What is Document Q and what does it mean for your build?
Document Q is the latest addition to the Building Regulations and seeks to bring security to the forefront by setting out reasonable standards for doors and windows in all new residences.
When does it come into force?
Work which passed planning approval prior to 1st Oct 2015 is unaffected as long as work starts before 1st Oct 2016.
All new build work commencing after 1st October 2016 will be subject to Doc Q regardless of when planning approval was granted.
What Does it Mean to Us?
Document Q affects all windows and doors in new dwellings, situated less than 2 metres vertically from an accessible level surface (such as the ground, or an access balcony). An accessible level surface could include a flat or sloping roof with a pitch of less than 30°, but not an enclosed balcony. A new dwelling includes those created through a change of use, such as barn conversions and conversions of offices and other workspaces into flats.
Affected Fenestration will need to achieve Secured by Design (PAS24:2016 or similar) status, by having their products monitored and tested by a UK Accredited Service (UKAS) accreditation test house. In order to gain certification, a manufactured product (eg Bi-Folding door), including all of its glazing and locking components, needs to be tested and approved as a whole – not just the individual components.
Fabricators (window and door manufacturers) can tier down from their profile supplier providing the profile supplier has tested the entire system and the fabricator uses only parts specified by the profile supplier.
What are the Common Requirements?
In real terms this means using 6.8mm laminated glass as opposed to toughened glass in all affected door systems and in affected opening windows without a key lockable handle. Laminated glass consists of two outer sheets of float glass sandwiching a Poly Vinyl Butyrol (PVB) interlayer (see fig. 1). Whilst this construction allows the glass to crack upon impact, the PVB layer holds the glass in position (See fig. 2) – a more secure construction than toughened glass (float glass hardened through heat soaking to approx. 620°) which, whilst more difficult to break, will eventually shatter into small harmless pieces – providing an easier and safer point of entry for intruders.
In addition to the above; letter boxes should be specified with an aperture no greater than 260mm x 40mm and main entrance doors should have a ‘spy hole’ or similar means of viewing callers.
Fig. 2 – Laminated glass after impact
Fig. 3 – Toughened Glass after impact