Part K explained: What architects and specifiers need to know about safety in glazing and balustrades

Part K of the Building Regulations 2010 covers protection from falling, collision and impact. It covers key areas including stairs, ramps, balconies, windows, barriers and other glazing elements.

It applies to all new buildings in England – both dwellings and other types of buildings – as well as to those undergoing a material change of use or certain extension and refurbishment projects, particularly those that involve the addition of new glazed elements. Guidance for achieving the standards is provided in Approved Document K. Similar requirements apply to other parts of the UK, and the relevant documents are:

• Wales: Approved Document K (Wales) – Protection from falling, collision and impact
• Scotland: Building standards technical handbook, section 4 – Safety
• Northern Ireland: Technical Booklet H –  Stairs, ramps, guarding and protection from impact

Part K is split into six parts:

• K1: Stairs, ladders and ramps – Sets out minimum design standards with an aim to reduce slips, trips and falls. It includes recommended dimensions, tread depth, riser height, pitch and handrail locations.
• K2: Protection from falling – Provides guidance when a floor edge, landing, roof terrace or balcony is above a certain height. It requires barriers to prevent falls and sets out height, strength and positioning requirements for guardrails and balustrades.
• K3: Vehicle barriers and loading bays –Sets out barrier requirements for spaces in commercial and industrial buildings where vehicles move close to pedestrians.
• K4: Protection against impact with glazing – Requires the use of toughened or laminated safety glass and glass manifestation markings in specific zones to reduce the risk of impact with large glass panels.
• K5 Additional provisions for glazing in buildings other than dwellings – Sets out additional requirements for impact resistance of doors, screens and partitions in schools, hospitals and other non-residential settings.
• K6: Protection against impact from and trapping by doors – Requires safety systems, including sensors, safety edges and fail safes, for doors and gates that have powered operation.

Understanding these requirements can help to reduce the risk of accidents and injuries while also supporting wider accessibility and usability objectives, making buildings safer and more comfortable for everyone.

Toughened or laminated glass is commonly specified, and all products should be tested in accordance with recognised standards such as BS EN 12600:2002 – Glass in building, pendulum test. This standard defines the testing method for impact resistance of flat glass. It uses a weighted pendulum to simulate an impact and classify glass based on its behaviour when struck.

Safe breakage is defined in BS EN 12600 section 4 and BS 6206 clause 5.3. In an impact test, a breakage is considered safe if it creates one of the following:

• A small clear opening only, with detached particles no longer than the specified maximum size.
• Disintegration with small, detached particles
• Broken glazing in separate pieces that are not sharp or pointed

Where safety glazing is not practical, alternative measures, such as protective screens, balustrades or other guarding, may be used. Large glazing panels should also feature appropriate manifestation markings to ensure visibility and reduce the risk of accidental collisions.

Part K sets out requirements for guarding to prevent falls from height and to protect building users from injury. Guarding is required wherever there is a risk of falling, including staircases, landings, balconies, roof terraces, raised platforms, and internal voids.

Approved Document K includes guarding height regulations. The minimum heights are typically:

• Dwellings: 900 mm for internal stairs and landings, 1100 mm for balconies and roof terraces
• Non-dwellings/public buildings: 1100 mm for stairs, landings and balconies

“While most design briefs call for minimal sightlines and large glazing panels, these characteristics can make compliance with Part K more complex,” Justin warns. “Issues typically arise around barrier heights, the use of frameless glass and ensuring the specified fixing methods provide the required containment,” he says. “These challenges can typically be resolved, but it requires careful design, specification and appropriate testing,” he adds.

Building control will expect evidence that all guarding elements meet the relevant load, impact and durability requirements. Justin recommends early coordination between the architect, structural engineer and glazing manufacturer: “This can help ensure that aesthetic goals are achieved without compromising safety or regulatory compliance,” he says.

Part K relies on verifiable performance, and documented test evidence is essential. Third-party testing to standards such as BS EN 12600 and BS 6180 provides assurance that glazing and barrier systems meet the necessary impact and load resistance criteria.

When specifying glazing and barrier systems, product documentation should include evidence of impact testing, structural performance data and details of any limitations or installation conditions that affect compliance. The documentation will also serve as evidence when submitting to building control for final approval.

Solarlux systems are engineered to meet the performance demands of modern architectural design, including applications where guarding, impact resistance and containment are required. Where appropriate, our glazed doors, balcony glazing, wintergardens, glass canopies and facades can be specified with tested safety glass, robust framing and barriers.

Our technical team can provide project-specific advice, test documentation and design guidance to help ensure the finished product is safe and compliant with Part K.

For more information about Solarlux glazing systems, contact our team for technical advice or specification support.