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Book an AppointmentChoosing new windows is one of the most significant investments you can make in your home. Get it right, and you improve your property’s energy efficiency, security, and curb appeal. Get it wrong, and you could be facing drafts, condensation, or costly replacements much sooner than expected.
At Nolan uPVC, we’ve helped thousands of homeowners across South Wales transform their properties. To help you navigate your project, we’ve put together this guide on the most common mistakes to avoid when buying new windows.

1. Prioritising Price Over Quality
It is tempting to go for the lowest quote, but with windows, you truly get what you pay for. Cheap windows often use inferior uPVC that can discolour over time or lower-grade hardware that becomes stiff and difficult to operate.
Investing in high-quality uPVC or aluminium frames ensures longevity. A slightly higher upfront cost usually pays for itself through lower energy bills and a longer lifespan for the product.
2. Ignoring Energy Efficiency Ratings
Not all double glazing is created equal. Many homeowners forget to check the BFRC Energy Ratings (ranging from A++ to E).
- The Mistake: Choosing a window based on looks alone without checking its thermal performance.
- The Consequence: Heat escaping during the winter, leading to higher heating costs and a less comfortable home.
Always look for 'A' rated windows as a standard to ensure your home stays warm and your carbon footprint stays low.
3. Forgetting About Ventilation
Modern windows are incredibly airtight - which is great for heat retention but can lead to condensation issues if ventilation isn't considered.
One common mistake is opting out of trickle vents. These small vents in the frame allow for a constant, controlled flow of fresh air, helping to prevent mould growth and maintain healthy indoor air quality without sacrificing security.
4. Overlooking Security Features
Windows are a primary entry point for intruders. A common error is assuming all windows offer the same level of protection. Ensure your new windows feature:
- Multi-Point Locking Systems: These systems secure the window into the frame at several points simultaneously, making it much harder to force open than a standard latch.
- Internal Glazing Beads: By placing the beads on the inside of the house, you prevent intruders from simply removing the glass from the exterior to gain entry.
- Key-Locking Handles: These provide an essential extra layer of defense, ensuring that even if the glass is compromised, the window cannot be easily unlatched.
- PAS 24 & Secured by Design: These are elite, police-approved standards for attack resistance.
5. Not Considering the Style of the Property
Installing ultra-modern, slim-line aluminium windows on a traditional period cottage can sometimes look out of place. Conversely, bulky frames can ruin the aesthetic of a contemporary home.
Take the time to consider frame colours, woodgrain finishes, and hardware styles. Whether you need classic Sash Windows or versatile Tilt and Turn options, the style should complement your home’s original character.
6. Choosing the Wrong Installer
Even the best window in the world will underperform if it isn't fitted correctly. A poor installation can lead to structural issues, water ingress, and voided warranties.
Mistakes to avoid:
- Hiring an unregulated handyman instead of a specialist company.
- Failing to check for FENSA or CERTASS certification.
- Choosing a company that doesn't offer a comprehensive 10-year guarantee.

Why Choose Nolan uPVC?
With over 30 years of experience, Nolan uPVC is dedicated to helping you avoid these pitfalls. We manufacture our own products right here in Wales, allowing us to maintain strict quality control from the factory floor to your front door.
Our expert team handles everything from the initial design and technical survey to the final installation, ensuring your new windows fit perfectly and perform for decades to come.
Ready to upgrade? Get a free quote online or contact us and our team will do their best to answer any questions you may have.

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