What Is Regulation 4 (Reg 4)?
Reg 4 requires that every water fitting used in a plumbing system must be:
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Of an appropriate quality and standard
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Suitable for the circumstances in which it is used
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Installed correctly to prevent waste, misuse, contamination, or undue consumption
Put simply: any material or product in contact with mains water must not affect water quality or pose a health risk.
What Products Does Reg 4 Cover?
Reg 4 applies to both:
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Plumbing systems - pipework, taps, valves, flush systems
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Non-metallic components - such as rubber washers, plastics, sealants, hoses, and fittings
For interior designers, this means many of the visible and decorative elements in a luxury bathroom — such as sensor taps, thermostatic mixers, or accessible shower fittings - must be Reg 4 compliant.
Why Reg 4 Compliance Matters in Design
Failure to specify Reg 4 compliant products can result in:
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Installation rejection by water authorities or building control
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Project delays and increased costs
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Health and safety risks for end users
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Legal non-compliance for the client or property owner
In high-spec commercial projects - hotels, offices, restaurants, or leisure spaces — this level of compliance is non-negotiable. Choosing Reg 4 certified products streamlines approval and ensures peace of mind.
How Is Reg 4 Compliance Verified?
Compliance can be demonstrated through third-party testing and certification. The two most recognised routes are:
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WRAS Approval: Products tested by WRAS-accredited labs
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Kiwa Certification: Internationally recognised and accepted by UK water suppliers
At Fitzroy of London, we partner with Kiwa to test and approve our WRAS 4-compliant products - ensuring full alignment with Reg 4 while maintaining design flexibility.
What Designers Should Look for
When specifying products for bathrooms or washrooms:
- Ensure all water-contact materials are Reg 4 compliant
- Request WRAS or Kiwa certification for assurance
- Avoid mixing non-certified components in visible or critical locations
- Choose suppliers who understand both regulations and design
Our team at Fitzroy of London works with interior designers from concept to completion, ensuring every product specified is compliant, functional, and beautifully finished.
How Fitzroy of London Supports Reg 4 Compliance
We make it easy for you to meet technical standards without sacrificing creative vision:
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Kiwa-approved WRAS 4 products tested to meet Reg 4 requirements
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Fully customisable finishes - from classic to contemporary
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Technical documentation and certification provided upfront
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Expert consultation to support compliance on complex projects
Whether you're designing an inclusive hotel suite or a statement washroom in a corporate headquarters, our Reg 4-compliant bathroom products ensure you get both design integrity and legal peace of mind.
Explore Our Reg 4-Compliant Product Range
Looking for stylish bathroom components that meet the highest technical standards?
👉 Browse our certified products
👉 Speak to our team for support
