Avoid Costly Mistakes with These Insider Tips
Buying double glazed windows is a big decision for many Perth homeowners, and not all products or quotes offer the same value. A practical checklist can help you compare quality, understand double glazing cost, and avoid common mistakes before you commit. From frame materials to installation details, knowing what to ask upfront can make the buying process much easier. Whether you are replacing windows throughout your entire home or upgrading key rooms, investing time in proper research and comparison protects you from expensive regrets.
Why a Checklist Matters Before You Buy Double Glazed Windows
Double glazing represents a significant investment that affects your home for decades. Unlike smaller purchases you can easily replace if they disappoint, windows become permanent fixtures that influence comfort, energy costs, security, and property value. Making the wrong choice means living with underperforming products, dealing with premature failures, or facing expensive replacements far sooner than expected.
The challenge is that double glazing options vary enormously in quality, performance, and value. Surface-level sales claims can sound impressive without revealing important details about materials, construction, or what happens after installation. Without a structured approach to comparing options, it is easy to focus on price alone or be swayed by persuasive marketing rather than genuine product quality.
A practical checklist helps you ask the right questions, compare quotes accurately, identify quality differences, and make confident decisions based on facts rather than assumptions.
1. Check the Type of Double Glazing Being Offered
Not all double glazing is created equal. The term “double glazed” simply means two panes of glass with a gap between them, but this reveals nothing about glass quality, cavity width, gas fill, coatings, or overall performance. Significant differences exist between basic double glazing and properly specified high-performance systems.
What to ask:
- What is the glass thickness for each pane?
- What is the cavity width between the panes?
- Is the cavity filled with air or argon gas? (Argon provides better insulation)
- Does the glass have Low-E (low-emissivity) coatings to reduce heat transfer?
- Is toughened or laminated safety glass used where required?
- What is the overall U-value or thermal performance rating?
Understanding these specifications helps you compare genuine performance rather than accepting generic “double glazed” claims. Better specifications cost more but deliver measurably superior thermal comfort, energy efficiency, and noise reduction.
2. Compare Frame Materials Carefully
The frame material significantly affects durability, thermal performance, maintenance requirements, and appearance. In Perth’s harsh climate with intense UV exposure, high temperatures, and salt air in coastal areas, frame quality matters for long-term satisfaction.
Aluminium frames dominate Perth’s quality double glazing market for good reason. They offer excellent structural strength for large panels, resist corrosion when properly finished, maintain appearance with minimal maintenance, and suit contemporary architectural styles. However, standard aluminium conducts heat, which is why thermally broken aluminium frames are essential for Perth conditions. The thermal break interrupts heat transfer through the frame, significantly improving energy efficiency.
uPVC frames provide good thermal insulation naturally and resist corrosion without special treatment. However, they are bulkier than aluminium, offer fewer colour options, and can degrade in extreme heat if not properly formulated for Australian conditions.
What to check:
- Is aluminium thermally broken? (Essential for thermal performance in Perth)
- Is uPVC formulated and certified for Australian conditions?
- What powder coating or finish protects against UV and corrosion?
- How thick are the frame profiles?
- What colour and finish options suit your home’s style?
Browse our full range of colours and finishes to see what is available, or speak with our team if you are weighing up frame materials for your Perth home.
3. Ask What Is Included in the Quote
Quote comparison becomes meaningless when different suppliers include different scope. A quote that appears cheaper might exclude critical elements included in higher quotes, making accurate comparison impossible without careful review.
Essential inclusions to verify:
- Product supply: Exact window specifications, sizes, and quantities
- Delivery: Transport to site and handling
- Removal: Removal and disposal of existing windows
- Installation: Labour, fixings, sealing, and weatherproofing
- Finishing: Internal and external trimming, painting touch-ups, or render repairs
- Clean-up: Site cleaning and rubbish removal
- Compliance: Building approval documentation if required
Red flags to watch for:
- Vague line items without clear scope description
- “Supply only” quotes compared against full installation quotes
- No mention of old window removal or finishing work
- Unclear responsibility for building approvals or compliance
Always request written clarification of scope before comparing prices. What appears to be a bargain quote often becomes expensive once all necessary work is properly included.
4. Look Beyond the Lowest Double Glazing Cost
The cheapest quote rarely delivers the best value when you consider product quality, installation standards, and long-term performance. Understanding what influences double glazing cost helps you assess whether pricing reflects genuine value or cut corners and inferior components.
What typically affects double glazing cost:
- Window size and quantity: Larger windows and more units increase costs proportionally
- Frame material and quality: Thermally broken aluminium costs more than basic frames but performs better
- Glass specification: Low-E coatings, argon fill, laminated glass, and toughened safety glass add cost but deliver superior performance
- Hardware quality: Premium locks, smooth-operating mechanisms, and durable handles cost more but provide better security and longevity
- Installation complexity: Structural modifications, difficult access, or custom sizing increase labour costs
- Supplier overhead: Established businesses with proper insurance, warranties, and support structures have higher costs than operators who may not be around in five years
Better questions than “what is the cheapest?”:
- What specifications justify this price level?
- How does this compare to higher-priced options in actual performance?
- What is the expected lifespan and warranty coverage?
- What compromises does this price involve compared to premium options?
Get in touch if you would like help comparing your double glazing options.
5. Review the Quality of the Hardware and Finishes
Locks, handles, rollers, hinges, and seals determine how windows operate daily and how long they last. Inferior hardware creates frustration through difficult operation, premature failure, and security vulnerabilities.
What to check:
- Locking mechanisms: Multi-point locking provides better security than simple catches
- Operating hardware: Handles, rollers, or hinges should operate smoothly and feel substantial, not flimsy
- Seals and weatherstripping: Quality seals maintain their shape and effectiveness over time
- Finish quality: Powder coating should be even, durable, and resistant to Perth’s UV exposure
- Sample inspection: Request to see and operate physical samples, not just brochures
Warning signs:
- Thin, lightweight frames that flex when handled
- Locks or handles that feel cheap or operate roughly
- No opportunity to inspect physical samples before committing
- Generic “quality hardware” claims without specific details
Insist on seeing and operating samples of the actual products being quoted. How they feel in use reveals quality differences that specifications alone cannot convey.
6. Understand the Installation Process
Even premium windows underperform when poorly installed. Gaps, misalignment, inadequate sealing, or structural damage during installation all compromise performance regardless of product quality. Understanding the installation process helps you assess whether the supplier has the expertise to install properly.
Essential questions:
- Who performs the installation? (In-house teams or subcontractors?)
- What qualifications and experience do installers have?
- How long does installation typically take?
- What site preparation is required?
- How are windows secured, sealed, and weatherproofed?
- What happens if structural issues are discovered during installation?
- How is the site protected during work and cleaned afterward?
In-house installation teams generally deliver more consistent results than subcontractors because they represent the supplier directly and follow established procedures. Penot Double Glazing handles all installations in-house for exactly this reason. Learn more about our process.
Installation red flags:
- No clear information about who installs or their experience
- Unrealistic installation timeframes that suggest rushed work
- No discussion of site preparation or protection
- Vague answers about installation methods or quality control
7. Ask About Warranties and After-Sales Support
Warranties protect your investment and provide recourse if problems develop. However, warranty value depends entirely on coverage scope, duration, and the supplier’s ability to honour claims years after installation.
What to verify:
- Product warranty: What components are covered and for how long? (Frames, glass, hardware, seals)
- Installation warranty: What installation-related issues are covered?
- Warranty duration: Industry-leading suppliers offer 10-year warranties on frames
- Claim process: How do you make warranty claims? What response time is guaranteed?
- Supplier stability: Will the supplier still exist to honour warranties in 10-15 years?
After-sales support matters too. Look for adjustment services if windows need fine-tuning after installation, spare parts availability for hardware or seal replacement, responsive service when issues arise, and a local presence you can actually reach. Read what our customers say about their experience on our testimonials page.
8. Consider How the Windows Will Perform in Daily Life
Technical specifications matter, but ultimately your windows need to make your home more comfortable, secure, and pleasant to live in. Thinking beyond showroom appearance to actual daily use helps ensure you choose products that deliver genuine improvements.
Practical considerations:
- Thermal comfort: Will these windows make rooms genuinely more comfortable in Perth’s heat? See our thermal comfort page.
- Noise reduction: If traffic or neighbourhood noise bothers you, will these specifications help? See our noise reduction page.
- Ventilation: Can windows open enough for fresh air when you want it?
- Ease of operation: Can all family members operate windows easily and safely?
- Maintenance: What upkeep do these windows require over time?
- Visual impact: Do they suit your home’s architectural style?
Match window specifications to room requirements. Bedrooms might prioritise noise reduction and security. Living areas might emphasise thermal comfort and large opening sizes. Home offices might need both noise control and ventilation flexibility. Tailoring choices to specific rooms gives better outcomes than applying one specification throughout.
9. Watch for Common Red Flags
Certain warning signs indicate suppliers you should avoid regardless of their pricing or promises.
- Vague or incomplete quotes without specific product details, clear scope, or itemised pricing suggest the supplier wants to change terms later or does not know what they are quoting.
- Unclear specifications that use generic language like “premium double glazing” without detailing glass types, frame materials, or performance ratings.
- Pressure selling tactics that emphasise “today only” discounts, create artificial urgency, or discourage you from comparing other options.
- No installation detail about who installs, their qualifications, or installation methods.
- Unrealistic claims about performance, savings, or noise reduction that sound too good to be true.
- No physical samples or reluctance to show you actual products before you commit.
- Unclear warranty terms or unwillingness to provide written warranty documentation.
- No local presence or established business history in Perth.
Reputable suppliers welcome questions, provide detailed information, allow time for consideration, and stand behind their products. Check our completed projects to see the standard of work you can expect from Penot.
10. Final Checklist Before You Commit
Before signing contracts or paying deposits, verify you can confidently answer yes to these questions:
- Product specifications confirmed: Do I understand exactly what glass, frames, and hardware I am getting?
- Frame material chosen: Have I selected frame materials appropriate for Perth conditions?
- Quote inclusions checked: Do I know precisely what is included in the quoted price?
- Installation process explained: Do I understand who installs, how, and what to expect?
- Warranty reviewed: Have I read and understood the written warranty terms?
- Costs compared fairly: Have I compared like-for-like quotes including all necessary work?
- Suitability considered: Will these products actually improve my daily living experience?
- Supplier researched: Is this an established, reputable Perth business I can trust?
- Timeline understood: Do I know when installation happens and how long it takes?
- Questions answered: Has the supplier addressed all my concerns satisfactorily?
If you cannot confidently answer yes to all of these, you need more information before proceeding. Reluctance to provide clear answers is itself a warning sign.
How to Choose the Right Double Glazing for Your Perth Home
There is no one-size-fits-all answer. The best solution depends on your specific home, budget, priorities, and performance requirements. What works perfectly for a coastal property facing traffic noise might be overkill for a quiet suburban home or insufficient for a large luxury build.
The key is matching products to your actual needs rather than defaulting to the cheapest option or being oversold features you will not use. Take time to visit showrooms, see and operate samples, ask detailed questions, and compare multiple quotes with full scope understanding. Check our service areas to confirm we cover your suburb, then request a free quote to get started.
Get Advice Before You Buy
At Penot Double Glazing, we provide detailed product information, clear quotes with full scope transparency, and honest advice to help Perth homeowners make confident decisions. Our thermally broken aluminium windows and doors are engineered for Western Australian conditions, and our in-house installation teams ensure quality results that last.
Whether you are starting your research, comparing quotes from multiple suppliers, or ready to proceed, contact us for tailored advice before choosing your double glazed windows. We will help you understand your options, compare specifications properly, and select products that deliver genuine value for your Perth home.
Frequently Asked Questions
What should I check before buying double glazed windows?
Review glazing specifications (glass types, cavity width, gas fill, coatings), frame material quality and thermal performance, quote inclusions and scope, installation process and installer qualifications, warranty details and duration, and overall suitability for your home and Perth conditions. Use the checklist above to make sure you cover all essential factors before committing.
What affects double glazing cost?
Double glazing cost usually depends on window size and quantity, frame material quality (thermally broken aluminium costs more than basic frames), glazing specifications (Low-E coatings, argon fill, laminated glass all add cost), hardware quality, installation complexity, and supplier reputation and warranty coverage. Understanding these factors helps you assess whether pricing represents good value. See our cost savings page for more context on long-term value.
Is the cheapest double glazing quote the best option?
Not usually. Lower quotes may exclude important scope elements, use inferior materials, subcontract installation to unknown parties, or provide minimal warranty coverage. The cheapest option often involves compromises that reduce long-term value, comfort, and durability. Compare total value over the product’s lifespan rather than focusing solely on upfront price.
Does installation quality really matter?
Yes. Even premium windows underperform when poorly installed. Gaps, misalignment, inadequate sealing, or structural damage during installation compromise thermal performance, weather resistance, and longevity regardless of product quality. Always verify who installs, their qualifications, and their installation methods before committing.
How long should double glazed windows last in Perth?
Quality double glazed windows with thermally broken aluminium frames should last 30 to 45 years in Perth conditions when properly installed and maintained. uPVC windows typically last 25 to 35 years. Lifespan depends heavily on material quality, manufacturing standards, installation quality, and maintenance. Inferior products or poor installation can lead to premature failure, requiring expensive replacement far sooner than expected.
Discover more about Penot Double Glazing’s approach to quality windows and doors for Perth homes. Explore our full range of double glazed windows and doors designed for Western Australian conditions, or visit our why double glazing page to learn more about the benefits.
