How to Stop Your Home Overheating in Summer: The Glazing Guide (2026)

2. Why Is My Home Getting So Hot at Night?

Warmer summers expose a critical weakness in modern UK home design. If you observe the traditional architecture of properties in naturally hot Mediterranean countries, their windows are typically small and deeply recessed, particularly on south-facing elevations.

Rewind to the UK, and we do the exact polar opposite. South-facing gardens are highly prized by house buyers. Rather than minimizing the glass on the south side to block the sun, we install massive bi-fold doors and wide conservatories to maximize the view. Consequently, on hot days, our homes act like massive greenhouses, absorbing huge amounts of solar heat.

This is compounded heavily in denser urban areas (like central Basingstoke or Southampton) where heat is absorbed into pavements, roads, and masonry during the day. It is then slowly released back into the atmosphere at night, keeping ambient temperatures high and making sleeping incredibly uncomfortable.

3. Immediate Actions (The “Open Window” Myth)

If you are currently sweltering, your first instinct is likely to throw every window in the house wide open. This is often a massive mistake.

To stop the heat rising in your home, you must adopt the “Mediterranean Method”:

• Keep Windows Closed: During peak daytime heat, shut your windows tight to trap the cooler, shaded air inside.
• Close the Curtains/Blinds: Prevent direct sunlight from hitting your floors and furniture, as these objects absorb radiation and turn into internal radiators.
• Night-Purge Ventilation: Wait until the sun goes down and the outside temperature finally drops below your indoor temperature. Then open windows on opposite sides of the house to create a rapid through-draught of cooler night air.

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Night-purge cross-ventilation: Open windows on opposite sides of the home only when the outside temperature has dropped.

4. The Science: U-Values vs. G-Values

Glass is singularly the most highly technical aspect of modern window design. When purchasing new windows, you cannot simply look at a generic “Window Energy Rating” (WER) and assume it will keep you cool. In fact, a window designed specifically to keep your house warm in the winter might be the very thing cooking you in the summer.

5. How Solar Control Glass Works

If you intend to use a large amount of glass on the South or West facing aspect of your property, you absolutely must consider specifying Solar Control Glass (also referred to as anti-sun or reflective glass).

This high-performance glass features microscopically thin, virtually invisible metallic coatings applied directly to the surface during manufacturing. It keeps your home cool by precisely manipulating three specific factors of solar radiation:

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Solar control glass actively reflects invisible infrared heat radiation while allowing natural visible light to pass through.

The Result: While standard double glazing might have a G-Value of 0.70 (allowing 70% of the sun’s heat inside), premium solar control glazing can achieve a G-value as incredibly low as 0.18. This means less than a quarter of the sun’s heat makes it into your living space, rendering your conservatory or kitchen extension perfectly usable, even on the hottest day of the year.

6. Frequently Asked Questions