Any compensation event quotation should include risk allowances for cost and time that have a significant chance of occuring and are at the Contractor's risk. This would include weather that is below the threshold of assessment under clause 60.1 (13).
If the Subcontractor has not included this risk, then there would be no reason why the Contractor could not make a reasonable assessment, although based on the effect on their works. For example, the Subcontractor may have priced for 10 days work which could equate to 12 days with a reasonable assessment of weather risk. The Contractor could, therefore, include 2 days of associated attendant resources, although the assessment of Defined Cost for the Subcontractor would remain as 10 days, unless the weather conditions become a further compensation event.
A general percentage addition, to my mind, is not an adequate assessment of Defined Cost as it is not based on the principles of the Shorter Schedule of Cost Components, where the only 'allowable' percentage additions are people overheads and design overheads. Every other cost component is calculated by an assessment according to what is stated. I see no reason why risk allowances should not be calculated in this way, unless you agree otherwise.
An assessment of weather should be a logical calculation based on a comparison of when work was planned to be undertaken with the revised planned times. The 'difference' in weather conditions would be the subject of the quotation assessment. For instance by comparing the number of days of rain, frost, snow etc and pricing the measures required to account for these, such as protection, water pumping, road mats etc. The percentage may also be a 'catch all' and include a shortened working day (summer to winter). The best way to assess this would be to start with a detailed programme which you can agree to and then calculate the activity differences using the applicable Accepted Programme.
It is possible that a percentage addition is easier for the Contractor, especially as the cost of preparing quotations is not a Defined Cost under NEC3 Option A, although it is a 'crude' way of assessment.
If the Subcontractor has not included this risk, then there would be no reason why the Contractor could not make a reasonable assessment, although based on the effect on their works. For example, the Subcontractor may have priced for 10 days work which could equate to 12 days with a reasonable assessment of weather risk. The Contractor could, therefore, include 2 days of associated attendant resources, although the assessment of Defined Cost for the Subcontractor would remain as 10 days, unless the weather conditions become a further compensation event.
A general percentage addition, to my mind, is not an adequate assessment of Defined Cost as it is not based on the principles of the Shorter Schedule of Cost Components, where the only 'allowable' percentage additions are people overheads and design overheads. Every other cost component is calculated by an assessment according to what is stated. I see no reason why risk allowances should not be calculated in this way, unless you agree otherwise.
An assessment of weather should be a logical calculation based on a comparison of when work was planned to be undertaken with the revised planned times. The 'difference' in weather conditions would be the subject of the quotation assessment. For instance by comparing the number of days of rain, frost, snow etc and pricing the measures required to account for these, such as protection, water pumping, road mats etc. The percentage may also be a 'catch all' and include a shortened working day (summer to winter). The best way to assess this would be to start with a detailed programme which you can agree to and then calculate the activity differences using the applicable Accepted Programme.
It is possible that a percentage addition is easier for the Contractor, especially as the cost of preparing quotations is not a Defined Cost under NEC3 Option A, although it is a 'crude' way of assessment.