs nothing – is use them! Open the appropriate windows and doors, and allow the breeze to flow through, or allow the night purge to take place. Look for windows with large opening areas, such as louvre windows and casement windows, as they provide maximum flow.

Ensure you keep your flyscreens clean to allow more of the breeze in.

Does this work better when combined with any of the other 17 Things™

Cross-ventilation complements many of the 17 Things™ as it represents free cooling. When combined with No. 9 Shading or Sun Control measures, cross-ventilation will work better to create a comfortable temperature. If you are in a cooling climate (not tropical) cross-ventilation can move the hot air out of the building and replace with the cooler night air. And it can help make No 6. Insulation and No 7. Density of Building Materials more effective.

Will this feature be recognised when I sell my property?

Yes; Liveability Real Estate Specialist sales agents and property managers have been upskilled to identify an additional 17 Things™ on top of a standard property appraisal. So if you have invested in any of the 17 Things™ this means your property will be appraised and marketed with real skill and with the best marketing resources for online and print media.

You can book a free property appraisal with a Liveability Real Estate Specialist any time you’re ready to sell or even if you’re not planning to sell for a couple of years. Each of the 17 Things™ has appraisal benchmarks (relevant to existing and new homes) which have been set by relevant industry partners to make sure we deliver a high standard of property marketing. So your Liveability Real Estate Specialist will work through this appraisal checklist with you as they move through your home. It’s a great chance for you to let them know about all the property features you have invested in.


Any questions?

We’re here to help! Just send us your enquiry.

What is it?

Cross-ventilation occurs when there are existing breeze paths through a home, from one side to the other. It is an important means of providing natural, low energy thermal comfort. It may be assisted by external breezes, but is not reliant on them: good cross-ventilation will also occur when the air is still. Of course, if cooling breezes are available in summer, these should be encouraged to move right through the home especially in the cooling climates in the top end of Australia, such as Darwin.

Having a floor plan that provides effective and natural breeze paths is the basis for effective cross-ventilation and air flow through the house, between floors and under the house. That is, an approximate alignment of windows and external doors with internal doors and passageways, which allows air movement with little or no “snaking” through complex layouts.

Cross-ventilation floor plan

Floor plans that allow breezes to flow through the house result in natural cooling and a healthy home.
Image credits to Livingworld Building Studio www.livingworld.co.in/

It is complementary to several other Liveability Features™, and is a key element in passive cooling. This occurs when a home’s internal heat load is allowed to vent to the night sky, a process called “night purging”. This occurs because there is a temperature difference between internal and external air even when there is no breeze.

With temperature differences come pressure differences, and with pressure differences come instability and movement – the warm air will begin escaping by convection to the night sky. But as the pressure differences are slight, resistance must be minimised, which is why a simple floor plan without convoluted pathways is important.

Houses in the cooling climate that have been designed as “free running” or naturally cooled will generally have effective cross-ventilation.

Your local council and state or territory government may also have free information available for you to download, such as the Queensland Government and their tips for smart and sustainable homes. Make sure to look out for resources specific to the tropical climate.

How will it help me reduce my running costs and increase my comfort?

Encouraging cool breezes and/or night purging will act to regulate internal temperatures. Passive design can provide delightful natural comfort, and reduce or even eliminate the need for artificial cooling.

A home with good cross-ventilation is also a healthy home, as the natural breezes that flow through the house will discourage mould from growing on the interior.

If the home can be significantly or wholly cooled without the use of artificial energy, the running costs will be dramatically reduced. This has several obvious benefits, both to the home owner and to prospective purchasers.

What professional should I talk to about this?

The Centre for Liveability Real Estate always recommends you consult further with any relevant specialist design or building consultants or assessors before making any decision regarding your specific property based on the Liveability Property Marketing Features™.

Most architects, building designers and some builders understand how cross-ventilation works and how it combines with other Liveability Features in passive design, and have the skills needed to optimise it. They include HIA GreenSmart builders and designersMaster Builders Green Living builders and BDA building designers.

Finding the potential in existing homes is not difficult, especially if the house has a good layout, or a floor plan that can be easily altered to optimise cross-ventilation.

Is there anything I need to know before I meet with them?

Having an understanding of the cross-ventilation patterns that do work in your existing home will be useful, as is knowing where the welcome breezes come from.

There may be obstacles in the immediate vicinity which cause unexpected effects – your local knowledge will be valuable.

Being clear about what you want to achieve is important, and having a clear understanding of the basics, so you can have confidence your builder or designer knows what they are talking about.

Breezes suck through openings rather than blow in so having any existing plans of your house will also help them conceptualise a design solution.

What is the price range I can expect?

A detailed appraisal of your home may take a couple of hours, depending on its size and complexity. Further work will be highly variable according to your brief (the expression and record of what it is you want and need). Allow upwards of $300, pending inclusion of a broader assessment of other issues (refer to other items in the list of the 17 Things™).

Where can I find more information?

There are several good sources for further reading, but the single best place to start is the Your Home: Australia’s Guide to Environmentally Sustainable Homes, with its excellent introduction to cross-ventilation in passive design.

Warm House Cool House by Nick Hollo is another great resource in understanding how to cool the home using natural breezes.

COOLmob also has information on designing for the tropics  that include cross-ventilation.

If I already have this feature, is there anything I need to know about using it effectively?

Convection occurs when hot (thinner, lighter) air rises and cold (denser, heavier) air falls. Opening windows in the upper levels helps this hot air to escape out the top and draw cool breezes in from the bottom.

Convection occurs when hot (thinner, lighter) air rises and cold (denser, heavier) air falls. Opening windows in the upper levels helps this hot air to escape out the top and draw cool breezes in from the bottom.
Image credits to Your Home www.yourhome.gov.au

If your home’s layout already provides for easy breeze paths across its floor plate, the best thing you can do – and this is very simple, and costs nothing – is use them! Open the appropriate windows and doors, and allow the breeze to flow through, or allow the night purge to take place. Look for windows with large opening areas, such as louvre windows and casement windows, as they provide maximum flow.

Ensure you keep your flyscreens clean to allow more of the breeze in.

Does this work better when combined with any of the other 17 Things™

Cross-ventilation complements many of the 17 Things™ as it represents free cooling. When combined with No. 9 Shading or Sun Control measures, cross-ventilation will work better to create a comfortable temperature.

Will this feature be recognised when I sell my property?

Yes; Liveability Real Estate Specialist sales agents and property managers have been upskilled to identify an additional 17 Things™ on top of a standard property appraisal. So if you have invested in any of the 17 Things™ this means your property will be appraised and marketed with real skill and with the best marketing resources for online and print media.

You can book a free property appraisal with a Liveability Real Estate Specialist any time you’re ready to sell or even if you’re not planning to sell for a couple of years. Each of the 17 Things™ has appraisal benchmarks (relevant to existing and new homes) which have been set by relevant industry partners to make sure we deliver a high standard of property marketing. So your Liveability Real Estate Specialist will work through this appraisal checklist with you as they move through your home. It’s a great chance for you to let them know about all the property features you have invested in.


Any questions?

We’re here to help! Just send us your enquiry.

The 17 Things

The 17 Things

The 17 Things™ are property features that have the potential to reduce running costs and increase comfort if used correctly. You can discuss incorporating these into your renovation with with your architect, building designer or builder. The real estate industry is now identifying these Liveability Property Features™at point of sale or rent through agents that have completed additional training as Liveability Real Estate Specialists.

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