1.2.12  Structure

The structural frame shall be designed in accordance with the recommendations made within the relevant British Standard or Code of Practice to support the following dead and imposed loading.

Dead Loads shall be calculated in accordance with BS 648
Imposed Floor Loads shall be calculated in accordance with BS 6399: Part 1.
Minimum loading throughout to be 4kN/m2 + 1kN/m2 (Partitions).
Plant room loading to be 4kN/m²
Imposed Roof Loads shall be calculated in accordance with BS 6399: Part 3.
Imposed Wind Loads shall be calculated in accordance with BS 6399: Part 2.

Construction of the floors shall be in-situ concrete, precast concrete or composite decking, or a combination of the 3, designed in accordance with the recommendations of BS 8110 - 1:1997 or BS 5950: Part 4 for the loadings given above.

Any structural steelwork used in the construction shall be adequately protected against corrosion to suit the environment in which it is located. A life to first maintenance in excess of 25 years to BS 5493 is required.

The overall stability of the structure shall be provided by either shear walls, located to suit the architectural detailing and to avoid all other door and window openings by diagonal bracing, or by rigid frame action, or a combination of the above. Front walls to lift shafts must be in block work. Such provision shall not limit flexibility of use.

The floor to ceiling height will be set at 2.8m as a minimum14.

Wind bracing is to be hidden within the depth of external walling.

Where concrete work will be exposed in the finished works, eg. plant rooms, ducts, etc., it shall be constructed and finished to a plain smooth finish standard as a minimum.

Exposed steelwork shall be primed to provide a life to first maintenance of 25 years. It shall be finished with an appropriate decorative product. Concealed steelwork should have a minimum design life of 60 years

All necessary expansion jointing within the structure shall be carefully co-ordinated with the aesthetic requirements of the external cladding. Coating materials are to provide a life to first maintenance in excess of 25 years.

Any metal roof and cladding panels shall be supported by metal purlins and cladding rails fixed to the structure. The cladding and supporting purlins and rails shall be designed to resist the imposed roof and wind loads stated above. The fixing of cladding to the supporting rails shall also be designed to withstand the worst combination of wind and imposed loads. Fixings themselves shall be designed such that they are corrosion resistant for a period of at least 60 years.

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14  Where the facilities include a Custody Suite this shall be increased to 3.0m within the Custody Suite.