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

Window Film vs Blinds: Which Blocks More Heat?

Quick Verdict

External blinds block up to 80% of heat and are most effective. Window film blocks 30-60% of heat but is cheaper and works for renters. Internal blinds block only 20-30% of heat. For maximum impact, use external shading; for budget or rentals, use window film.

Side-by-Side Comparison

Factor	Window Film	Blinds (External vs Internal)
Upfront Cost	$30-$80/window DIY, $80-$150/window professional	$50-$200/window internal, $150-$500/window external
Running Cost	$0 (passive)	$0 (passive)
Cooling Power	Blocks 30-60% of solar heat	External: 80% heat block, Internal: 20-30%
Best Climate	All climates	All climates
DIY Install?	Yes	Yes

Window Film

Applied directly to glass. Reflects or absorbs solar heat before it enters the room.

Pros

Renter-friendly (static cling options)
Invisible from inside
Also blocks UV (protects furniture)
No maintenance required
Works on all window types

Cons

Less effective than external shading
May void window warranty
Reflective films may breach strata rules
Needs replacement every 10-15 years
Cannot be adjusted seasonally

Blinds (External vs Internal)

Physical barriers that block sunlight. External blinds are far more effective than internal.

Pros

External blinds are most effective solution
Adjustable - open in winter, close in summer
Variety of styles to suit home
Long lifespan (10-20+ years)
Can improve privacy

Cons

Internal blinds trap heat between blind and glass
External blinds need installation/maintenance
External options may need council approval
Not all rentals allow external mounting
Manual operation requires daily effort

Climate Zone Guide

Hot-Dry Climates (WA, SA, Inland)

External blinds or shade sails are ideal - they block heat before it hits the glass. Window film is a good secondary option. Avoid relying solely on internal blinds.

Hot-Humid Climates (QLD, NT)

External shading is critical. Window film helps reduce AC load. Combination of external blinds on west windows + film on other windows is cost-effective.

Temperate Climates (VIC, NSW, ACT)

Window film offers year-round benefits without blocking winter sun. Consider adjustable external blinds if you want seasonal flexibility.

Cost Analysis

Window film costs $200-$600 for a typical home (4-8 windows) and saves $60-$150/year on cooling. Payback: 2-5 years. External blinds cost $600-$2,000 for key windows and save $150-$300/year. Payback: 3-7 years. Internal blinds have minimal cooling impact and are primarily for privacy/light control.

Frequently Asked Questions

Which is better for renters?

Window film - specifically static cling films that don't require adhesive and peel off easily when you move. Portable shade screens that sit outside windows are another option. Most internal blinds come with the rental anyway.

Can I use both window film and blinds?

Yes, and this is often the best approach. Apply film to reduce baseline heat transfer, then use blinds for additional control. External blinds + film is the ultimate combination, reducing heat gain by up to 90%.

Do honeycomb blinds work better than regular blinds?

Honeycomb (cellular) blinds are the best internal blind option, with the air pockets providing some insulation. They block about 30-40% of heat vs 20-25% for standard blinds. Still far less effective than external shading or window film.

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