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 hardware products  can compromise window and door security, increasing the risk of break-ins and putting residents at risk.
• Corrosion failures: Poorly finished hardware corrodes more rapidly in salt-air environments.  This can lead to jammed doors, seized hinges, water ingress and dulled aesthetics.
• Noise complaints in urban sites: Under-performing  acoustic ventilation products fail to attenuate external noise resulting in occupant dissatisfaction 

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

6 tests hardware suppliers should pass with ease 

1. Do they have robust Product Testing & Certifications?

Don’t take suppliers at their word – demand evidence.

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 do 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 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.

3. 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 acoustic ratings.
• Site support and troubleshooting assistance during installations (and post sale etc).

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

4. 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 stock availability for fast replacements.

5. Do they have their own production facilities?

If you care about quality assurance, start by looking at where—and how—your supplier builds their products.

When window and door hardware is critical to final handover, QA shouldn’t stop at a product label. It needs to be woven into the entire production process. That’s why working with suppliers who operate their own manufacturing facilities—especially UK-based ones—can make all the difference between dependable supply and frustrating rework.

As a pre-construction lead juggling specifications, timelines and tight client expectations, you need hardware partners who are as detail-oriented as you are. Suppliers with direct control over production are better positioned to:

• Maintain consistent quality across batches, with in-house QA checks embedded at each stage.

• Prove compliance more easily, with traceable testing to EN, PAS or BS standards.

• React faster to late-stage changes, such as spec upgrades or batch variations across plot types.

• Deliver on time, thanks to tighter planning and fewer dependencies on international supply chains.

You’re not just buying hinges or trickle vents—you’re buying reliability. And if your supplier is outsourcing to anonymous factories abroad, your QA risks start rising fast.

When vetting hardware suppliers, ask:

• Do they own and manage their own production line, or is it fully outsourced?

• Is manufacturing UK-based to support short lead times, sustainable sourcing, and UK regulation alignment?

• What QA systems are in place on the shop floor—are they ISO 9001 certified?

• Can they handle project-specific requirements like phased deliveries or custom-finished variants?

• Are their testing facilities in-house, and do they share data on durability, corrosion resistance or cycle testing?

6. Do they have a complete bought-in product (BIP) 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.

Case study - ensuring hardware quality through 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’ .  Stringent testing ensures the quality of bought-in products which Titon can confidently pass on reliable products and components to its suppliers and ultimately to its customers. 

But it doesn’t stop there.  Titon also has a dedicated Far East Product Engineering team 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. Titon ensures continuous oversight and feedback throughout the entire process, from initial product specification (pre-build and post-build) and in-factory quality assurance to final testing at the Area 24 facility. 

Look inside Titon's AREA 24:

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
• Understand regulations and offer technical guidance.
• Support you with warranties and fast replacements when issues arise
• Maintain oversight of offshore manufacturing.