NEC ECS: Completion Date for a Subcontract which includes Maintenance

We as the Contractor have a contract completion date in July 2020.

Within the Works Information we are required to provide 12 months of maintenance to the landscaped areas on site, we have included this requirement within our landscaping subcontract, as a lump sum item within the subcontract BOQ (the landscaping subcontract is yet to be executed).

The subcontract completion date was drafted as July 2021 to account for the 12 months maintenance period required, following completion of the main works.
This has however been flagged by others as incorrect, on the basis that subcontract completion cannot occur after main contract completion, not to mention that the Subcontractors retention would not be released until a further 12 months after main contract completion, with the Subcontractors defects period starting 12 months after the Contractors also.

The premise of a July 2021 subcontract completion date was to allow for all works in the BOQ to be undertaken prior to subcontract completion, thus avoiding a situation whereby completion is certified and retention is released prior to all works being completed.

Can anyone advise the correct approach in this situtation?

I would check on the thought that "subcontract completion cannot occur after main contract completion’. I don’t think the standard form of the ECS contains this provision. The standard contract data does not require this to be stated, nor is there an optional statement for it, so it wouldn’t ordinarily be a binding part of the subcontract agreement.

The standard retention clause could be amended by agreement and the Completion date left the same to allow retention release immediately on Completion of the maintenance works. If done correctly, this could preserve the Contractor’s entitlement to hold retention until all works are completed and prevent early trigger of the defects date etc., while ensuring a fair release timescale.

The subcontract is administered independently from the main contract and stands alone from it, in fact there are few references in the subcontract to the main contract. It is therefore possible to have the subcontract completion date after the main contract completion date.

References in the ECS to the terms Completion and Defects Certificate are in relation to the subcontract and not the main contract and the defect date is defined as x weeks after Completion of the whole of the subcontract works. So under Option X16: Retention the first half is retained until the earlier of Completion of the whole of the “subcontract works” or when the Contractor takes over the whole of the “subcontract works” with the second half released when the Defects Certificate is issued (note the term Defect also refers to “subcontract works” so it means a certificate under the subcontract and not one under the main contract.

In your scenario this means the first half of retention will be released in July 2021 and the second half in July 2022 (assuming no early or late finish).