Interim certificate

Monthly valuations of work-in-progress are carried out in order to make stage payments to the contractor .
This includes the physical meaasurement of the work on the site and materials delivered.
The valuation for interim certificates should be made as accurately as is reasonalby possible , and the contrctor is entitled under the terms of the contract to the full value of work executed on site , less a specified retention sum .

One of the main functions of the contractor's quantity surveyor is to ensure timely and full payment for work carried out on site .
For most contractors interim valuations and certificates form their only source of income , from which they fund the whole of their building operation .
In general , building contracts provide within their conditions regular and timely payments to the contractor .
Interim valuations are prepared by the Quantity Surveyor whenever the architect considers them to be necessary for the purpose of ascertaining the amount to be stated as due in an interim certificate .
The architect is contractually bound to issue interim certificates at the period stated within the conditions of contract.

Qs will assess the value of any variations and extras and these costs will be included in interim valuations

Good practice of Architect - keep QS informed-any defective or improperly executed work .

The certificate - is not a conclusive evidence that that any works , materials or goods included are in accordance with the contract . The elemtns to be included within an interim certificate can therefore be summarized as

- Preliminaries
-measured work
-valuation of architect instruction or variotion
-Re-measurement of provisional irtems , prime cost (PC) sums and provisional quantities .
-valuation of nominated subcontrators and supploiers materials off-site
- Fluctuations , where they are allowed within the contract provision .