Retainage is the withholding of a portion of the final payment for a defined period to assure a contractor or subcontractor has finished a construction project completely and correctly.
Retainage usually depends on substantial completion Most contracts base the deadline for retainage payments on the date of a project's substantial completion.
A Simple Example of Fixed-rate Retainage To calculate your expected holdback, simply multiply the scheduled payment amount by the retainage rate. In this case, a $30,000 payment x 10% retainage would equal $3,000 in holdback for each payment.
The contingency allowance is the time allocated during planning for unscheduled events. Technical and personal disruptions result in changes in the indirect production costs. The contingency allowance is calculated in special contingency time studies, the results of which yield rates for indirect production costs.
For example, a conceptual estimate may have a contingency of 20% and an allowance of 10%, while a detailed estimate may have a contingency of 5% and an allowance of 2%. However, these percentages are not fixed and may vary depending on the project characteristics and the level of confidence of the estimator.