The Light to Heat Ratio: Why Perth Homeowners Shouldn’t Have to Choose

Perth is one of the sunniest cities in the world. Even in winter, we’re lucky enough to enjoy bright, clear days filled with natural light.

But for many homeowners, winter living comes with a frustrating compromise.

You want the sunlight.

But you don’t want the cold that follows.

So what happens? The curtains come down.

Heavy, dark thermal curtains stay closed most of the day, trapping warmth inside, but also shutting out natural light. Rooms feel dim. Artificial lights stay on. And despite all that effort, the house still never quite feels warm enough.

This is what we call the “heavy curtain trap”, and it’s more common in Perth homes than you might think.

Why Perth Homes Struggle with Winter Comfort

Most Perth homes are built to handle heat, not cold.

Single pane windows, especially those paired with aluminium frames, offer very little insulation. As soon as the sun sets, heat escapes quickly through the glass and frame. During the day, even with sunlight streaming in, that warmth doesn’t stay trapped inside.

The result:

• Sunlight = warmth during the day
• Rapid heat loss at night
• A constant cycle of heating and cooling

To compensate, homeowners close curtains early, blocking heat loss but also natural light.

The Problem With Closing Your Curtains All Day

While thermal curtains can help reduce heat loss, they come with trade offs:

• Rooms become darker and rely on artificial lighting
• Reduced exposure to natural daylight
• Spaces feel smaller and less inviting
• You miss out on winter sun, one of Perth’s biggest advantages

It’s a compromise between light and warmth, one that most homeowners have simply accepted. But it doesn’t have to be that way.

What Is the ‘Light to Heat Ratio’?

Think of your windows as a balance between two things:

• Light gain (natural sunlight entering your home)
• Heat retention (keeping warmth inside)

With older windows, improving one often means sacrificing the other.

• Want more warmth? Close the curtains → lose the light
• Want more light? Open the curtains → lose the heat

Modern double glazing changes that equation completely.

How Double Glazing Lets You Have Both

Double glazed windows are designed to improve insulation without blocking natural light.

They work by:

• Using two panes of glass instead of one
• Creating an insulating air gap between them
• Reducing heat transfer in and out of the home

This means:

• Sunlight can enter and warm your home during the day (passive solar gain)
• Heat stays inside for longer once the sun goes down
• Internal glass stays warmer, reducing cold radiation

In simple terms: You can leave your curtains open, and your home stays comfortable.

Passive Solar Gain: Perth’s Winter Advantage

Perth’s sunny winters are actually a huge opportunity IF your home is designed to take advantage of it.

Passive solar gain refers to using sunlight to naturally warm your home during the day. When sunlight enters through windows and is retained effectively, it reduces the need for artificial heating.

Double glazing enhances this by:

• Allowing visible light through
• Slowing heat loss
• Maintaining a stable indoor temperature

Instead of fighting the cold, your home works with the sun.

Why uPVC Frames Make a Difference

Glass isn’t the only factor.

Standard aluminium frames act as a thermal bridge, pulling heat out of your home even when the sun is shining. This undermines the benefits of sunlight and insulation.

uPVC frames, like those used by Formalux, solve this problem.

They are:

• Non conductive, preventing heat transfer
• Airtight, reducing draughts
• Stable, maintaining performance over time

Combined with double glazing, they ensure warmth stays where it belongs – inside your home.

A Brighter, Warmer Way to Live

Imagine a winter day where:

• Curtains stay open
• Rooms are filled with natural light
• Floors feel warmer
• Heating is used less
• Evenings stay comfortable for longer

That’s the difference high performance double glazing makes.

It’s not just about insulation. It’s about transforming how your home feels and functions throughout winter.

Why Perth Homeowners Are Moving Beyond Curtains

Heavy curtains were once the only option.

But today, more Perth homeowners are choosing to upgrade their windows instead of relying on workarounds. It’s a long term solution that addresses the root cause, not just the symptom.

With Formalux double glazed windows and uPVC frames, you no longer have to choose between light and warmth. You get both.

FAQs: Light, Heat & Double Glazing in Perth

Do I need to close curtains with double glazing in winter?
Not during the day. Double glazing allows you to keep curtains open to enjoy natural light and passive solar warmth while still retaining heat inside.

Does double glazing let sunlight in?
Yes. Double glazed windows allow natural light to pass through while reducing heat loss, maintaining a bright and comfortable interior.

What is passive solar heating in a home?
Passive solar heating uses sunlight entering through windows to naturally warm indoor spaces, reducing reliance on heaters during the day.

Why do aluminium window frames feel cold?
Aluminium is highly conductive, meaning it transfers cold temperatures inside — creating heat loss even when sunlight is present.

Are uPVC windows better for insulation than aluminium?
Yes. uPVC frames are non conductive and provide superior insulation, helping to retain heat and eliminate draughts.

Will double glazing reduce my heating bills in winter?
Yes. By reducing heat loss and improving thermal efficiency, double glazing helps lower heating demand and energy costs.

Is double glazing worth it in Perth’s mild winters?
Absolutely. Even mild winters can feel cold in poorly insulated homes. Double glazing improves comfort, reduces draughts and makes better use of Perth’s winter sun.

Stop Choosing Between Light and Heat

In a city as sunny as Perth, no one should have to live behind closed curtains all winter.

With the right glazing, your home can feel warmer, brighter and more comfortable, all at once.

Contact Formalux today to discover how double glazing can transform your winter living and finally get the balance right.