What research are the recommendations based on?

Our recommendations are built on authoritative Australian sources: the Australian Government's YourHome guide (yourhome.gov.au) for passive cooling principles, the National Construction Code (NCC) climate zone classifications, CSIRO housing research on thermal comfort, and NatHERS energy rating guidelines. Product recommendations feature items rated by CHOICE and verified on ProductReview.com.au.

Is CoolMyHouse really free?

Yes, completely free with no catches. You get personalised recommendations, a PDF action plan, and shareable results. We don't sell your data. Some product links are affiliate links (we may earn a small commission if you purchase), but this doesn't affect which products we recommend.

I already have air conditioning. Will this help me?

Absolutely! Many of our highest-impact recommendations help you use your existing AC more efficiently. We'll suggest strategies like optimising your ducted zone controls, pre-cooling before heatwaves, using ceiling fans alongside AC (which lets you set the thermostat 2-3°C higher), and reducing heat gain so your AC doesn't work as hard.

We've got you covered. When you select 'rent', we automatically filter to non-permanent solutions: portable evaporative coolers, removable window film, internal blockout blinds, door draft stoppers, and behavioral strategies like night purging and cross-ventilation.

Does this work for apartments and units?

Yes! While some recommendations are house-specific (like roof ventilation), many apply equally to apartments: window film, internal blinds, ceiling fans, sealing air gaps, cross-ventilation strategies, and portable cooling options.

What about two-storey homes?

Two-storey homes have unique challenges - heat rises, making upper floors significantly hotter. We provide specific recommendations: ensuring adequate ceiling insulation, installing ceiling fans on the upper floor, using stairwell doors to contain cool air, and optimising ducted AC zones.

How much can I actually save?

Typical Australian households spend $600-1,200/year on cooling. Our users commonly save 30-50% by implementing high-impact recommendations. External shading on west windows can save $100-250/year, ceiling fans used with AC can save $100-300/year, and proper ceiling insulation can save $180-400/year.

What makes west-facing windows so critical?

The afternoon sun (1-6pm) hits west-facing windows at a low angle, penetrating deep into rooms. A large unshaded west window can add 1-2kW of heat - equivalent to running a bar heater! External shading blocks 80% of heat before it enters, while internal blinds only block 20-30%.

How do climate zones affect my recommendations?

Australia has 8 distinct climate zones, and strategies that work in Perth can fail in Darwin. In hot-dry climates (WA, SA) with humidity under 40%, evaporative cooling is excellent. In hot-humid climates (QLD, NT) with 60-80% humidity, evaporative cooling is ineffective - you need refrigerative AC instead.

Can I trust the product recommendations?

We only recommend products that are highly rated by Australian consumers (4+ stars), readily available (Bunnings, Amazon AU), and appropriate for your situation. Some links are affiliate links, but this never influences our recommendations.

Can I share my results?

Yes! You can share via a unique link (which includes your assessment data so others see your specific recommendations), get a detailed PDF report emailed to you, or print the page.

CoolMyHouse

Single Glazing vs Double Glazing Windows

Quick Verdict

Double glazing reduces heat transfer by 50% and is worthwhile for new builds or full renovations. For existing homes, window film or external shading often provides better value. Consider double glazing for extreme climates or if also addressing winter heating.

Side-by-Side Comparison

Factor	Single Glazing	Double Glazing
Upfront Cost	$200-$400 per window	$600-$1,200 per window
Running Cost	Higher heating/cooling costs	Lower heating/cooling costs
Cooling Power	Minimal insulation	50% less heat transfer
Best Climate	Mild climates only	All climates (especially extreme)
DIY Install?	No	No

Single Glazing

Standard windows with one pane of glass. Most common in existing Australian homes.

Pros

Lower upfront cost
Already installed in most homes
Adequate for mild climates
Can add film for improvement
Easy to repair/replace

Cons

Poor insulation (U-value 5-6)
Heat pours through in summer
Cold in winter
Condensation issues
Higher ongoing energy costs

Double Glazing

Two panes of glass with air or gas gap providing insulation.

Pros

Halves heat transfer (U-value 2.5-3)
Also improves winter warmth
Reduces condensation
Blocks more noise
Increases property value

Cons

High upfront cost
Retrofitting is expensive
May need new frames
Long payback period (10-20 years)
Heavier than single glazing

Climate Zone Guide

Hot-Dry Climates (WA, SA, Inland)

Double glazing helps but external shading is more effective for blocking summer heat in hot-dry climates. The main benefit is reducing AC runtime. Payback is 15-20 years for cooling alone.

Hot-Humid Climates (QLD, NT)

Double glazing reduces AC load in hot-humid climates. Combined with low-E coating to reject solar heat, it can significantly reduce cooling costs. More beneficial than in dry climates.

Temperate Climates (VIC, NSW, ACT)

Double glazing is most beneficial in temperate climates where both heating and cooling are needed. The combined savings on both make payback more reasonable (10-15 years).

Cost Analysis

Retrofitting double glazing typically costs $8,000-$20,000 for an average home. Energy savings are roughly $200-$500 per year (depending on climate and usage). Payback period is 15-40+ years. For new builds, the additional cost is only $2,000-$5,000, with payback of 5-10 years.

Frequently Asked Questions

Is double glazing worth it in Australia?

For new builds: definitely yes, the additional cost is modest. For retrofitting existing homes: usually not cost-effective as a standalone upgrade. External shading, ceiling insulation, and draught sealing offer better return on investment for most homes.

What alternatives to double glazing reduce heat?

External shading (blocks 80% of heat) is most effective. Window film (blocks 30-60% of heat) costs $300-$600 per window. Secondary glazing (perspex panels) costs 30-50% less than replacement double glazing. Thermal curtains help with both heating and cooling.

Does double glazing help with cooling or just heating?

Both, but the benefit is typically greater for heating in Australian climates. For cooling, external shading is more effective because it stops heat before it hits the glass. Double glazing with low-E coating does reduce radiant heat gain and AC loads.

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