When do I adopt it?

The updated MCHW will start to be implemented in contracts let after the MCHW publication date. For details relating to the implementation of the MCHW, refer to GP 110 requirements.

But what if…

  • I have an existing construction contract let before the MCHW publication date and I wonder whether I have to redraft my contract-specific specification to align with the updated MCHW. It is not envisioned that the updated MCHW would be used.
  • I have an existing construction contract let before the MCHW publication date and I now need to update the contract-specific specification. Should I use the updated DMRB and MCHW documents? In this case, there is a contract change, hence the project team would need to decide how they wish to implement the design changes, including an option for them to use the updated DMRB. It is not envisioned that the updated MCHW would be used to draft the updated contract-specific specification. This would need to be confirmed and recorded by the project team.
  • I have an existing design contract (i.e. design to the old DMRB) which was let before the MCHW and associated DMRB consequential amendments’ publication date, and I need to start drafting the contract-specific specification now. Should I re-design it following the updated DMRB and then use the updated MCHW?
    • It is not envisioned that a re-design would be needed. This would need to be confirmed and recorded by the project team.
    • In terms of drafting the contract-specific specification, the implementation requirements stated in GP 110 would need to be complied with. These include the option for Overseeing Organisation not to use the updated MCHW for a project that is advanced in the design stage where that would cause significant additional cost or programme delay. A decision whether to use a new or revised document will depend on the stage of the project and the impact of implementing the new documents. This would need to be confirmed and recorded by the project team. In any case, old and updated MCHW documents cannot be mixed because this would lead to contractual problems.
  • I have a product that has been assessed and/or certified referencing the old MCHW. Can it still be used after the MCHW publication date? Its use depends on the contract under consideration.
    • If the product has to be used under an existing construction contract, then it is not envisioned that the updated MCHW would be used hence it would still be valid.
    • If the product has to be used under a new construction contract, then the updated MCHW requirements will apply.
  • I have a product that has been assessed and/or certified referencing the old MCHW. Should it be re-assessed and certified to be used under the updated MCHW (i.e. for use under a new construction contract)? This depends on the individual product and the adopted reference standard (designated, EADs, non-designated standards) or scheme to certify and/or accept its use (product certification and acceptance schemes). An assessment would need to be made for the individual product to check whether the performance characteristics are still equivalent.
  • Can I adopt technical changes implemented in the updated MCHW and DMRB documents if my project is using the previous version of the MCHW? If the project team wanted to use any of the individual technical changes in the individual MCHW documents then they could use the alterations system for the old MCHW, i.e. by using substitute, additional and/or cancelled clauses as set out in the old Series NG 000. That would need to be assessed for individual technical areas with SR, AR, CR text written in the style of the old MCHW.