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- 1. CE 145 - QUANTITY SURVEYING ENGR. MANUEL A. RANGEL JR.
- 2. INTRODUCTION QUANTITY SURVEYING is an assessment of the cost based on certain rates of materials and labour. - the quantification/estimation of works for a construction project and costing them QUANTITY SURVEYOR - is a trained person in construction works’ quantification and costing and contract procedures.
- 3. INTRODUCTION 1. Roles of a Quantity Surveyor a. Prepares the bills of quantities b. Approximates the estimate of costing in every stages of the formation of the building project. c. He plans for the client so that he gets the best value of his/her money for any construction projects to be carried out ( cost planning) d. Examines, the tenders and prices of the BOQ and reports his findings to the architect e. Negotiates with the contractor the desired amount to pay to him for the contract f. Advices the client on the selection of the contracton g. Values work in progress and recommends payment to be made to the contractor.( valuation) h. Advices on financial aspects of the contract valuation( Cost advise) i. Prepares the final account when the contractor finishes the work j. He prepares the tender documents k. Advises on the form of contract
- 4. INTRODUCTION 2. Essentials of a Good Quantity Surveyor a. He must be able to describe clearly, fully and precisely the requirement of the architect and arrange the BOQ in such a way that the works can be quickly and accurately cost. b. Must be able to write in clear technical language that will not be miss-understood c. Must have sound knowledge of the building materials, construction techniques and of customs prevailing in the industry d. Must be able to accurately interpret construction drawings e. Must be careful and accurate in making calculations f. Must have a systematic and orderly mind to be able to visualize the drawings and details g. Must have good knowledge of the construction prices ( to be able to offer cost advise) h. Must have ample knowledge of the law of contract i. Must be competent to conveyor to the person who is to price the BOQ, the quantity and quality of the materials required and the nature of labour to be applied during the construction of the structure.
- 5. INTRODUCTION 1. Drawings (Plans) – the basis for quantity take-off Steps to avoid errors in estimating a. Look over the drawings and attempt to visualize the work entitled b. Study the plans If they are in agreement with one another c. Check drawings’ dimensions carefully to see that each overall dimension agrees with the total room dimensions. d. If the dimensions do not exist in some places, then it is always better to write them in.
- 6. INTRODUCTION 2. Bill of Materials (BOM) – is a document that outlines all the raw materials and labor required to build a project or structure, meticulously detailed in terms of quantities.
- 7. INTRODUCTION 3. Bill of Quantities (BOQ) – a document that lists the total materials required to complete a construction project. The list includes materials, labors and equipment. BOQ allow for quick and easy comparison of contractor proposals. Advantages: a. It forms a common basis for competitive tendering which is necessary to obtain a reasonable value for consideration b. It forms in itself a basis of rates for measured work which can be used in the contract for valuation of variations and final account. c. It is used in building operations for the completion of interim payments.
- 8. INTRODUCTION 4. Specification – special description or a particular subject. It contains detailed description or all workmanship and materials which are required to complete an engineering project in accordance with its drawings and details. Importance of specifications: a. The cost of the unit quantity of work is governed by its specification. b. Specifications of work are required to describe the quality and quantity of different materials required for construction work and are one of the essential contract documents. c. It also specifies the workmanship and the method of doing the work. It serves as a guide to the supervising staff of the contractor as well as to the owner to execute the work to their satisfaction. d. Work is carried out according to its specification and the contractor is paid for the same. Any changes in specification change the tendered rate.
- 9. INTRODUCTION e. As the rate or work is based on specification, a contractor can calculate the rates of various items of works in a tender with his procurement rates of materials and labor. f. Specification is necessary to specify equipment, tools and plants to be engaged for a work and thus enables to procure them beforehand. g. To verify and check the strength of materials for a work involved in a project. h. Specification is an essential contract document and required for arbitration of court cases.
- 10. INTRODUCTION 5. ITEMS OF WORKS IN BUILDING CONSTRUCTION 1. Earthworks a. Excavation b. Backfilling and compaction c. Grading and compaction d. Gravel bedding e. Soil poisoning 2. Structural Works a. Concreting b. Rebar c. Formworks d. Steel and metal works 3. Architectural Works a. Masonry – chb laying, plastering b. Finishes – painting, tiles c. Door and window d. Roofing 4. Plumbing Works a. Storm drainage b. Sanitary and sewer line c. Water distribution line d. Plumbing fixtures, ST 5. Electrical Works
- 11. INTRODUCTION 6. UNIT OF MEASURES - mainly categorized for their nature, shape and size and for making payments to the contractor and also. The principle of units of measurements normally consists the following: a) Single units work like doors, windows, trusses etc., is expressed in numbers. b) Works consists linear measurements involve length like cornice, fencing, hand rail, bands of specified width etc., are expressed in lineal meters (lm) c) Works consists areal surface measurements involve area like plastering, white washing, partitions of specified thickness etc., and are expressed in square meters (m2) d) Works consists cubical contents which involve volume like earth work, cement concrete, Masonry etc are expressed in Cubic metres.
- 12. INTRODUCTION 7. RATE ANALYSIS - is the basis for arriving at a correct and reasonable rate per unit work or supply for a specific item based on its specification and a detailed survey of materials, labor, equipment, and so on as required for the unit work and their prevailing rates. Purpose of Rate Analysis a. To determine the current rate per unit of an item at the locality b. To examine the viability of rates offered by contractors c. To calculate the quantity of materials and labour strength required for the project planning d. To fix up labour contract rates
- 13. INTRODUCTION 7. RATE ANALYSIS The price of a work item is composed of the following components, and the sum of these is the rate per unit of an item. (a) Material Cost (b) Labor Costs (c) The cost of equipment, tools, and plants (d) Overhead expenses or establishment charges (including incidental) (e) Profit
- 14. INTRODUCTION Factors affecting the Rate Analysis: The cost of a piece of work is primarily determined by the following factors: (1) Item specification indicating the quality and proportion of materials, method of construction, and work protection. (2) The current material rate for the item of work up to the worksite. (3) Daily wages of various categories of laborers in the area, along with their respective outputs. ; (4) The range of lead and lift required for material deposition to complete the item or work. (5) Overhead charge as a percentage, which includes insurance and the possibility of theft or loss, among other things. (6) The profit range and water availability in connection with the construction work.
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