BS EN 81-20:2020 - Safety rules for the construction and installation of lifts. Lifts for the transport of persons and goods. Passenger and goods passenger lifts. Was introduced in 2014, it mostly defines new standards for lifts and lift cars themselves.

That said, it has a specific requirement that applies to shaft walls themselves. Please see below extract from the standard.

"5.2.1.8.2 The walls of the well shall have a mechanical strength such that when a force of 1000 N, being evenly distributed over an area of 0.30 m x 0.30 m in round or square section, is applied at right angles to the wall at any point on either face they shall resist without:

1. permanent deformation greater than 1 mm

2. elastic deformation greater than 15mm."

GPA, Statement no. 07

The Gypsum Product Association (GPA) offers guidance on selecting appropriate drywall systems for which lightweight metal stud drywall constructions are predominantly known as ‘Shaftwall’, drylining systems that can be constructed entirely from one side where access is restricted to the opposite face.

The GPA are recommending that the testing methodology as set out in BS5234: Part 2 Specification for performance requirements for strength and robustness as a potential suitable method of appraisal. The GPA suggest for a dry-lining system which satisfies the Severe Duty stiffness criteria to Annex A this would be an appropriate test standard to be adopted. Severe duty [SD] grade to the Annex A test methodology limits deflection to 10mm and residual deflection to 1mm.

When tested to BS 5234-2 Siniat Shaftwall systems achieve Severe Duty to Annex A thereby satisfying the guidance by the GPA and can be considered satisfactory to BS EN 81-20:2020.

Standard installation guidance for Siniat Partition systems including Shaftwalls can be found in the Siniat Drywall Manual.