Part Q
Plain English. Practical detail. UK context.
Part Q is England's Building Regulations provision on security in dwellings. Approved Document Q provides guidance intended to resist unauthorised access through relevant doors and windows. It is not a promise that a home is burglar-proof, and a lock alone is not the complete security performance of an opening.
Last reviewed: (editorial review against the public sources listed below).
Know which dwellings the guidance covers
Approved Document Q states that its guidance applies to new dwellings, including dwellings formed by material change of use. Do not describe it simply as a universal rule for every replacement lock in every existing home. The actual work scope and other requirements still need checking. Homeowners planning a conversion or new dwelling should raise security before products are ordered. Tradespeople need the intended doorset and window specification rather than a general request for secure hardware. Existing-home improvements can be worthwhile without being identical to the document's formal application.
A complete assembly has several parts
Leaf or sash, frame, glazing, hardware, fixings and installation can influence resistance. A high-security cylinder does not automatically establish the performance of an otherwise unsuitable door and frame. The guidance includes routes using relevant product testing or specified construction details, with scope and conditions. Trainees should not mix convenient components or enlarge openings without an appropriate decision. A certification mark or product claim must be checked for the actual assembly, size and configuration. Do not transfer a test description from one product variant to every item sold under the same brand.
Security must not undermine escape or access
Fire escape, accessibility, glazing safety and ventilation can interact with the chosen arrangement. England's other Approved Documents provide relevant guidance. A locksmith or fitter should not replace safety-related hardware merely because a different lock seems stronger. A trainee needs to recognise a detail requiring supervisor or designer input. Electrical access controls can introduce further competence requirements. HSE guidance informs drilling, tools and unknown building materials during installation. The correct product is only part of the task; its support and interfaces need suitable installation too.
Homeowner records and realistic expectations
Agree the product, configuration, installation responsibility, checks, keys or controls and making good. Leave normal operating and maintenance information securely with the authorised customer. Keep relevant product and installation evidence. Prices and outcomes vary from job to job, so compare written, itemised quotations rather than relying on a typical figure. The customer should check their insurer's actual conditions where relevant. Use the correct national framework outside England. Tradespeople should state the actual scope and avoid presenting compliance as protection against every possible attack. Later changes to glazing, hardware or the frame should be assessed rather than assumed to preserve the original assembly's performance.
Frequently asked questions
Does Part Q exclude dwellings formed by conversion?
No. Its guidance expressly includes dwellings formed by a material change of use.
Does one secure lock prove the whole opening meets the design?
No. The complete assembly, support and installation matter.
Sources and further reading
Public sources and further reading. Sources checked: 8 November 2026. Consult the original for details and later changes.