Technical Booklet D Structure·Page 19·3.4
Class 1 buildings – robustness measures
Class 1 buildings require no additional robustness measures if designed and constructed to the publications in Section 2 or (for single-family houses of 3 storeys or fewer) Section 4 guidance.
For a Class 1 building, provided the building has been designed and constructed in accordance with the publications specified in Section 2 or, in the case of a single family house of not more than 3 storeys, the guidance given in Section 4, to satisfy the requirements of regulation 30 in Part D, no additional measures are necessary.
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