Design Considerations for Modular Open Building Systems

Modular construction is widely used for residential buildings of 4 to 8 storeys. In the context of open building systems, modular construction provides a systemised approach to design in which the benefits of prefabrication are maximised. There is demand to extend this form of construction to more than 12 storeys for residential buildings. This paper presents a review of modular technologies, and describes load tests and analysis on light steel modular walls that are used to justify the use of light steel technology to support higher loads. For taller modular buildings, the effect of installation and geometric inaccuracies must be taken into account and it is proposed that maximum out of verticality of a vertical group of modules is 50mm relative to ground datum. Using these geometric tolerances, the notional horizontal force used to evaluate stability of a group of modules should be taken as a minimum of 1% of the applied vertical load on the modules. Robustness to accidental load effects is important in all high-rise buildings and it is proposed that the tie force in the connections between modules should be taken as not less than 30% of the total vertical load applied to the module in both horizontal directions.