Why QA counts: How to Choose A Reliable Window and Door Hardware Supplier

Cutting corners never pays. When hardware fails - whether through corrosion, mechanical breakdown, or security vulnerabilities - it can trigger expensive remedial work and damage relationships with clients.

This post explores the testing regimes and supplier checks you should demand from your hardware suppliers to safeguard your projects and protect future revenue.

The real-world impact of poor-quality hardware

Substandard hardware doesn't just harm your bottom line - it can directly impact building occupants and public safety:

• Security vulnerabilities: Weak or poorly manufactured locks and handles can compromise window and door security, increasing the risk of break-ins and putting residents at risk.
• Corrosion failures in coastal developments: Poorly treated or plated hardware rusts rapidly in salt-air environments, leading to jammed doors, seized hinges, and water ingress within months.
• Noise complaints in urban sites: Unreliable acoustic ventilation products fail to attenuate external noise, resulting in occupant dissatisfaction and potential legal disputes

But behind every failed lock, handle, hinge, or vent can lie a deeper issue: insufficient product testing and weak supply chain oversight.

So, to avoid compliance breaches or future legal action by clients and end customers, make sure you partner with hardware suppliers who prioritise product testing, quality control, and regulatory expertise.

Here are 5 checks you should make to ensure your supplier can guarantee levels of quality throughout your project life-cycle.

5 tests hardware suppliers should pass with ease 

1. Do they have robust Product Testing & Certifications?

Trusted suppliers should have gained ISO 9001 accreditation as an organisation and provide proof that their products meet key industry standards, including:

Mechanical durability: 

• BS EN 13126 series (for window and door hardware components, including friction stays, handles, and hinges).
• BS EN 1906 (lever handles and knob furniture).
• BS EN 1935 (door hinges)
• BS EN 12209 (locks and latches)
• Corrosion resistance: BS EN 1670, Grade 4 or 5 – particularly important for exposed and coastal sites.

Security compliance:

• PAS 24 certification for doors and windows, meeting Part Q of the Building Regulations.

Acoustic ventilation:

• Ensure products are rigorously tested for sound insulation and airflow efficiency. Verify that they meet relevant standards and regulations, such as compliance with Approved Document F (Ventilation).

What to look for:

• In-house product testing facilities or partnerships with third-party testing labs. 
• Pre-market product validation, including salt spray corrosion testing, mechanical load assessments, and lifecycle performance testing.
• Transparency about testing processes and product performance certifications.

2. Do they have a complete bought-in product (BIP) QA process?

How well does your supplier manage their offshore supply chain?

Many hardware suppliers outsource manufacturing overseas, but the best suppliers implement strict quality controls throughout the supply chain to prevent substandard products from reaching the site.

Key questions to ask suppliers:

• How do you audit your overseas manufacturers?
• Are imported products batch-tested upon arrival in the UK?
• What action is taken if a product fails quality checks?

What to look for:

• Engage suppliers who have dedicated product engineers in manufacturing regions to oversee production quality.
• Ensure that products undergo final-stage testing in the UK before delivery to fabricators or sites.
• Insist on traceability—the ability to track product batches from manufacture to installation.

3. Do they have a proven track record on large-scale & multi-phase projects?

Can your supplier deliver consistently at scale?

Hardware suppliers should be able to demonstrate their capability to supply large orders across multi-phase projects without dips in quality or disruptions in delivery schedules.

What to check:

• References and case studies from developers, fabricators, or housebuilders.
• Evidence of long-term supply agreements with partners on multi-phase residential or commercial developments.
• Supplier ability to meet deadlines during peak demand periods.

4. Do they offer regulatory insight & technical support?

Does your supplier understand the latest UK Building Regulations?

Compliance is non-negotiable. Suppliers should be well-versed in the regulatory landscape and capable of guiding you through the requirements for:

• Part L: Energy efficiency and airtightness standards.
• Part F: Ventilation requirements.
• Part O: Overheating risk mitigation.
• PAS 24 / Part Q: Security standards for doors and windows.
• Future Buildings Standard (2025): Stricter thermal and low-carbon performance standards.

Support to expect:

• Early-stage design advice to ensure hardware choices align with regulatory requirements.
• Product performance data available upfront, including u-values and acoustic ratings.
• Site support and troubleshooting assistance during installations.

Suppliers offering BPEC-certified advisors or CPD training sessions can add further value, helping your teams stay ahead of regulatory changes.

5. Do they offer the right warranty & aftercare support?

What’s your supplier’s response when things go wrong?

Even with rigorous testing, occasional product issues are inevitable. Your supplier’s warranty coverage and aftercare support can make or break your response time when defects arise.

What to clarify:

• Warranty periods: Are they competitive within the market?
• Claim processes: Are they clear, and is the supplier responsive?
• Replacement services: How quickly can defective hardware be swapped out?
• UK-based support teams: Are technical experts available to attend the site if needed?

The best suppliers:

• Prioritise rapid resolution of product issues to prevent costly delays.
• Offer clear warranties on both hardware and ventilation products.
• Have local stock availability for fast replacements.

Case study - ensuring hardware quality with an ‘end-to-end approach 

The hardware supplier Titon has developed an industry-leading approach to testing products, including its state-of-the-art testing and quality control facility,  Area 24.

Look inside Titon's AREA 24:

But it doesn’t stop there. Titon also has a dedicated Far East Product Engineering Manager who bridges the gap between the UK headquarters and its international supply chain, ensuring its approach to quality is never compromised. 

Not every hardware business maintains such a direct, on-the-ground relationship with its overseas suppliers.

The bottom line: avoid false economies

Simply choosing the cheapest supplier can end up costing the most in the long run. Hardware failures lead to installation delays, compliance issues, post-handover callbacks, and reputation damage.

Here’s what the most reliable suppliers do differently:

• Test rigorously before products reach the site
• Maintain oversight of offshore manufacturing.
• Understand regulations and offer technical guidance.
• Deliver consistently on multi-phase projects.
• Support you with warranties and fast replacements when issues arise

When it comes to window and door hardware, quality assurance is not just a cost - it’s your safeguard against future project failure.