Building Measurement Notes All weeks PDF

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Building Measurement 200486.3 Lecture notes for all weeks...

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Building Measurement Notes (Week 1: Quantity Surveying) The Quantity Surveyor Is: - A qualified professional who specialises in building measurement and estimating the value of construction costs - Also known as a Construction Economist or Cost Manager - They are not to be confused with ‘land surveyors’ or ‘building surveyors’ Quantity Surveyors get their name from the Bill of Quantities: - This is a document which itemises the quantities of materials, labour and services trade-wise in a construction project Skills of Quantity Surveyors: - Traits: o Enjoys the building process o Competent and reliable o Systematic and orderly - Skills: o Good communicator o Able to concentrate for long period o Good at mathematics Role of Quantity Surveyors - At Feasibility Stage: o Consultant QS use their knowledge of construction methods and costs to advise the owner on the most economical way of achieving client requirements - During Design: o Consultant QS ensures that the design remains on budget through Cost Management o On completion of design and drawings, the Consultant QS may prepare Bill of Quantities, which is issued with other tender documents, for use by contractors in submitting tenders o The contractors QS/estimators generally prepare tenders based on this - During Construction: o Consultant QS are called on to fairly value progress payments that would be prepared by the contractors QS/contract administrator Traditional Role: - Measurement and quantification - Document preparation, especially bills of quantities - Cost control during construction Evolved Role: - Investment appraisals - Whole life costing - Value management

Week 2: Bill of Quantities General format of the BQ - Item no - Each item in the bill is indexed by letters and/or numbers - Description - Description should confirm to the requirements of ASMM and - should give necessary details for pricing - Unit - There relevant units in ASMM should be used - Quantity – When transferring quantities to the bill from the measurement sheets (take-off sheets), it should be rounded up to the next whole unit (expect for tonne (t) where it is billed to 2 decimal places) - Rate and Amount - The rate is the price per unit (unit rate) and when this rate is multiplied by the quantity, you get the total amount of that item

Functions of BQ - BQ is part of the tender documents (legal document) o Assist with construction planning and monitoring o Ordering of material and subcontract quotations - Provide a uniform basis for cost management Why not without BQ Tenders based on drawings and specifications without BQ will: - Lose a chance for QS to spot out errors or discrepancies in drawings and specifications - Require the tenderers to take off their own quantities, also time consuming and costly When to Use BQ The recommendation of the Australian Institute of Quantity Surveyors is that BQs be provided for projects: - Where the anticipated reduction in the tender price is calculated to be greater than the fee for producing the BQ - For even less complex projects with an estimated construction cost greater than $2 M Components of Bill of Quantities - Preliminaries – The “preliminaries bill”, usually the first section in the BQ, describes the nature and extent of the work that affects the physical execution of the works. The preliminaries section comprises all general costs not specifically related to any one trade - Preambles – Defined as general descriptions of workmanship and materials relating to the work sections, which may affect price but are probably better excluded from the item descriptions - Measured Quantities – This is the main component of the BQ. For each item in the sections, the quantity is given and is priced by the contractors during the tendering process - Provisional Sum – Cannot be entirely foreseen, defined or detailed, at the time the tendering documents are issued, it shall be stated as a provisional sum - Prime Cost Sum – A sum provided for works or services to be executed by a nominated subcontractor, or for materials or goods to be obtained from a nominated supplier

Week 3: Building Measurement What is Measurement? - A process of translation of the information stipulated in drawings or other relevant documents into descriptions and quantities Why measurement in construction works? - Establishing a budget price, giving tender estimate, providing contract tender sum, evaluating the amount to be paid to a contractor Need for a standard of measurement - Brick wall in area (m2) - Excavations in volume (m3) - Doors and windows in numbers (no) Standards and other practices - Australian Standard 1181-1982 Method of Measurement of Civil Engineering Works and Associated Building Works (Civil method) Tools for Manual Measurement - Scale Rule, Calculator, Pens and Ruler, Colour Pencils Computerised Measurement - There are advanced software that help with taking-off (measurement), BoQ preparations and many other QS functions (CostX, Buildsoft) Three Stages of Bill Preparation - Stage 1: Taking-off (Measure) o Dimensions are read and measured from drawings and entered in a recognized form or special ruled paper (like measurement paper or schedule) - Stage 2: Working Up (Extend) o This stage involves ‘squaring the dimensions’. That means calculating the final quantities (lengths, areas and volumes) for that item - Stage 3: Editing (Bill) o All the descriptions and quantities are then put in a logical order (called abstracting) and a draft bill is written. Final checking of typos and errors is carried out at this stage

Week 4: Groundwork Groundworks - Ground works involves substructure work including construction of foundations, usually concrete slabs that provides the foundation for the building eg. Strip foundation, pad foundation and waffle pod Ground Work

Reading the Tables - Horizontal lines divide classification table and supplementary rules into zones, to which different rules apply - The supplementary rules above the heading ‘Classification table’ are common for all measurement items in that section Foundation Types - Strip Foundation: The most common in simple building and housing constructions - Pad Foundation: Used to support an individual point load and are usually shallow - Raft Foundations: A slab of concrete containing a steel reinforcement that is combined with the ground floor slab - Pile Foundation: Thin columns of reinforced concrete that transmits the load deeper into the subsoil - Waffle Pod Systems: Waffle slabs are a reinforced concrete footing and slab system constructed on ground. They consist of a perimeter footing (edge beam) and a series of narrow internal beams (strip footings)

Week 5: Bill Preparation BQ Descriptions should be given in the following order: - NAME → SIZE → DESCRIBE → FIX QS Terminology - Bill, measure and extend: The total quantity surveying process of writing a description, measuring the quantity from the drawings, carrying out all necessary calculations and, finally, billing the answer - Item: A description involving a cost to the builder but where no quantity is required to be given - Note: A description involving no direct cost to the builder but which will influence the pricing of subsequent descriptions Format of Bill of Quantities - Order of items in the bill, Use of headings, Referencing items, Totalling pages, Collection pages, Summary, Cover Methodology of BOQ Preparation - Determine appropriate service and fee o Submit fee proposal defining scope of service and obtain client agreement o What method of measurement to be used, extent of works to be measured - Planning Stage o Review programme for works and check availability of resources o Brief team leader with direct responsibility for control of measurement team and completion to programme - BOW Setting Up o Set up computer systems, agree trades structure for BOQ - Measuring (take-off) stage o Start measurement of works by team members o Report any deficiencies in documentation to other consultants in writing using Query Sheets and obtain clarification - Checking Stage 1. Correctness of figures, correctness of units of measurement 2. Sections and subsections of the bill are headed properly 3. Main quantities in the bill make approximate calculations - Final Checking o Edit completed trades sections by team leader o Assemble master set of all drawings and specifications used, check and tick off and confirm that all work has been measured - Final Bill Preparation o Print and issue BOQ o Prepare and issue addenda to BOQ covering any discrepancies identified during checking and any changes covered by addenda to drawings

Week 6: Concrete and Formwork Concrete Work Measurement - Formwork and reinforcement for slabs, walls, columns, beams and stairs are measured separately In-situ Concrete - Material: Mixture of cement, coarse aggregate, sand and water - Labour and Plant: Stages of production – mixing, placing, vibrating and curing - Footings: Bases, pile caps, pad footings, strip footing, ground beams Substructure Concrete Elements - Strip footing, concrete footings, Isolated footing beam, Attached footing beam, Rat baffle wall - The length for beams is taken between columns Formwork - Timber or steel frame temporarily constructed to pour concrete General Rules - Measurement and prices shall be deemed to include for placing in position, making good after removal of formwork and carting in all required items, additional concrete required to conform to structural and excavated tolerances

Week 7: Reinforcement Splices and Laps - Reinforcement bars (rebars) are available in certain lengths - Therefore, need to splice them together for longer runs - A common way to splice bars is lap them Hook / Cog Ends - Ends are hooked or cogged / bent to provide grip Shape Code - Similar to hook or cog ends, allowances should be added for other bends based on the shape code Shapers / Chairs - Spacers or chairs are placed underneath or between bars to ensure cover of concrete (may be small precast concrete blocks, concrete rings or plastic fittings Concrete Cover - Concrete cover is maintained to prevent rusting of the bars - The cover to the reinforcement is: the thickness of concrete between the reinforcement and the edge of the concrete section High Yield vs. Mild Steel - Quality of steel slated - Plain round bars (smooth) - Deformed (ribbed or twisted for superior bonding qualities) Bar Notation - Sequence of description of identification marks on drawings for steel reinforcement bars is as follows: Number_Size_Mark_Centres_Location Reinforcement - Footings, Slabs, Walls, Columns, Beams, Casing to Steelwork, Stairs and Landings - Ties are such as links, spacers, stirrups, bindings and similar items Rolling Margin - Difference between the theoretical and actual weight of the steel

Week 8: Finishes General Measurement Rules - Measure the area to be covered (the area before finishing) Work to surfaces...