11.1.6 Structural design
MMC systems shall be designed to support and transfer loads to foundations safely and without undue movement and shall have adequate resistance to all imposed loads. Issues to be taken into account include:
- compliance with relevant standards
- stability or resistance to lateral load
- structural robustness.
11.1.6.1 Compliance with relevant standards
All load bearing elements should be designed to comply with relevant standards:
| Basis of structural and geotechnical design | BS EN 1990 and relevant NA |
| Actions on structures | BS EN 1991, all parts and relevant NAs to these parts |
| Material codes | BS EN 1992 — EN 1999. Eurocodes for all materials and their relevant NAs |
| Low-rise building structures | BS 8103 (all parts) |
| Medium rise building structures of over three storeys high | Designed by an engineer in accordance with Technical Requirement R5 |
| Structural robustness and mitigation of disproportionate collapse in buildings | BS EN 1991, all parts and relevant NAs to these parts Building Regulations — eg AD A in England & Wales IStructE’s publication of Practical guide to structural robustness |
11.1.6.2 Stability/resistance to lateral load
MMC systems forming homes or buildings containing homes shall be adequately designed to ensure that all loads are safely transferred to the foundations, without undue movement/distortion or impairing the health and safety of the building occupiers.
Whatever the system of resistance to lateral loads (ie, single material or hybrid system) that is being deployed for stability purposes, they should be demonstrated as being fit for purpose and within acceptable deflection limits for the type of structure and cladding used.
Effective connections of MMC modules or panels to any structural framing or strong point(s) used should be adequately provided and should be visible or inspectable. Where such connections are to be covered up in their final state, the installation is to be inspected and verified in accordance with the system verification plan (see Clause 11.1.10).
Manufacturing and erection tolerances should be clearly stated and allowed for in the design.
11.1.6.3 Structural robustness
MMC systems forming homes or buildings containing homes shall be adequately designed to ensure that the building is sufficiently robust to reduce the sensitivity of the building to disproportionate collapse in the event of an accident. This requirement will be considered met when the building is sufficiently robust to sustain a limited extent of damage or failure, depending on the consequence class of the building, without collapse. Further guidance can be found in The Institution of Structural Engineers publication ‘Structural robustness and disproportionate collapse in buildings’.
Last updated: 2nd January 2025