|INTRODUCTION TO CIVIL ENGINEERING QUANTITIES |
In the 17th century, architects were responsible for the design and erection of buildings and the “measuring & estimating” were done by the craftmen and each craftmen will employ his own method of measurement. These practices were found to be very unsatisfactory due to the difficulty in reconciling the actual material used and the measured works carried out. In later years, it was thought a uniform systematic of measurement and presentation is necessary. The various professional known as the Standard Methods of Measurement.
|1.1 PURPOSE OF BILL OF QUANTITIES |
The outlines of certain conventions and define terms, which apply to bill preparation and measurement processes generally:-
"QUANTITIES" - Estimated amount of labour and the materials required to carry out the project under the various items of work.
"BILL OF QUANTITIES" - List of items giving the quantities and brief descriptions of work to be carries out with its respective quantities and unit cost rate for carrying out each trade.In conjunction with the other Contract Documents, it forms the basis on which tenders are obtained.
When priced, it affords a means of comparing tenders.
When the contract has been entered into, the rates in the prices Bill of Quantities are applied to assess the value of the actual quantities of work carried out.
The Bill of Quantities should be prepared and measurements made in according with the procedure set out in the CESMM, unless other methods of measurement are preferred by the Promoter (Employer/Purchaser).
|1.2 STANDARD METHOD OF MEASUREMENT |
"STANDARD METHOD OF MEASUREMENT" - SMM is a document stipulating guidelines on the method of measurement of any particular trade. These guidelines give the different components of an item to be measured (taking-off) and describe in a manner which is easily understood so that all tenderers can price them on the same basis.
"TRADE" - The works or practice of certain craft for example bricklayer, plumber etc. Civil Engineering Works (CEW) are classified under different trades and this will help the civil engineer in pricing the different categories of works.
"TAKING OFF" - The process of measuring from drawings and recording all dimensions in recognized form on a special ruled paper called “Dimension Paper”.
"SQUARING DIMENSIONS" - The process of multiplication and / or addition / subtraction of recorded dimension for the purpose of obtaining the linear, square or cubic measurements.
"ABSTRACTING or WORKING-UP" - The process of collecting of measurements of identical character and description, under different tracks and reducing them to units as required by CESMM"BILLING" - Writing the draft bill for the Abstract.
"CESMM" - The rules and provision of the Civil Engineering Standard Method of Measurement are applicable to the preparation of Bill of Quantities for and the measurement of CEW such as earthworks, roads, bridges, structures, culverts, sewage, etc and quantities are usually prepared by the civil engineers. They are not intended to apply to the preparation of bills of quantities for @ the measurement of mechanical eng., electrical eng. or building work. CESMM document contains 8 numbered sections. The first 7 sections are each divided into Paragraph. Section 8 is divided into 24 main classifications.
"CONDITIONS OF CONTRACT" - Defines the terms under which the work is to be carried out, the relationship between the Promoter and the Contractor, the powers of the Engineer and the terms of payment.
"SPECIFICATION" - Describes in detail the work to be executed, the character and quality of the materials and workmanship, any special responsibilities of the Contractor that are not cover by the Conditions of Contract. It may also lay down the order in which various portions of the work are to be executed, the methods to be adopted and particular of any facilities to be afforded to other contractors. Care should be exercised when drafting the specification to avoid conflict with any of the provisions of the conditions of contracts.
"ESTIMATING" - The process of costing the project of each item or trade after the quantities has been measured and summing up the items to arrive at a total estimated cost for the whole project.
|1.3 STANDARD USED IN MALAYSIA |
i) CESMM - Civil Engineering Standard Method of Measurement is used in conjunction with CEW and quantities is prepared by the civil engineers.
ii) SMMM - Standard Method of Measurement of Malaysia is used in conjunction with building works and the quantities is prepared by the Quantity Surveyors (QS).
1.3.1 COMPARISON OF METHOD OF MEASUREMENT OF CESMM AND SMMM
|Table 1.1: Comparison of Method|
|No.||METHOD OF MEASUREMENT|
|1||B.Q. and specification form part of contract. Contractions must always refer to specification for further clarification.||B.Q. contracts|
|2||When tendering contracts must always make provision for any temporary or diversion works etc. which are normally mentioned in the B.Q.||Temporary and diversion works are classified as separate action items of works.|
|3||Use m3 as unit of measurement for concrete slab to allow for flexibility in case alteration is required in the structural design, etc.|
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