Why the sun effects comfort
In New Zealand the sun tracks across the northern half of the sky. That simple path explains why one side of your house may feel cosy and bright while another feels stuffy or permanently chilly. The goal is to design each façade so it collects the right kind of sun at the right time of year. Get this right and you enjoy natural warmth in winter with relief from the harshest summer glare.
How each facade behaves
North
Your northern facing facades get the longest daily exposure. Brilliant for passive warmth in winter, but they can overheat in summer without correctly sized eaves or other shade.
East
Eastern facing facades bring quick morning warmth. Great for kitchens and living spaces, but bedrooms and home offices often suffer from early glare.
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West
These facades are the hardest to manage. Low afternoon sun combines with lingering outdoor heat, so evenings can become uncomfortably warm.
South
South facing facades receive little direct sun. Light is even and soft, so comfort relies more on insulation and high-performance glass than on solar control.
The Daily Rhythm
The morning sun is gentle but low, so it hits directly through glass. By midday the sun is high and the peak is short. Afternoons are where problems start. The lower angle drives intense light and heat through west-facing windows. Over summer these hours stretch longer and feel more aggressive. In winter the shorter path means north-facing glass can become a welcome source of free heating.
A Quick Seasonal Summary
Summer
Long, high sun with harsh intensity that needs to be managed all day long. Good eaves on northern and western facades help halt overheating
Winter
Shorter days, lower angles, and valuable natural warmth to capture. Make use of your northern facade to capture sun and southern to hold in the warmth
Autumn
The sun sits lower and afternoons can stay warm, with longer low-angle west light to control while keeping pleasant daytime warmth.
Spring
The sun climbs higher again with cool mornings and quick daytime warm-up, so manage early east glare while holding onto passive gains
Two tools solve most comfort issues
Shading and glazing work in tandem. Shading decides when the sun enters. Glazing decides how much of that light becomes heat or glare. Used together they create a balance that a one-spec-fits-all approach cannot deliver.
The Winning Duet
Glazing
- Orientation-specific glass chosen for how each façade behaves
- Low-E and solar control options like our SuperTherm range to trim summer heat gain on east and west
- Higher insulation value on the south side to lift winter comfort without relying on sun
Shading
- Fixed eaves for north-facing glass to block high summer sun while allowing winter sun in
- External blinds or screens for east and west to deal with low-angle light and late heat. Having external blinds stops the heat from entering your home. Once the heat is inside, internal blinds won’t do anything to stop it.
This combination tackles the pain points Kiwi homeowners mention most: hot northwest-facing living rooms that take hours to cool, north windows that feel brilliant in July but unbearable in January, morning glare in east bedrooms, and south rooms that never seem to warm up.
Practical recommendations
- Use higher-insulation Low-E glass like Supertherm Warm on the south side to improve comfort and reduce heat loss.
- Select a solar-control Low-E glass like Supertherm Cool for east and west to cut afternoon heat gain and glare while keeping useful daylight.
- If your northern facing windows have little or no eaves, consider Supertherm Cool to soften high summer sun while keeping light. With good fixed eaves that block high sun, Supertherm Warm can help capture winter gain.
- Tune visible light transmission (VLT) per room type. Bedrooms and screens benefit from slightly lower VLT to reduce glare, living spaces can handle higher VLT for brightness.
- Where fading or noise is a concern, consider laminated or UV-Minimising glass like Supertherm Protect to lift UV rejection and add acoustic comfort.
- Match glazing to each façade and room use rather than applying one glass spec across the entire house.
Why RetroGlaze
We don’t guess. Your local RetroGLAZE® partner can provide a useful thermal report that models the sun’s seasonal path for your exact address, including the orientation of each façade and any neighbouring shading. That gives our partners the tools to recommend the right mix of shading and glass for every side of your home, not just a generic package. The result is steadier indoor temperatures, softer light, and fewer uncomfortable hot or cold zones, ensuring your glazing isn’t just installed, but that it’s fully optimised for your home’s comfort.
Book a consultation with one of our experts in your area to get your thermal report.
