Secured by Design Explained: What It Means for Your Home's Locks and Doors

You might have seen the "Secured by Design" logo on lock packaging, heard it mentioned by a builder, or seen it referenced in a planning application. But what does it actually mean? Is it a legal requirement? And should you specifically seek out SBD products when upgrading your home security?

Product accreditation belongs to an exact current listing, not to a broad brand or everything a locksmith may fit. Here is how to verify the scheme and the underlying standards without turning either into a guarantee.

What Is Secured by Design?

Secured by Design (SBD) is a police crime prevention initiative owned and managed by Police Crime Prevention Initiatives Limited (PCPI). It has been running since 1989 and works with the construction industry, product manufacturers, and developers to design out crime.

In practical terms, SBD does two things:

The Secured by Design crime-prevention handbook describes SBD as the official police security initiative. SBD accreditation is not a blanket legal requirement for existing homes. A particular project may separately have planning, building-control, contract or policy requirements, which must be checked from its own documents.

How Products Get SBD Certification

To carry the Secured by Design mark, a product must pass specific independent testing standards. The key ones for home security are:

Doors: PAS 24

PAS 24 is the enhanced security standard for doors and windows. It tests the entire doorset (door, frame, hardware, and lock together) against simulated forced entry. A door that passes PAS 24 has been tested with:

PAS 24 is one route used for doorsets seeking SBD accreditation. Approved Document Q applies its security requirement to new dwellings; it should not be treated as a blanket requirement for renovation projects or existing homes.

Cylinders: TS007 and SS312

For doors that use euro cylinders, two specifications often appear in product documentation:

TS007 — a Door & Hardware Federation technical specification for replacement cylinders and associated security hardware. Its star markings belong to the exact certified product:

SS312 Sold Secure Diamond — another accreditation that may appear on an exact cylinder. Verify the current certificate and scope rather than inferring performance from a logo, old listing or manufacturer name.

To achieve the SBD requirement for euro cylinders, you need either:

I have explained these standards in detail in my post on TS007 vs SS312 lock standards.

Mortice Locks: BS3621

For suitable traditional mortice deadlocks fitted into timber doors, BS3621 defines requirements that include resistance to specified attacks, key security and bolt performance. Certification belongs to the exact product. Some policies may name BS3621, so check the current wording; Secured by Design accreditation also belongs to listed products rather than to every product that references the standard.

Windows: PAS 24

Like doors, windows achieve SBD certification through PAS 24 testing. The entire window unit — frame, glass, hardware, and locks — is tested as a complete unit.

Other Products

SBD also certifies:

Which Products Carry the SBD Mark?

The catalogue changes as products and certifications change. Do not treat an old article or a manufacturer's brand as proof that a current product is listed.

Cylinders: Search by the exact product reference, then verify its current TS007 or SS312 evidence and its dimensions for the doorset.

Doors: Check the complete doorset listing and certificate. Accreditation of one model does not extend to every door from the same manufacturer or to a doorset assembled from different components.

Windows: Check the complete window-system listing and certificate; changing one handle or lock does not make an existing window an accredited complete system.

Mortice locks: Verify the exact product's current listing and standard marking rather than relying on the manufacturer or a generic "British Standard" description.

Check whether a specific product appears in the current catalogue on the Secured by Design website, and match the exact model and certification scope.

New-Build Requirements

Approved Document Q gives guidance on meeting the security requirement for new dwellings. It should not be paraphrased as a requirement that every door and window in every new or altered property carries SBD accreditation or one named product certificate.

A development may have project-specific planning conditions or specifications. Check the actual approval and construction documents; this article has no evidence for a general Coventry or Warwickshire frequency claim.

If you have bought a new-build home, retain the doorset and window documentation and compare it with the project's requirements. Do not replace a cylinder merely because it lacks a preferred brand name: identify its exact certification, size, projection and compatibility first.

Retrofitting SBD-Equivalent Security

An existing home is not subject to a blanket SBD retrofit requirement. Retrofitted components can have their own certification, but changing one component does not reproduce a complete PAS24 doorset or window test.

Here is how to use the standards as an evidence check without describing an untested retrofit as "SBD-equivalent":

Front Door (uPVC or Composite)

Front Door (Wooden)

Windows

Patio and French Doors

How to Check If Your Products Qualify

If you want to know whether your existing locks meet SBD standards:

If you are unsure, I can record visible markings and available product details during a visit; certification still needs to be matched to current scheme evidence. Call 024 7522 4730 to arrange a check.

Is It Worth Specifically Seeking SBD Products?

My answer: use SBD accreditation when the exact listing is relevant, while also checking fit and the underlying certification.

SBD accreditation gives you evidence that a product meets the scheme's Police Preferred Specification and holds the required independent certification. SBD accredits qualifying products; the underlying laboratory testing is carried out against the relevant standard.

A TS007, SS312, BS3621 or PAS24 claim must be checked against the exact product or complete doorset certificate. SBD then adds scheme-specific accreditation for a listed product; neither the standard nor the mark guarantees that a product is suitable, correctly sized or correctly installed at a particular home.

Where SBD certification matters most:

Where it matters less:

For a particular home, first identify the doorset and fault, then verify the exact certification and any written requirement. Do not assume that naming several standards means a product meets SBD requirements or is the right repair.

If you want advice on which products are right for your home, or you want me to check what standards your current locks meet, call me on 024 7522 4730. I am happy to inspect the lock and door and explain the relevant evidence — no sales pitch, just guidance based on what can be verified at your home.

For more on lock standards, read my posts on TS007 vs SS312 and BS3621 vs anti-snap vs smart locks. For a full security assessment of your home, start with the home security checklist.

Authoritative Sources