Gruner is a long-established Swiss multidisciplinary engineering group whose fire-safety unit delivers interdisciplinary fire protection across all SIA project phases — fire strategies, engineering-method verification, evacuation and smoke-gas (CFD) simulation, structural fire design and technical fire protection (sprinklers, smoke control, fire-control systems). It is one of Switzerland’s longer-established fire-engineering teams. Its fire-engineering outputs support, and do not replace, the professional judgement of the responsible engineer.