Part Q: What it means for your home extension

Confused by Approved Document Q? Our expert guide explains PAS 24 security standards, the rules for new builds vs. extensions, and what you legally must install.

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Installing PAS 24 compliant windows on an extension adds total peace of mind against opportunistic burglaries.

Building a new extension or constructing a brand new home is an incredibly exciting process, but navigating the maze of UK Building Control paperwork can be overwhelming. One specific regulation that frequently catches homeowners and architects out is Approved Document Q (Security).

Introduced in 2015, Part Q was explicitly designed to ensure new homes are built robustly enough to resist opportunistic intruders. But does this strict law apply if you are just building a standard kitchen extension? At KJM Group, we believe you should know exactly what you are paying for—and understand why opting for “optional” security is usually the smartest long-term choice for your property.

1. What is Approved Document Q?

Approved Document Q is a specific section of the UK Building Regulations that legally dictates “Security in Dwellings.” It mandates that all easily accessible windows and doors (such as those on the ground floor, basement level, or accessible via a flat roof or balcony) must be robustly manufactured to resist physical attack by a burglar.

2. Does it Apply to Me? (The Legal Rules)

This is the most common source of confusion we encounter at KJM. The rules differ significantly depending on whether you are building a brand new house from scratch, or simply adding to an existing one.

3. The Specs: What Makes a Window “Part Q”?

To the naked eye, a standard double-glazed window might look exactly the same as a Part Q compliant one, but physically and structurally, they are vastly different. To achieve the stringent PAS 24 standard required by Part Q, the unit typically features:

• P1A Laminated Glass: At least one pane of the double-glazed unit must be laminated (much like a car windscreen). If a burglar strikes it with a hammer, it physically holds together rather than shattering into pieces, denying them entry.
• Security Glazing Clips: The glass must be structurally bonded or internally clipped to the frame so an intruder cannot simply pop the glass pane out from the outside.
• Key Locking Handles: All accessible openings must feature robust, key-lockable handles.
• Reinforced Meeting Rails: On French doors or dual-sash windows, the central meeting point must be heavily reinforced to prevent someone from jemmying them apart with a crowbar.

4. The Hampshire Extension Dilemma

5. Official Government Downloads

For full technical details, you can download the official government Approved Documents below to see exactly what building control inspectors look for.

6. Frequently Asked Questions