NEC ECC: How to deal with the compound problems due to Contractor's Defects?

A Contractor experiences two problems on Site.
A steel staircase has been positioned incorrectly and is misaligned with the first-floor stairwell by 0.5m. This results in expensive remedial work.

To compound problems, the Contractor has tiled walls when the temperature was too low for the grout to set properly and some tiles have cracked and are coming away from the wall. The Scope provided by the Client expressly stated that tiling should not be undertaken unless the temperature exceeded 5 degrees Celsius but the Contractor (to overcome time pressures) ignored this constraint on several cold days.

How are these two issues dealt with in the contract and how will they affect the amount due?

First of all the Supervisor should notify the Contractor, separately, of the 2 Defects because those parts of the works are not in accordance with the Scope (NEC4,) cl 43.2.

The Contractor and Project Manager could consider not having the Defect(s) corrected by changing the Scope, cl 45, however this would seem unlikely and therefore the Contractor is required to correct the Defect(s), cl 44.

The effect on the amount due will depend upon the main Option of the contract and the timing of the work being carried out.

Under Option A or B assuming the notified Defect(s) will delay following work, the work/activity would not be considered as completed and excluded from the Price for Work Done to Date. Under Option C or D in principle the Defined Cost of the work done on the staircase, and the correction costs, would be included in the Price for Work Done ( for the correction costs assuming the Defect is corrected by the Contractor prior to Completion) with the Client and Contractor sharing the additional cost under the share arrangements. You should however check if the cause of the issue fell under Disallowed Cost cl 11.2(26). The correction costs of the tiling would be Disallowed Cost due to the Contractor not having followed a constraint stated in the Scope.