Part Q: What it means for your home extension

Category: Buying Guide / Regulations
Reading Time: 5 Minutes

Installing PAS 24 compliant windows on an extension adds peace of mind.

Building an extension or a new home is exciting, but the paperwork can be overwhelming. One regulation that often catches homeowners out is Approved Document Q (Security).

Introduced in 2015, Part Q was designed to ensure new homes are built to resist intruders. But does it apply if you are just building an extension? At KJM Group, we believe you should know exactly what you are paying for—and why “optional” security is usually the smarter choice.

1. What is Approved Document Q?

Approved Document Q is the section of the UK Building Regulations that deals with “Security in Dwellings.” It mandates that all easily accessible windows and doors (ground floor, or accessible via a flat roof) must be robust enough to resist physical attack by a burglar.

2. Does it Apply to Me?

This is the most common question we get at KJM. The rules differ depending on whether you are building new or replacing old.

3. The Specs: What makes a window “Part Q”?

A standard double-glazed window might look the same as a Part Q compliant one, but physically, they are very different. To achieve the PAS 24 standard required by Part Q, the unit usually needs:

• P1A Laminated Glass: At least one pane of glass must be laminated (like a car windscreen). If a burglar smashes it, it holds together rather than shattering.
• Security Clips: The glass must be bonded or clipped to the frame so it cannot be removed from the outside.
• Key Locking Handles: All accessible openings must be lockable.
• Meeting Rails: On french doors or windows, the central meeting point must be reinforced to prevent jemmying.

4. Official Government Downloads

For the full technical details, you can download the official government Approved Documents here.

5. Frequently Asked Questions