Melbourne May Be Cold Now But Believe Us, It Can Get Hotter: A Practical Guide to Keeping Your Home Cool

Melbourne May Be Cold Now But Believe Us, It Can Get Hotter: A Practical Guide to Keeping Your Home Cool

Melbourne’s climate is famous for its mood swings. One week it’s jumpers and drizzle, the next it’s a dry northerly and a 35°C afternoon that lingers into a warm night. If your living room bakes after 3pm, bedrooms feel stuffy at bedtime or the air-con never seems to stop, you’re not imagining it. The good news: you don’t need a major renovation to reduce heat gain. With a layered approach – shading, sealing, smart ventilation, and better window double glazing – you can keep rooms cooler, lower energy use and make hot spells far more liveable.

Below is a Melbourne-targeted insulation plan that would give you an immediate result. It suits everything from heritage terraces and Californian bungalows to modern apartments and townhouses.

Think in Layers: The “Cooling Stack”

Lasting summer comfort isn’t about one product – it’s the stack. Each layer reduces heat load so the next one works better.

  1. Block the sun before it hits your window.
  2. Seal heat paths and reduce radiant warmth from glass.
  3. Ventilate at the right times (not all the time).
  4. Upgradewindow glazingto cut conductive and radiant heat.
  5. Run cooling more efficiently, less often.

Let’s break that down.

1) Shade First: Keep Sun Off the Glass

External shadingis your first, best line of defence especially for west-facing rooms from 2–7pm.

  • Awnings or external blinds:Retractable can dramatically cut afternoon heat.
  • Pergolas/louvres:Filter harsh sun while preserving light and airflow.
  • Deciduous planting:Leafy shade in summer, sunlight in winter – ideal for north aspects.
  • Solar control films:Reduce glare and UV; useful where external shading isn’t possible (apartments/strata).

Why it matters:Shading stops heat before it becomes an indoor problem. Every degree you prevent at the window is a degree your air-con doesn’t need to fight.

2) Seal the Envelope: Stop Heat Leaks

If air moves, heat moves. Tiny gaps around sashes, sliding tracks and architraves act like little chimneys.

  • Weather seals & door sweeps:Low-cost, quick to install, surprisingly effective.
  • Curtains that work:Lined, full-height drapes or cellular blinds create an insulating air layer and cut radiant heat from warm glass.
  • Fix the “small leaks”:Pet doors, exhausts without back-draft dampers, letterbox flaps – add covers or baffles where practical.

Winter bonus:These same measures reduce draughts and improve cold-weather comfort.

3) Ventilate Strategically (Not Randomly)

Opening windows at the wrong time brings in hot, dry air and raises indoor temperature.

  • Night purging:Ventilate when outside air is cooler/drier than indoors (late evening/early morning).
  • Cross-flow:Open lower windows on the cool side and upper vents or opposite windows to flush warm air.
  • Fans:Ceiling or pedestal fans boost perceived cooling at a fraction of AC energy.

When northerlies are hot and dry, limit intake and rely on fans/AC until the cool change arrives.

4) Upgrade Window Glazing: The Biggest Single Improvement

Windows are typically the weakest thermal link. Single panes conduct heat quickly and radiate it into rooms long after sunset.Double glazing window solutionsaddress this with two panes separated by a sealed air (or gas) gap, cutting conductive/convective transfer. Add alow-E coatingand you reduce radiant heat too.

Two Options for Existing Homes in Melbourne

Full replacement
Install new double-glazed window units with modern window frames.

  • Pros:Maximum design flexibility; can use thermally broken window frames.
  • Cons:Higher cost, more disruption; potential heritage/strata constraints.

Retrofit double glazing windows
Add a custom secondary panel to theinsideof your existing window frame, creating a high-performance air gap without replacing the window.

  • Pros:Significant summer heat reduction and winter warmth; excellent for noise (trams, traffic, venues); minimal disruption; suits heritage and apartments.
  • Cons:You’re working with the existing frame aesthetics/opening style.

Where solutions like Magnetite fit:Magnetite’s Retrofit double glazing window solution integrates with existing windows to reduce heat transfer and stabilise room temperatures, particularly on west- and north-facing glass. Pairing with quality perimeter seals and (where glare is harsh) solar control film creates a layered solution that keeps rooms cooler for longer and reduces AC runtime.

5) Run Cooling Smarter, Not Harder

Once shading, sealing and glazing are doing their job, your cooling can do less.

  • Setpoint:24–25°C is a sweet spot for comfort and efficiency.
  • Zone it:Cool the rooms you’re using; close doors and draw curtains in unused spaces.
  • Service:Clean filters and check seals so systems run as intended.
  • Fans + AC:Fans let you nudge the thermostat up a degree or two without losing comfort.

Room-by-Room Priorities for Melbourne

West-facing living rooms (the 3–7pm problem)

  • External awnings/sails
  • Retrofit double glazing windowsand lined curtains
  • Solar control film if glare is severe
  • Ceiling fan to extend comfort window before AC

Street- or tram-facing bedrooms

  • Retrofit double glazing windows for heat and noise (sleep better with windows closed)
  • Door sweep + lined curtains
  • Night purge when air is cooler

Home office (inner-city, near transport)

  • Retrofit double glazing windows to cut heat and daytime noise
  • Desk fan + zoned cooling
  • Cellular blind for daytime solar control

Heritage terraces & period homes

  • Internal retrofit window solutions respect façades and sashes
  • Sealing around timber windows for draught/heat control
  • Layered curtains to reduce radiant heat off glass

Melbourne may be cold now but it’ll get hotter. You’ll feel the biggest difference when you stack solutions:shade the glass, seal the gaps, ventilate at the right times and upgrade the glazing. Done together, these steps turn punishing afternoons into manageable ones and help nights feel like nights again. If you’re navigating heritage or strata constraints,retrofit double glazing windowsoffer a practical, low-disruption path to cooler, quieter, more comfortable rooms for summer and beyond.

If you’d like guidance on which rooms to prioritise or how to pair glazing with shading for your specific orientation, alocal Magnetite specialistcan assess your windows and map a staged plan that fits your home, budget and timeline.

  1. Conduction
    Heat moving through an object (i.e. heat will travel through an aluminium, or steel frame more easily than through a timber or PVC frame).
  2. Radiant heat
    Heat from the direct sun. It can pass through space until reflected or absorbed.
  3. Convection
    Heat flow resulting from air movement e.g. either 'natural' convection - warm air rises, or 'forced' convection - a breeze by a window, both can result in a draught by a window.
  4. Infiltration
    Air leaks around the frame, around the window sash and through the gaps in the movable window parts.

When evaluating your options to improve the thermal performance of your windows, the following double glazing key performance criteria should be considered:

  • U-Value (Uw) represents heat transfer through a window, irrespective of direct sunlight. The lower a window’s U-Value, the better the insulation performance.
  • Solar Heat Gain Coefficient (SHGC) measures the solar energy that passes through glazing. The lower the SHGC, the less solar heat is transmitted through a window.
  • Air Infiltration or leakage measures the rate at which air passes through gaps in window joins and seals. The lower the air infiltration, the better a window’s energy performance.

The Window Energy Rating Scheme (WERS) Thermal Performance

Aluminium Frame Windows

Glazing Type Cooling Stars Heating Stars Cool% Heat% Uw SHGC
Single glazed 3mm clear glass* half blue star red starhalf red star 7.4 0.77
Single glazed 3mm clear glass &
4.5mm Magnetite
blue starblue starhalf blue star red starred starred starred starred starhalf red star 35% 59% 2.9 0.67

Timber Frame Windows

Glazing Type Cooling Stars Heating Stars Cool% Heat% Uw SHGC
Single glazed 3mm clear glass* blue starhalf blue star red starred starred starhalf red star 20% 28% 5.5 0.69
Single glazed 3mm clear glass &
4.5mm Magnetite
blue starblue starhalf blue star red starred starred starred starred starred star 37% 61% 2.6 0.66
Single glazed 3mm clear glass with
Solartite** and 4.5mm Magnetite
blue starblue starblue starblue starblue starblue starhalf blue star red starred starred starred starhalf red star 76% 45% 1.8 0.20

 

*WERS standard typical industry window
**Solartite is a range of high performance window film. The window tested above has Solartite’s low-e film.


Magnetite vs Traditional Double Glazing – What the experts says

Winter - the ideal situation is to let in as much of the sun's heat and then trap it inside to maintain a comfortable environment in your home or office. This will also significantly reduce heating costs and saves you money. The ideal window for winter will have a high SHGC to let the sun's heat in and a low U-Value to prevent the heat from escaping. Clear windows without shading films are better suited for winter climates.

Compared with traditional double-glazing, Magnetite’s double-glazing solution can provide better results during winter or for cold climate areas such as Canberra, the Adelaide Hills and Blue Mountains.

Magnetite's clear acrylic window panels allow the direct heat from the sun's rays to enter the building and once inside, Magnetite's superior magnetic seals retain the heat, giving Magnetite an advantage over conventional operating windows.

Glazing Type Cooling Stars Heating Stars Cool% Heat% Uw SHGC AI
Double Glazed 3mm clear glass/12mm air
gap/3mm clear glass IGU (Insulated Glass Unit)*
blue starblue starhalf blue star red starred starred starred starred starhalf red star 40% 55% 3.0 0.61 5.0
Single glazed 3mm clear glass &
4.5mm Magnetite
blue starblue starhalf blue star red starred starred starred starred starred star 37% 61% 2.6 0.66 0.5

 

*WERS standard typical industry window

Summer - the ideal situation is to minimize the heat coming in from outside and prevent the cool air inside from escaping through the window. This will make your home more comfortable and reduce your air-conditioning costs. The ideal window for summer, or for a large west-facing window, will have a low SHGC to limit the heat from the sun's direct rays, as well as, a low U-Value to prevent the heat in the air outside from moving through the window and warming the cool conditioned air inside. It is better to have a shading film on the first (outer) glass pane to limit the heat that enters the double glazed unit.

The combination of Magnetite retrofit double glazing and Solartite outperforms the traditional insulated glass unit for hot climate. Magnetite fit over an existing window with reflective film will give better summer heat control than a double-glazed window with supertoned glass.

The Magnetite system stops the conduction and convection of heat better than glass windows giving superior results for summer conditions. Combined with a film or a shading device, Magnetite is the ideal solution for the hot Australian conditions.

Glazing Type Cooling Stars Heating Stars Cool% Heat% Uw SHGC AI
Double Glazed 5mm Supertoned glass/6mm
air gap/5mm clear glass IGU (Insulated Glass Unit)*
blue starblue starblue starhalf blue star red starred starred starred starhalf red star 54% 425% 3.30 0.461 5.0
Single glazed 3mm glass Solartite**
and 4.5mm Magnetite
blue starblue starblue starblue starblue starhalf blue star red starred starred starred star 73% 38% 2.4 0.19 0.5

 

*WERS standard typical industry window
**Solartite is a range of high performance window film. The window tested above has Solartite’s low-e film.

Click here to view pdf version of Magnetite WERS test result.

Noise Reduction Technical Data and Results

Proven Results

Noise pollution is one the biggest problems faced in the cities today, particularly in a high-density living. Unwanted noise can be responsible for sleep loss and lack of concentration. This can lead to a deterioration of health through increased stress levels, headaches, high blood pressure and loss of hearing.

Noise penetrates windows through leaky seals or vibrations through the window structure. To reduce noise, a window should minimise air infiltration, hold enough weight to limit vibration and allow a large air cavity. This cavity, or air gap, is the key to secondary glazing.

Expert Advice:

CSIRO Research by John Davy shown an air cavity can effectively enhance sound insulation performance. The larger the air cavity the more noise the window system can reduce. Results show a wide air gap of 100-125mm will improve sound insulation by an average of 7dB(A) more than windows with a narrow gap of 8-13mm.

Window or Glass Door Type Total Glass Thickness (mm) Air Cavity Thickness (mm) Sound Insulation (dB)
Single Glaze 3mm 3 0 23
Single Glaze 6mm 6 0 27
Double Glaze Narrow Gap 9-12 8-13 31
Double Glaze Wide Gap 9-12 100-125 38

 

The human ear is less sensitive to low frequency sound. According to a study released by the CSIRO, the human ear needs a change of 3dB to detect a difference in noise levels and the human ear perceives a change of 10dB as a doubling or halving of the noise level.

If you double the thickness of glass in a window the noise level will decrease by 3dB the least amount possible to make a difference. If the glass is laminated there is no perceived difference in noise reduction.

National Acoustic Laboratory Testing:

Working with the principles of noise transfer, Magnetite® and Soundtite are designed for high performance, which is achieved by combining air tight seals with the ability to maximize an air cavity and the flexibility to vary glazing thickness to suit. Magnetite® is excellent at reducing general noise such as busy roads, commuter trains and noisy neighbours. Whereas, Soundtite works well to combat low frequencies noise such as garbage truck, freight trains or airplane during take-off and landing.

Test Code Material Tested Rw* Improvement
ATF 707 (test window) Aluminium sliding window, 3mm float glass with mohair seals 23 N/A
ATF 709 Test window, 100mm air gap and Magnetite System (4.5mm acrylic panel) 35 52%
ATF 1507 Test window, 100mm air gap and Magnetite System (10.0mm acrylic panel) 39 70%
ATF 817 Test window, 100mm air gap and Soundtite (6.38mm laminated glass) 41 78%

 

*The Weighted Sound Reduction Index (Rw) is a measure for sound insulation performance of a single building element such as windows. The higher the Rw rating, the better the sound insulation.