Heat Gains – Ways to Combat the Rising Temperatures in our Homes

So, we are heading for another hot summer and, yes, climate change is upon us.  How are we, as homeowners, going to cope with the inevitable increase in heat and yet maintain the lowering greenhouse gases – the quandary we face in the 21st century?  Just turn on the air conditioner you may well say – we have them in our offices and cars – why can’t we have them in our homes?  Or, hang on, should we be listening to the environmental experts? Or the building regulators? Or simply the folk who have managed to do it the most efficient way without destroying the planet and yet live in eco-friendly cool “Kool” homes?

There are many ways to keep our homes cool without going the traditional cool air conditioning route.  Think of our grandparents who did not have any mod cons – how did they cope? They built with thicker walls, they closed windows and used thick heavy curtains. Washing was sometimes put inside so that the dampness could spread through air circulation.  They left wet sheets to blow indoors and had wind towers to blow air around. Some of them lived in caves.

Heat Gain – what does it actually mean?

Well for homes, having heat gain – this is an engineering term – means an increase in temperature in the home due to solar radiation and the heat radiated by people, electric lighting and equipment. 

Well, yes, we have solar radiation for sure and lots of new gadgets and home comforts that not only take up space but generate more heat.  Add to this, more people in the home and those kids running around – you are going to get heat gain in the house.  Most uncomfortable indeed.

What does this Heat Gain cost and where are the culprits in the home?

About 40% of all the energy used in Australian homes comes from both heating and cooling. Note to those who simply want to pay their way out of this heat gain by installing a new cooling gadget: if you want to lower the temperature by 1-degree C you are increasing your energy consumption by approximately 5-10%.

Some other summer heat gains facts:

  • Heat coming through windows accounts for about 25-35%
  • Through the ceiling about 25-35%
  • Through walls about 15-25%
  • Through floors about 10-20%
  • Through floor leakage 0-25%

So, perhaps we need to build a new, improved, eco-friendly house, or insulate our existing one, or go back to the cave. We need to re-consider all aspects of the structure of our home.  What can we do about the floors, the windows, the roof?  Should we go back to the old ways of putting cardboard on the windows, or going to bed with a cool watermelon to cuddle? Or turning the bedroom into a drip irrigation system? Perhaps plant lots of trees to insulate the roof or throw some shade-netting over all exposed walls. So much to do and so little time – summer is upon us.

Simple Solutions to how to combat Heat Gains and stop those sweaty nights in our homes

  • Insulate your home in all the above features.
  • Use proper shading techniques for windows, and those big sliding let-the garden-in doors.
  • Ventilate – not from the western side of the home.
  • Be environmentally aware – don’t use mechanical cooling when you can substitute for proper eco-friendly design.
  • Look within the house structure before buying expensive cooling equipment solutions.
  • Design principles should be as passive as possible. Not only will they keep the temperature from getting to you but they will do it guilt-free.
  • Night time temperatures are on the rise, as well as day time temperatures, so in some instances cooling machines are a necessity – just ensure they are as passive as possible.
  • Try and shade your roof.
  • Grow creepers up walls – especially on the western, high heat, side of your home.
  • Old roofs need to be assessed for proper insulation equipment – the latest techniques will take your bills and the temperature down.
  • Remember that your roof takes the most hammering from the heat of the day and by having a proper insulated one with good ventilation you may find yourself with a 25-30% better cooled home. Something to brag about.  (In winter of course energy going out of the roof is a big factor too.)
  • Install whirly-birds to ventilate and stop condensation – best to have two on either side of the house. This will help in getting that air moving.


Most of all, use your common sense to beat the onslaught of heat gain within your home.  Speak to the experts and look at the main contributors of higher costs in your home: ceilings, walls, floors, windows and the roof. But most of all, investing in an energy efficient abode is the right way to go.  There is always the cave to go back to if you must.