Do you feel like you’re throwing money away on your power bill?
If your power bill seems higher every winter, your windows could be a major reason why. Retrofit Double Glazing may be your saviour.
Many New Zealand homes were built with single-glazed windows, which allow heat to escape easily. While homeowners often focus on insulation, heat pumps, and heating costs, windows are frequently the weakest point in a home’s thermal envelope.
According to New Zealand’s Energy Efficiency and Conservation Authority (EECA), up to 30% of a home’s heating energy can be lost through windows. In older, poorly insulated homes, that number can be even higher, especially during colder regions of winter. Double glazing can significantly reduce that heat loss, helping homes stay warmer for longer and reducing the need for constant heating.
What That Means in Real Money
For many New Zealand households, winter electricity bills typically range from $200 to $400+ per month, depending on home size, insulation, and heating usage.
If up to 30% of heating energy is being lost through windows, that can translate to roughly $50 to $120 per month in wasted heating costs during winter in many average homes. Over a 4–5 month heating season, that adds up!
In colder parts of New Zealand, older or larger homes, the impact can be even higher.
How Double Glazing Works
Double glazing uses two panes of glass separated by an insulating gap. This gap acts as a thermal barrier, slowing the transfer of heat from inside your home to the outside environment.
The result is:
- A warmer home during winter
- Reduced condensation on windows
- Lower heating and cooling costs
- Improved comfort throughout the year
- Less reliance on heat pumps and heaters
The New Zealand Building Code now requires double glazing in new homes because of its proven energy-efficiency benefits. What what about the older homes?
The Real Cost of Single Glazing
Think about it this way: every dollar spent heating your home is working harder when heat is constantly escaping through single-pane glass. That means your heater may be running longer and using significantly more electricity just to maintain a comfortable temperature—especially on cold, damp winter nights.
Over time, this inefficiency doesn’t just affect comfort—it directly impacts household budgets. No, Thanks!
More Than Just Lower Power Bills
While energy savings are important, and helping your wallet, most homeowners notice the comfort benefits first.
Double glazing helps:
- Eliminate cold spots near windows
- Reduce drafts
- Minimise condensation and moisture issues
- Create a drier, healthier living environment
- Reduce outside noise
Many homeowners report that their homes feel warmer almost immediately, even before they notice changes in their power bills.
Double Glazing also helps your home stay cooler in summer, and depending on the room, help with direct sun damaging furniture and carpet.
Is Double Glazing Worth It?
Every home is different, but one fact remains consistent: windows are one of the largest sources of heat loss in New Zealand homes.
By upgrading to double glazing, you’re not just investing in lower power bills—you’re investing in a warmer, healthier, more comfortable home that retains heat far more effectively throughout winter.
If you’re tired of watching your heating dollars disappear through your windows, double glazing could be one of the most effective long-term upgrades you can make.
Contact us for a free measure & quote.
