5 of 9 Construction of Giresun Wastewater Treatment Plant VOLUME 4 – Schedules of Payments  Twenty five percent (25%) of the price stated in the corresponding Schedule item, upon issuing of  the Taking Over Certificate.  4.1.4 Payments  The Contingency Sum in the Grand Summary shall be used at the discretion of the Engineer to meet  additional eligible costs under the contract. It is a reserved budget and entered in the Schedules to cover  any additional work or supplies where the extent is not known at the time of tendering and shall as such  only be executed on the written instruction from the Engineer. It shall be used in the same way as  provisional sums as set down in minor modifications to sub-clause 13.5 of the Conditions of Contract. The Total Tender Price shall, after revision to incorporate any modifications agreed during contract  negotiations, become the Contract Price on signing of the Contract Agreement.  In the case where the descriptions of the individual items do not fully cover the required works or the  Tenderer wants to add installations, the Tenderer shall fill in the blank cells under Any Other Items in the  Schedules of Payments.  The prices entered in the Schedules of Payments shall be used for calculating payments and interim  payments and for valuing variations.  For the measurement of the works, the percentages of the executed work will be calculated according to the  breakdown of the quantities under each lump sum price. The detailed quantities shall be prepared by the  Contractor during the design phase and shall be submitted to the Engineer with the designs for approval.  The following principles shall apply to the measurement of the works for lump sum items:  - the amount due shall be determined on the basis of the breakdown of each of the lump sum prices and a  percentage of that price corresponding to completed stages of the work.  Interim Payment Certificate for Advance Payment shall include scanned documents of the Contract in  CD/DVDs numbered as per the precedence order in Contract Form.  The Contractor’s Application for Interim Payment Certificates Statement shall include the annexes  requested by Employer or Engineer electronically in CD/DVDs as per the following order in separate  folders:   Calculation Sheets   Monthly Progress Reports as per Volume 2 Particular Conditions Sub-Clause 4.21   Site Check Forms   Test Reports   Non Conformance Reports   Announcement for Workers  Social Security Documents (including self-declarations of workers)   Copy of Insurances   Copy of Certificate of Origins (if applicable)   Register of Variation Orders and copies of variation orders   Payment Forecast for the following 3 months for all items in the schedules that is also shown on a  Gantt chart.  Page 5 of 9  August 2020 d4w_finoffer_4.2_en.doc