1.1 In the Secretary of State’s view the requirements of A1 and A2 will be met by following the recommendations given in the documents listed in Section 1 or by adopting the guidance in Sections 2-4:
- a. Section 1 is relevant to all building types and lists Codes, Standards and other references for structural design and construction but, where they do not give precise guidance, consideration should be given to paragraph 0.2.
- b. Section 2 give sizes of structural elements for certain residential buildings and other small buildings of traditional construction.
- c. Section 3 gives guidance on the support and fixing of wall cladding.
- d. Section 4 gives guidance where roofs are to be re-covered as a material alteration as defined in the Regulations.
1.2 The safety of a structure depends on the successful combination of design and completed construction, particularly:
- a. The design should be based on identification of the hazards to which the structure is likely to be subjected and assessment of the risks. The selection of relevant critical situations for design should be made reflecting the conditions that can reasonably be foreseen during future use.
- b. Loading. Dead load, imposed load and wind load should be in accordance with the current Codes of Practice referred to in section 1 of this document.
- c. Properties of materials.
- d. Detailed design and assembly of the structure.
- e. Safety factors.
- f. Workmanship.
The numeric values of safety factors, whether expressed explicitly or implicitly in design equations, or design values, should be derived from considerations of the above aspects of design and construction as a whole. A change in any one of these aspects may disturb the safety of the structure.
Loads used in calculations should allow for possible dynamic, concentrated and peak load effects that may occur.
1.3 Grandstands and structures erected in places of public assembly may need to sustain the synchronous or rhythmic movement of numbers of people. It is important to ensure that the design of the structure takes these factors into account so as to avoid the structure being impaired or causing alarm to people using the structure.
Guidance on the design and testing of grandstands may be found in ‘Dynamic performance requirements for permanent grandstands subject to crowd action – Recommendations for management, design and assessment’ published by The Institution of Structural Engineers, December 2008.