Business of Interior Design PDF

Business of Interior Design INIFD CORPORATE ACADEMICS SUPPORT  Content  Approximate Method of Costing  Specifications  Taking Out Quantities  Approximate Method of Costing Introduction There are two basic things involved in any construct...

Business of Interior Design INIFD CORPORATE ACADEMICS SUPPORT  Content  Approximate Method of Costing  Specifications  Taking Out Quantities  Approximate Method of Costing Introduction There are two basic things involved in any construction, namely, the quantity aspect and the quality aspect. The study and analyses of drawings which are prepared with respect to the design of the project governs the quantity aspect, and the quality aspect is governed through specifications for materials and workmanship. Thus the quantity aspect decides the quantum of work involved in the construction and it helps in finding out the quantities of various materials required as well as the total labour force necessary for the construction work. These two aspects of construction, namely, the quantity aspect and the quality aspect, lead to form or govern the estimate of the work. Thus estimate is a tool for planning and controlling the construction activity of any project with respect to quality, time and finance. An estimate of a project is, therefore, a forecast of its probable cost. It is usually prepared before the construction is taken up. Before undertaking any work or project it is necessary to know the probable cost which is obtained or derived by estimating. The estimate is prepared by computing or calculating the quantities required and then calculating the cost at suitable rates, to get the expenditure likely to be incurred in the construction of the work or structure. The primary object of an estimate is to enable one to know beforehand the cost of work. The actual cost is known only after the completion of the work from the account of the completed work. If the estimate is prepared carefully and correctly there will not be much difference in between the estimated cost and the actual cost. For accurate estimating the estimator should be experienced and fully acquainted with the methods of construction. The estimate may be prepared approximately as a preliminary estimate by various methods without going into details of the different items of work, to know the approximate cost or the rough cost. Accurate estimate is prepared in detail item wise by detailed estimate. For detailed estimate the work is divided into different items of work, and the quantities under each item are taken out and then an ‘abstract of estimated cost’ is prepared at suitable rates. Provision for contingencies, 3% to 5% of the estimated cost, is made in the estimate to cover the miscellaneous petty expenditures which do not come under any item of work. Provision is also made in the estimate for work charged establishment at 1.55 to 2% of the estimated cost. From the detailed estimate the quantities of various materials and labor required may also be calculated. The estimate also gives an idea of the time required for the completion of the work. The estimate is also required for inviting tenders and to arrange contract and to control the expenditure during the execution. For complete estimate of a project, beside the estimated cost of the different items of the main work, the cost of preliminary works and surveying, cost of land including cost of acquisition, cost of levelling and dressing of ground and the cost of other external services are required to be provided in the estimate. Provision for supervision of departmental charges 5% to 10% of the estimated cost is also made to get the estimated cost of the whole project. The process of preparing an estimate is known as estimating and it includes two items  Taking out quantities; and  Abstracting. Types of estimates: The following are the different types of estimate: -  Preliminary Estimate or Approximate or Abstract Estimate or Rough Cost Estimate.  Plinth Area Estimate  Cube Rate Estimate or Cubical Content Estimate  Approximate Quantity Method Estimate  Detailed Estimate or Item Wise Estimate  Revised Estimate  Supplementary Estimate  Supplementary and Revised Estimate  Annual Repair or Maintenance Estimate (A.R. or A.M. Estimate) Preliminary or Approximate Estimate or Abstract Estimate: Preliminary or Approximate or Abstract estimate is required for preliminary studies of various aspects of a work or project, to decide the financial position and policy for administrative sanction by the competent administrative authority. In case of commercial projects as Irrigation projects, Residential building project and similar projects which earn revenue income, the probable income may be worked out, and from the preliminary estimate the approximate cost may be known and then it may be seen whether the investment, on the project is justified or not. For non- commercial projects or for projects giving no direct returns, their necessity, utility, availability of money etc., may be considered before final decision is taken. The approximate estimate is prepared showing separately the approximate cost of all- important items of work. The estimate is accompanied by a brief report explaining the necessity and utility of the project and showing how the cost of separate items has been arrived at. This is also accompanied with a layout plan. A percentage of about 5% to 10% is added as contingencies. The preliminary estimate may be prepared by various ways for different renovations:  Per unit basis Per student for schools, per classrooms for schools, per bed for hospitals, per seat for cinema and theatre balls, per bay for factories, barracks and dormitories, per tenement for residential building renovations. Approximate cost of a school building for 100 students @ Rs. 5,000/- per student works out as Rs. 5 lakhs. Approximate cost of a 100 bed hospital @ Rs.25, 000/- per bed comes to Rs. 25 lakhs. Approximate cost of a barrack of 10 bays (each bay of 3m and 6m wide) @5,000/- per bay comes to Rs. 50 thousands. Approximate cost of a two-roomed quarter may be Rs. 30,000/- a three-roomed quarter may cost Rs. 1 lakh.   Plinth area estimate for building (P. A. Estimate): This prepared on the basis of plinth area of building, the rate being deduced from the cost of renovation of similar building having similar specification, heights and renovation, in the locality. Plinth area estimate is calculated by finding the plinth area of the building and multiplying by the Plinth Area Rate. The plinth area should be calculated for the covered area by taking external dimensions of the building at the floor level. Courtyard and open spaces should not be included in the plinth area. Plinth area Estimate is only approximate, and is a preliminary estimate, to know the approximate cost beforehand. If the plan of the building renovation is not ready or available, at the beginning just prepare a proposal, floor interior of rooms, etc. may be determined from the requirements and 30 to 40 percent of the total area thus found may be added for walls, circulation and waste to get the approximate total plinth area which multiplied by the plinth area rate gives the approximate cost of the building renovation. The approximate cost of a building renovation having plinth area of 100 sq. m. @ Rs. 900/- per sq. m. works out as Rs. 90,000/- For storeyed building, the Plinth area Estimate is prepared for each storey separately.   Cube Rate Estimate for Building Renovation: Cube rate Estimate is a preliminary estimate or an approximate estimate, and is prepared on the basis of the cubical contents of the building renovation the cube rate being deduced from the renovation cost of the similar building interior having similar specifications and construction, in the locality. This is calculated by finding the cubical contents of the building interior, (length x breadth x height) and multiplied by the cube rate. The length and breadth should be taken as the external dimensions of the buildings at the floor level and the height should be taken from the floor level to top of roof (or half way of the sloped roof). For storied building interior the height should be taken between the floor levels of one storey to top of next – higher floor. Cube rate estimate is most accurate as compared to the Plinth area Estimate as the height of the interior work is also compared. The approximate cost of a building of cubic content (volume) 400 cu. m. @ Rs. 180/- per cu. m. comes to Rs. 72,000/-   Approximate Quantity Method Estimate: In this method approximate total length of walls is found in running metre and its total length multiplied by the rate per running metre of wall gives a fairly accurate cost. For this method the interior may be divided into two parts viz.  The structure  The interior The running metre cost for structure and the interior should be calculated first and these running metre rates should be multiplied by the total length of the walls. To find the running metre rate for the interior, the approximate quantities of items such as woodworks, floor finishing, tiling etc. are calculated per running metre and by multiplying by the rates of these items the price or rate per running metre is determined. For this method the plan or line plan of the interior should be available.   Detailed Estimate or Item Rate Estimate: Detailed estimate is an accurate estimate and consists of working out the quantities of each item of works, and working the cost. The dimensions, length, breadth and height of each item are taken out correctly from drawing and quantities of each item are calculated, and obstructing and billing are done. The detailed estimate is prepared in two stages: - 1. Details of measurement and calculation of quantities-The details of measurements of each item of work are taken out correctly from plan and drawings and quantities under each item are computed or calculated in a tabular form named as Details of Measurement Form as follows. 2. Abstract of Estimated Cost: - The cost of each item of work is calculated in a tabular form from the quantities already computed and total cost is worked out in abstract of Estimate Form as shown below. The rates of different items of work are taken as per schedule of rates or current workable rates or analysed rates for finished items of work. A percentage usually 3% of the estimated cost is added to allow for work and a percentage of about 2% is provided for work charged establishment. The grand total thus obtained gives the estimated cost of the work. The detailed estimate is usually prepared work-wise, under each sub work. The detailed estimate is accompanied with: -  Report  General Specifications  Detailed Specifications  Drawings – Plans, elevation, Sectional elevation. Detailed drawings, Layout  Plan, etc.  Calculation and Designs –  Analysis of rates, if rates are not as per schedule of rates or for the non – scheduled items. Detailed Estimate is prepared for technical sanction of the competent authority, for arranging contract and for the execution of work.   Revised Estimate: Revised Estimate is a detailed estimate and is required to be prepared under one of the following circumstances:  When the original sanctioned estimate is exceeded or likely to exceed by more than 5%  When the expenditure on a work exceeds or likely to exceed the amount of Administrative sanction by more than 10%  When there are material deviations from the original proposal, even though the cost may be met from the sanctioned amount. The revised estimate should be accompanied by a comparative statement showing the variations of each items of work, its quantity, rate and cost under original and revised, side by side, the excess or saving and reason for variation.  Supplementary Estimate Supplementary Estimate is a detailed estimate and is prepared when additional works are required to supplement the original works, or when further development is required during the progress of work. This is a fresh detailed Estimate of the additional works in addition to the original estimate. The Abstract should show the amount of the original estimate and the total amount including the Supplementary amount for which sanction is required. Supplementary and Revised Estimate: When a work is partially abandoned and the estimated cost of the remaining work is less than 95 percent of the original work, that is less than 95 percent of the original sanctioned estimate, or when there are material deviations and changes in the design which may cause substantial saving in the estimate, then the amount of the original estimate is revised by the competent authority. A supplementary and Revised Estimate is then prepared and fresh Technical sanction of the competent authority is obtained. If at any time either before or during the execution of original work, it is found that the original estimate is excessive, and then Divisional officer may sanction a revised estimate of reduced amount. While giving such sanction the Accountant general and other higher authorities are informed.  Annual Repair or Maintenance Estimate (A. R. or A. M. Estimate): Annual Repair or Annual Maintenance Estimate is a detailed estimate and is prepared to maintain the structure or work in proper order and safe condition. For building; this includes white washing, colour washing, painting, minor repairs etc. further, there may be special repair estimate, Monsoon damage repair estimate, etc. Contingencies: The terms „Contingencies‟ indicates incidental expenses of miscellaneous character which cannot be classified under any distinct item sub-head, yet pertain to the work as a whole. In an estimate a certain amount in the form of contingencies of 3 per cent to 5 per cent of estimated cost, is provided to allow for the expenses for miscellaneous petty items which do not fall under any sub head of items of work. Miscellaneous incidental expenses which cannot be classified under any sub head or item are met from the amount provided under contingencies. If there is any saving against the amount provided under contingencies, this amount may be utilized with the sanction of the competent authority, to meet the expenses of extra items of work, if any unforeseen, expenditure, expenses to minor changes in design, etc.   General principle of approximate method of costing: There are various methods by which approximate estimates of an interior can be prepared. But in the general principle, they all consist of multiplying the number of items and units in the proposed structure by the known cost of a similar item or unit in a similar existing interior. Thus, it is a simple process involving two operations:  Fix up the unit and count the number of such units in the proposed work.  Fix up the unit cost by studying the actual cost of similar existing structure constructed in near past. If it becomes necessary to change the actual unit cost due to variations in construction costs, the same can be carried out with the help of a simple device known as cost index. It is a device which shows the relative changes in the cost of specific or group of items over a certain period of time. Following is the procedure of preparing the cost index:  The base period is selected  The critical items comprising the index are decided  Weight is assigned to each item  Periodic unit prices are collected  Approximate Methods of Costing For Various Interior Works The approximate cost of an interior work can be found out by the use of any one of the following five methods: 1. Service – unit method 2. Square – metre method 3. Cubic – metre method 4. Typical – bay method 5. Approximate quantities method The methods are arranged in degree of accuracy, i.e., the first method takes the least time and the results are very approximate while the last method takes more time than any other method but the results are more accurate. We will now discuss all these methods in detail. 1. Service-unit method: The service unit method indicates the most important unit in an interior work for e.g. in the interior work of a school building, the service unit is a class room; in a hospital, it is bed; in a large apartment, it is tenement; in a cinema, it is seat; in a prison, it is cell; in a stable, it is animal; in a hotel, it is room; in an office building, it is room; in a stadium, it is seat. Then, Approximate cost of an interior work = Number of service units in the interior work x Cost of corresponding service unit in a similar existing interior work. For instance, suppose an interior work of a school building of 16 classrooms is to be renovated and further let us assume that the cost of renovation of a classroom in a similar existing school building is Rs.20, 000. Then the approximate cost of the proposed interior work of a school building would be 16 X Rs.20, 000 or Rs. 3,20,000. Following points are to be noted: a. The estimates prepared by this method vary considerably according to the types of construction and standard of finish. b. The estimates prepared by this method are very approximate in nature. c. The proposed interior work should resemble the existing structure practically in all respects, so as to bring its approximate cost nearer to its true cost. d. Change of price- level of different items of interior work should also be taken into account while finding out the approximate cost of a proposed interior work.  By service-unit method, the approximate cost of a structure can be easily worked out and it takes less amount of time than any other method.  2. Square – metre method: - In this method, the area of each floor in the proposed building is worked out in square metres. Then, approximate cost of the proposed building interior = Total area of all the floors X Cost per square metre of a similar existing interior work. For computing floor area, measurements are taken out to out of walls and generally no deductions are made for stairways or similar other gaps. For working out plinth area, the projections at plinth level are excluded. Following factors affect the approximate cost worked out by this method:  Change of price level: Naturally, if the price level has changed considerably, cost per square metre of the existing interior should be suitably modified so as to accommodate this change of price level.  Ceiling height: In this method, height of the floor is not taken into account. Hence, if the height of the proposed interior work is to be more or less than the existing one, the cost per square metre should be slightly raised or lowered accordingly.  Type of construction: The type of construction and the standard of finish of the proposed interior work should be nearly the same as that of the existing one. This will bring the approximate cost of the building very near to the actual final cost.  Shape of the interior work: It is clear that interiors in square buildings will cost less per square metre than the rectangular ones of the same area. This is due to the fact that the square buildings have fewer perimeters of walls than that of the rectangular buildings of the same area. For instance, suppose there are two building interior – a square one of size 10m X10m and a rectangular one of size 20m X 5m. The areas of the two building interiors are the same, namely 100 sq. m. But the perimeter of walls in case of square building interior will be 40 metres while it will be 50 metres in case of rectangular building interior. Thus cost of rectangular building interior will generally be more than the cost of square building interior.  Large openings: If there are large openings in the floors, suitable adjustments should be made in the cost per square metre.  Location of the building interior: The similar existing interior, whose cost per square metre is to be taken to arrive at the approximate cost of the proposed building interior, should be similarly situated to the proposed building, as it will be absurd to compare two buildings situated far away from each other. 3. Cubic – metre method:- In this method, cost per cubic metre is used as a base for finding out the approximate cost of the proposed building interior. Cubical contents of the proposed building interior are worked out and then: Approximate cost of proposed building interior = Total cubical contents of proposed building interior X Cost per cubic meter of a similar existing interior. Measurements of the area are taken as in case of previous method and then this area is multiplied by the height of floor so as to get the cubical contents of the proposed building interior. All the factors mentioned in the previous method affect the approximate cost worked out by this method. Following few more points require further attention:  There is no general agreement regarding the inclusion of cubical contents of open verandas, open porches, plazas, etc. in the total cubical contents of the proposed building interior. Some estimators include them while others do not.  There is no general rule for measuring the height of the proposed building interior.  Great care should be taken in fixing the cost per cubic metre for the proposed building interior. It should be decided from the records carefully preserved for interiors of a similar nature.   To obtain satisfactory results with the help of this method, it is absolutely necessary to employ the same person to fix the cost per cubic metre and also to calculate the cubical contents of the proposed building interior. If the cost per cubic metre is decided by one person and cubical contents are calculated by another person, the results obtained are quite likely to be wrong and misleading. 4. Typical – bay method: This method is useful in case of interiors which have several similar bays. A bay is a space from centre to centre of two successive columns. A typical interior bay is selected and its total cost is worked out. Then, Approximate cost of proposed interior = Number of bays in the proposed interior X cost of one bay. Following points are to be noted:  Necessary correction should be made for the end bays due to end walls and also in other bays, if there is any difference in framing.  This method is useful for factories and such similar interiors.  More time is required by this method than any other previous method. But the result obtained by this method is found to be more reliable. 5. Approximate quantities method: In this method, various quantities are worked out with the help of many shortcuts. For instance wall panelling are measured in linear measurements, i.e., in running metres. The approximate quantities of items such as partitions, panelling, and water proof treatment are computed per running length and with the help of rates of these items; a fairly accurate price per running metre is built up. This price when multiplied by the total running measurements give the approximate cost of the building interiors required. Following points are to be noted:  The grouping of items and fixing their approximate price depend mainly on the experience of the estimator.  In this method, sufficient allowance should be made to compensate for the small things that are over-looked.  Out of all the previous methods, this method gives an estimate which is very near to the final estimate. It requires more time. But the results are quite satisfactory.  PROBLEM 1: A person purchases a building and renovates the portion of plinth area of 100 sq. m. in this building. The renovation cost is Rs. 28,000/-. The height of the building up to top of floor is 3.40 m. A parapet wall of height equal to 80 cm. is constructed on the terrace. Work out the cost per sq. m. and cu. M. of the interior. If a similar interior of plinth area equal to 140 sq. m. is to be renovated in nearby locality, what would be its approximate cost of construction? SOLUTION: Cost per sq. m. = 28000 =Rs. 280/- 100 For finding out the cost per cu. M., a suitable height is to be worked out. There is no general rule for fixing this height. In this case, the height of the building is measured between 20 cm below plinth level to centre of parapet wall. Height of the building = 0.20 + 3.40 +.5 x 0.80 =4.00 m Cubical contents = 100 x 4.00 = 400 cu. M. Therefore, cost per cu m = 28000 = Rs. 70/- 400 Plinth area of the similar interior =140 sq. m. Therefore, Cost of renovation = 140 x 280= Rs. 39200/- Cubical contents of the similar interior =140 x 4 = 560 cu. M. Therefore, cost of renovation = 560 x 70= Rs. 39200/-  Specifications Introduction The drawings of an interior project will show the shape, size, proportions and relative positions of its various components. It is not possible to furnish the details regarding the quality of materials and the workmanship of each and every item of the work on the drawing itself due to shortage of space. Hence this information regarding the quality of materials and the workmanship or the method of completing works, tools and plants to be used etc. details are conveyed in a separate contract document which is known as the specifications of the work. Thus, it is intended that the combination of the drawings and specifications will completely define the interiors, physically as well as technically. Objects of Specifications The specifications of the work are mainly written for the following objects:  The specifications clearly define the quality of the materials, the workmanship desired and the method of doing the work. Subsequently it enables the contractor who is filling the tender for the work to put correct rates for the different items of the work.  As detailed information is provided by the specifications regarding the materials and the workmanship, it serves as a guide to the contractor as well as to the supervising staff, during the construction and execution of the work.  The main object of the specification is to state the information which the engineer wants to convey so as to fulfil the needs of his design. The ideal specification framed by the engineer aims to protect the owner from any damage due to bad workmanship or low quality materials and at the same time, provides maximum freedom to the contractor to perform the work so as to turn out a satisfactory end product.  As the specifications provide details regarding the quantity of materials, the contractor can arrange the same n time and complete the work within scheduled time.  As the cost of work directly depends on its specifications the specifications give correct idea about the estimated cost, and funds can be arranged accordingly. Importance of Specifications Drawings and specifications form two important contract documents. Information (such as dimension, construction types etc.) which can be easily expressed graphically is put up on the drawings. On the other hand, instructions which can be expressed well in writing are written in the specifications. But generally the provisions in the specifications are given more legal strength and most of the contracts state that in case of discrepancy between the drawings and the specifications, the provision of the specification shall govern. Types of Specifications The specifications are broadly classified into two categories- a) Brief specifications b) Detailed specifications Brief specifications: - While preparing the estimate, the quantity surveyor writes down the brief description of every item, which is known as brief specifications. These specifications do not form a part of the contract document. These brief specifications are only useful to the person preparing the estimate of the work. Detailed specifications - These give detailed information regarding the quality of material and workmanship and form a part of the contract document. The detailed specifications can be further classified as follows: i. General provisions ii. Technical provisions iii. Standard specifications i. General provisions- These are also known as general conditions of the contact and they apply to the work as a whole. In this document, the conditions governing the contract are written. ii. Technical provisions - These specifications describe the technical requirements of each type of construction. The technical provisions contain detailed instructions regarding the desired quality of the final product or items. These provisions also provide for the inspection and the tests, which shall be done during the construction to make sure that the specified requirements regarding the quality of materials and workmanship are being obtained. However, while framing the technical provisions, it should be observed that they are in accordance with the provisions in the drawings of the work. These provisions are of three types:  Specifications for materials and workmanship  Specifications for performance  Specifications for propriety commodities   Specifications for materials and workmanship-These specifications are prepared to have a rigid control over the quality of materials and workmanship. For materials, the following properties should be included in the specifications: a) Chemical composition of the material b) Physical properties such as strength, hardness etc. c) Electrical, thermal and acoustical properties d) Appearance of the material e) Precautions regarding protection during transport, storage and handling etc. f) A clear statement regarding the inspection and procedure of test of the material. Also the place of the inspection and test should be clearly specified in the specification. For the control over the quality of workmanship following important features should be included in the specifications: 1. Detailed description of the construction method for each item should be written 2. Instructions regarding the protection of the of the finished work as well as of the adjacent property should also be specified. 3. Details of the result desired keeping in view the practical limits of the tolerances.  Specifications for performance - These specifications are based on the overall performance of the finished product and hence they describe about the equipments and machinery used in the interior work. The principal features included in these specifications are as follows: 1. General description: A complete idea regarding size, shape, etc. of the equipment or machinery for which the specification is meant should be provided to the contractor in a general way. 2. Design and installation: If the equipment required is desired to be of a particular design, the same should be specified. The main contractor usually installs the minor machinery himself, but in case of large machines, a turbine, a heavy crane etc. the owner invites separate tenders and enters into a separate contract. In the latter case, the specification should clearly state the final responsibility of erection and installation of the equipment and it should also state the facilities to be obtained from the main contractor. Moreover, the specification should also provide for the coordination of the machinery installation with the rest of the work.  3. Provision for special equipment: The detailed design of the equipment should be clearly stated in these specifications if the equipment is of a special type. The practice normally followed in such cases is to specify the type, power, capacity, efficiency, etc. of the special equipment and to ask the contractor to choose design of the special equipment. 4. Guarantee: The specification should also provide for the period of guarantee from the contractor for the performance and durability of the equipment.  Specifications for proprietary commodities: - These specifications include commercial products which are standardized or patented. As there is no control over such materials, hence it becomes essential to know exactly the quality of the product beforehand. Door, window fittings, timber, plywood etc. materials are the examples whose specifications are given. Hence, only thing to be mentioned in this type of specification will be to state a name of a particular brand or firm. However, it is not desirable to specify certain trade names or brands in some cases, due to the following reasons- 1. A monopoly is created for the patented article 2. A doubt of favouritism is laid on the officer writing the specifications 3. It is possible that some other manufacturers may be able to supply the same article of better quality at a lesser cost Hence to avoid such difficulties, one of the following clauses is added in these specifications-  It is a general practice to specify the selected brand and then it is followed by the phrase “or equal”. But when a substitute is proposed by the contractor it is very difficult to determine equality, and he becomes a subject of criticism by the manufacturers and the contractors. Also, if two substitutes of equal quality but of different prices are available, it becomes a matter of dispute between the owner and the contractor. To avoid all such complications, this phrase of “or equal” is not used at present, except for minor items.  A clause is inserted in the general conditions of contract, stating that, if the contractor desires to use products other than the specified ones, he should clearly state this fact in his tender and he should also state the adjustment to be made, if his substitute is approved by the owner while accepting the tender. The same procedure can be adopted when the work is in progress. But in this case the decision on substitutes will be taken by the engineer in charge of work. iii. Standard specifications: Specifications are seldom written completely for all items of the work. Usually the specifications are standardized for most of the items occurring in works of similar nature. Hence each office develops its own standard specifications in due course. These standard specifications are numbered. After standardizing the specifications, it is not necessary to write detailed specifications with all the contract bonds. While writing the contract bond only the serial numbers of the standard specifications are written. This saves lot of time, labour and stationery expenditure. Thus standard specifications save the lengthy process. Following points are to be noted in this connection: a) Extreme care should be taken to verify that the reference made to standard specifications is really suitable to the particular work to be executed. b) It is a general practice to provide blank spaces in the skeleton of the standard specifications for variable requirements. Therefore these blank spaces should be suitably filled up before accepting the standard clauses as specifications. c) The standard specifications when accepted for a particular job should be watched carefully and suitable additions, alterations, improvements or corrections necessary should be noted so as to include all such changes while using the same specifications for the next job of similar nature. d) These specifications are prepared by the government or manufacturers of materials or professional bodies. Individual manufacturers sometimes maintain a research staff to prepare specifications for their certain products. Such specifications are sometimes exaggerated just to make some products popular and hence, care should be taken to accept such specifications. However, specifications of reputed firm are reliable. e) Standard specifications should be periodically revised to include changes in techniques. Therefore, while including a reference to standard specifications in a particular contract, its edition with date of issue, title etc. should invariably be mentioned. f) Advantages of standard specifications are manifold. Processes are standardized resulting in simplified field control and in case of manufacture of materials; costs are reduced due to standardization of production methods. Products are also improved due to research on a cooperative basis. Principles of Specifications The specifications of the work are written by the engineer before it is known who the contractor will be. It should be noted that the technical knowledge of the engineer is of little value as far as writing of the specifications is concerned unless he can make his ideas clearly understood by the other contractors, workman, supervisor etc. many of whom may have little or no technical training. Some of the essential principles of good specification writing are as follows: 1. Subject matter: There should be a relation between the subject matter of the specifications and the information required after the contract is given to a particular contractor. Only the requirements which are to be enforced should be included in the specifications. Cross-reference use should be reduced to minimum. 2. Grammar: The rules of grammar should be applied to all sentences of the specifications. The style and tense should remain the same throughout. Hyphens, commas and semicolons should be used as and when required and the sentence should be framed in such a way that the addition, omission or misplacement of a comma does not alter the sense. As far as possible, the pronouns, especially relative pronoun, should not be used. It is advisable to repeat a noun. 3. Selection of words: Only suitable words with desired meaning should be used while writing specifications. Unfamiliar words or words having more than one meaning should never be used in the specifications. Also, use of unusual technical and trade expressions should not be made. 4. Accuracy: Care should be taken to see that the information is not repeated in the specifications. Also, the information given in the specifications should be complete and correct, otherwise the contractor may claim for any extra cost due to damage occurred to him by the misleading information supplied by the owner. 5. Conflicting requirements: The clauses of the specifications should be framed in such a way that no conflicts of any type result. 6. Practical limits and commercial size: The specifications should be framed while keeping in view the practical limitations of materials and workmanship and they should not specify practical impossibilities. Also, the use of commercial sizes and patterns of the material should be specified in the specifications. It is expensive to manufacture special sizes it also takes more time to prepare such sizes. For instance, steel sections and steel bars are readily available in certain sizes only. If other size is specified, a special order is to be given which requires more time and special rate for its delivery. 7. Clearness: As far as possible, the specifications should be clear and it should be observed that their meaning is not left to the engineer. In fact the same sense should be followed by both the parties – owner and contractor. Also, the specifications should state what the contractor shall or shall not do and not what the contractor should or should not do. 8. Fairness: The specifications should be fair and they should not be framed in such a way so as to throw all the risk on the shoulders of the contractor. Also, the specifications should specify all likely hazards, difficulties, etc. so as to give a clear picture of the work to the contractor. Unfair specifications are not desirable and sometimes they prove to be expensive in the sense that a contractor will assume all such risks and will put a higher price in his tender to accommodate all such risks, in case they come up. 9. Brevity: The specifications should contain short, simple and concise sentences. This is essential as the main purpose of the specifications is to give directions to the contractor and the supervising staff in carrying out the construction work. As straightforward specifications would be clearly understood by the persons filling the tenders, it may result into lower cost and early completion of the work. Also as specifications are a legal document, fewer words will involve less risk of legal difficulties. Brevity is the essence of the specification.  Typical Specifications Specifications of some of the common terms are given below. The points to be included in each specification are given in the beginning so as to draw an outline of the required specification. Hopefully, after carefully reading these typically specifications, the reader will get enough practice to form specifications of any other item. Specifications for brickwork I class in c.m. (1:6): Bricks shall be well burnt; table moulded, in approved kiln, free from cracks and with sharp and square edges. Bricks shall be uniform in shape and square edges, of standard sizes and shall give clear ringing sound when struck with each other. Bricks shall be well soaked in water for at least 12 hours before their use, preferably in a tank provided at site of work. The mortar shall be prepared in the proportion of one part of cement to six parts of sand by volume. Standard quality of cement shall be used and sand shall be coarse and clean. Prepare cement mortar in the required quantity of not more than one bag of cement at a time and it should be kept in mind that this quantity that is consumed within half an hour of mixing. While preparing mortar water fit for drinking shall be used. The mixing of mortar shall be done on a watertight platform or a steel trough. Use of broken bricks shall be prohibited except as closers. All corners shall be truly in plumb and sides shall be in line and level. There should be a break in mortar joints for bonding and shall not exceed 10mm in thickness. Employ only skilled labour on the work and the work shall be kept well-watered for at least 15 days. All brickworks shall be carried out in such a way that no portion is raised unduly above another. The length and height shall be measured as on at site. The thickness of walls shall be paid for as one brick, one and a half bricks, and two bricks and so on. The rate of brickwork includes necessary scaffolding also. Specification for timber doors and windows: It should be kept in mind that timber to be used shall be of the best quality, well-seasoned and free from cracks, knots, flaws, shakes and other defects. The rate for doors and windows includes fabricating and fixing in position of doors and windows. The shutters shall be prepared from scantlings 40mm in thickness as per design supplied. The shutters can be fully panelled or fully glazed or partly panelled and partly glazed as per the design supplied. The thickness of the panels shall be 20mm. The frames for doors and windows shall be of 10cm x 80mm size and they shall be provided with M. S. holdfasts of section 30mm x 6mm and of length 20cm. Three numbers of such holdfasts shall be provided on each side of the door frame and two such numbers of the holdfasts shall be provided on each side of the window frame. The sides of the frame abutting to the brick walls shall be coated with chocolate paint or coal tar. The workmanship of timber shall be of the best quality and only skilled carpenters shall be employed on the work. If any undue shrinkage or bad workmanship is found out afterwards, the contractor at his own cost shall repair the same. The rate for timberwork includes all the required fastenings and fixtures which shall be of brass and of approved quality, design and make and they shall be fixed as directed. The rate of timberwork includes three coats of oil paint of approved make and tinge. The measurements of the work shall be taken overall including frames and no extra amount shall be paid for any wastage of the material. Specifications for bricknogged partition in c.m. (1:3): Bricks shall be ground moulded, well burnt in approved kiln, copper coloured, free from cracks and with sharp and square edges. Bricks shall be uniform in shape and shall be of standard size and shall give clear ringing sound when struck with each other. Bricks shall be well soaked in water for at least 12 hours before their use, preferably in a tank provided at site of work. The proportion of mortar shall be one part of cement to three parts of sand by volume. Cement shall be of standard quality. Sand shall be clean and coarse. Prepare cement mortar in the required quantity of not more than one bag of cement at a time and it should be kept in mind that this quantity is consumed within half an hour of mixing. While preparing mortar water fit for drinking shall be used. The mixing of mortar shall be done on a watertight platform or a steel trough. Timber used for preparing the framework shall be of the best quality, well-seasoned and free from cracks, knots, flaws, shakes and other defects. The overall height of the timber framework shall be 2metres and it shall consist of head, sill studs and noggin pieces. The section of head, sill and studs shall be 10cm x 10cm. Two noggin pieces of section 10cm x 12mm shall be provided. The studs shall be provided at a centre-to- centre distance of 90cm. The surfaces of timber framework coming in contact with the masonry shall be coated with coal tar. Broken bricks shall not be used except to create a bond. Mortar joints shall break for bending and shall not exceed 12 mm in thickness. Only skilled masons shall be employed on the work and the work shall be kept well watered before plastering is commenced. The rate of bricknogged partition includes 12mm thick cement plaster of sagol finish and three coats of white or colour wash on both the surfaces of the partition. The items of plaster and white or colour wash shall be carried out as per specifications contained in this document. Sufficient number of nails shall be fixed on the timber framework to provide foundation for the plaster. The payment shall be made for the actual superficial area covered and no extra amount shall be paid for wastage of materials, etc. Specifications for terrazzo finish: The marble chips to be used for terrazzo work shall be approved shade and make. The chips shall vary in size from 30 mm to 60 mm. The first coat for terrazzo work shall be of cement mortar 1:3, i.e., one part of cement to three parts of clear, coarse, river sand by volume. Mixing of mortar shall be done on a watertight platform or in a steel trough. Mortar of one cement bag shall only be prepared at a time and the same shall be consumed in half an hour after mixing with water. The thickness of first coat shall be 12 mm. The surface of the first coat shall be kept rough by providing zigzag lines and it shall be well watered for at least 7 days. The terrazzo mix for second coat shall be prepared in proportion 1:3, i.e., one part of cement to three parts of marble chips by volume. The cement and the marble chips shall be thoroughly mixed in dry condition and then sufficient quantity of water shall be added so as to get a plastic mixture. This terrazzo mix shall be uniformly applied on the first coat and its thickness shall be 6 mm. The polishing of terrazzo shall be done after three days of completion of second coat and during this period also, the surface shall be kept wet. The process of polishing shall be carried out in three coats. The first coat of polishing shall be done by means of a coarse carborundum stone and water shall be freely used during this operation. Any patches found during this process shall be repaired with the help of original terrazzo mix. After 5 days from the completion of first coat of polishing, the second coat of polishing shall be done by means of a finely grained carborundum stone. Then wax shall be applied as final coat of polishing after making the surface completely dry. The measurement shall be taken for the actual superficial area and no allowance shall be given for wastage, etc. Specification for pointing in c. m. (1:1): The pointing work shall be started as soon as brickwork is completed. The joints shall be raked out to a depth of 20mm and the surface of the wall shall be cleaned, washed and well watered at least for two days. The mortar shall be prepared by mixing equal volumes of cement and sand. The cement shall comply with standard requirements and sand shall be clean, fine and free from organic impurities. The materials shall be thoroughly mixed in dry condition before water is added to them. The mixing shall be done on a water tight platform and mortar of one cement bag only shall be prepared at a time which shall be consumed within 30 minutes after adding water. The mortar shall be placed in the joints in the best workmanship manner. The extra mortar shall be removed so that the edges of bricks shall be clearly defined. The finished surface shall be kept well watered at least for 10 days. The payments shall be made on superficial contents. Specifications for 20 mm sand faced cement plaster: The work of sand faced cement plaster shall be carried out after masonry joints are raked out to a depth of 20 mm and the walls are well- watered. The first coat of sand faced cement plaster shall be of cement mortar of proportion 1:4, i.e., one part of cement to four parts of clean, coarse and angular river sand by volume. Mortar of one cement bag shall only be prepared at a time and it shall be prepared on a watertight platform or in a steel trough. The mortar shall be consumed in 30 minutes after adding water. The first coat of plaster shall be uniformly applied in the best workmanship manner after watering the surfaces of walls in advance and putting dots and preparing screeds for maintaining uniform thickness of plastered surface. The thickness of first coat shall be nowhere less than 12 mm. The first coat shall be well watered at least for 7 days. The first coat shall be provided with zigzag lines such that the first coat adheres well with the second coat. The second coat of sand faced cement plaster shall be carried out in c.m. of proportion 1:1 and shall be of thickness 8 mm. The second coat shall be applied on the first coat at least after 7 days of completion of first coat. The second coat shall give uniform grey colour to the whole structure or any other colour as approved by the engineer. Sand to be used in the mortar for the second coat shall be perfectly screened so that sand of uniform size shall appear on the surface. Sponge shall be used in the second coat and it shall be applied when the second coat is wet and it shall be so worked that the density of sand grains appearing on the surface shall be equal and uniform. After completion of second coat, the surface shall be kept well-watered at least for 15 days. The payment shall be made for superficial area covered. Specification for whitewashing in three coats: Walls to be whitewashed shall be cleaned before the work is started. Fresh white lime shall be slaked at site of work and shall be mixed thoroughly with sufficient quantity of water in a tub and shall than be screened through a clean cloth. Clean gum or rice dissolved in hot water shall be mixed with lime in required quantities. The whitewash shall be applied with jute brush and the brush shall be so worked that a surface with uniform colour is obtained. Three coats shall be applied; each after the previous coat has completely dried. The strains of whitewash on the floor or other surfaces shall be removed. The payments shall be made on superficial contents and openings shall be deducted once only to compensate for tops, bottoms and sides of the openings. Specifications for painting in three coats: The surface to be painted shall be cleaned and made smooth by rubbing sand papers of different grades. In case of steel work, dust and scales shall be thoroughly removed. The paint to be used shall be approved tint and make. Pure turpentine shall be used as a thickening agent. A priming coat shall first be applied and then all cracks, holes etc. shall be filled with putty or with a mixture of glue and plaster of paris. The second coat of paint shall then be applied and after it has dried, the final coat of paint shall be applied. The paint shall be applied in the best workmanship manner. The brushes to be used shall be of the best quality and they shall be worked in such a way that a surface of uniform shade is obtained without any hair marks, drops of paints, etc. At the end of the day’s work, the brushes shall be cleaned by turpentine and shall be kept dry. Painting shall be paid in superficial contents. Doors and windows shall be measured flat on two sides and no extra measurement shall be taken for mouldings, etc. Gaps of grillwork shall be measured on one side only for painting both sides of grillwork. Half of the glazed part shall be deducted from the measurements of flat area. Louvers and Venetians shall be treated as one and a half times of the corresponding flat area. Specification for ashlar masonry in c.m. (1:3): The stones to be used on the work shall be hard, durable and tough and shall be of uniform shape. Minimum height of stones shall be 20 cm. The length of the stone shall not exceed three times its height and its depth into the wall shall be at least half of its height. The stones shall be chisel dressed on at least five out of six faces. The stones shall be wetted before placed in position. The proportion of mortar shall be one part of cement to three parts of sand by volume. Cement shall be of standard quality. Sand shall be clean and coarse. Prepare cement mortar in the required quantity of not more than one bag of cement at a time and it should be kept in mind that this quantity is consumed within half an hour of mixing. While preparing mortar water fit for drinking shall be used. The mixing of mortar shall be done on a watertight platform or a steel trough. Each course shall be made truly horizontal. All corners shall be truly in plumb and the sides shall be in line and level. Mortar joints shall break for bonding and shall not exceed 3mm in thickness. Only skilled workers shall be employed on the work. The finished work shall be suitably protected from sun, wind, rain, etc. and shall be kept well watered for at least two weeks after completion. The work shall be carried out in such a way that no portion is raised unduly above another. The payment of stonework shall be made on cubical contents. Length, width and height of walls shall be measured as on site. The rate for ashlar masonry includes necessary scaffolding also and no extra amount shall be paid for the same. Specifications for cast iron articles: The casting shall be sharp, clean and free from cracks, flows, air bubbles, blowholes, honeycombing or from any other defects. The casting shall give clear ringing sound when struck with a light hammer. The metal to be used shall be free from cinder or other inferior iron. The fracture of metal shall present a uniform diffused dark grey colour with pronounced lustre. Two samples of the cast-iron articles shall be submitted by the contractor to the engineer for ready reference and these samples shall be returned at the end of work. The rate of cast-iron articles includes fixing them in position and three coats of silver paint or anticorrosive paint. Specification for driving precast R.C.C. piles: Precast piles prepared from Portland cement shall be driven after six weeks of curing and if prepared from high alumina cement, they shall be driven after four days. All piles shall be driven in vertical alignment unless otherwise instructed by the engineer. If piles are 50 mm out of their position, such repairs as recommended by the engineer shall be carried out by the contractor without any extra cost. The piling machine shall be of sufficient power and efficiency and shall be steam driven. The weight of ram to be used shall be decided by the engineer, depending on the type of piles. The drop of ram shall not exceed 2metres in any case. The pile-heads shall be protected by an approved cap of C.I. or steel plate during driving. Bearing piles shall be driven to a set of 25 mm for eight successive blows of a 2 tonne hammer whose free fall is one metre or such set as instructed by the engineer for each individual case. The payment shall be made for each length of metre driven Specification for providing and laying 15 cm diameter S.W. pipe:. The stoneware pipes shall be of the best quality, regular in size and shape, free from flaws, cracks and glazing blowholes. The internal and external surfaces of the pipes shall be smooth and perfectly glazed. The stoneware pipes shall be able to resist a bursting pressure of 2 kg per square cm without showing any signs of leakage. The thickness of stoneware pipes shall not be less than one-twelfth of the internal diameter of the pipe. The trench for laying the pipe shall be excavated as per levels given and no pipes shall be laid until a distance of 15 metres is excavated and prepared completely to receive the pipe. The stoneware pipes shall be laid true to the invert level. The spigot of the pipe shall be carefully adjusted in the socket of the pipe previously laid. The joint shall then be finished with the help of a ring of rope yarn dipped in liquid mortar. The joint shall then be filled with c.m. of proportion 1:1. Each joint shall be neatly cleaned off. The line laid shall be tested for leakage by plugging one end and allowing water to flow from the other end under a head of 150cm. The trench shall be kept free from water before this test is made. Leaking joints shall be repaired by the contractor. The refilling of the trench shall be started after getting written permission from the engineer. The refilling of the trench shall be done in layers of 30 cm and each layer shall be well watered. The payment shall be made for the actual length of pipe laid and the rate shall include excavation of the trench, laying and joining the pipes, refilling and spreading the surplus earth within 60 metres radius as per instructions of the engineer. Specification change format  Taking Out Quantities Objective: To understand the meaning of the term “taking out quantities” and its importance in the execution of an interior design work. To understand the methods used for taking out quantities. Structure:  Introduction  Essentials of an Estimator  Requirements of an Estimator  Methods of Taking out Quantities  English method of taking out quantities  Units of Measurements  Modes and Unit of Measurement For Different Types Of Trades  General rules for measurements Introduction The procedure in which the quantities of various items in a particular interior are worked out is known as „taking out quantities’. By studying in detail the drawings of the interiors these quantities are obtained. Hence an estimator should possess a thorough knowledge of reading the drawings and as a matter of fact he must be in a position to visualize the interiors even from its drawings. Unless unity is established between the mind and the drawings of the interiors, it is not possible to obtain the correct quantities of the various items. It should always be kept in mind that the accuracy should never be sacrificed for the speed. As a matter of fact, the secret of success of a good estimator is his ability to achieve speed with accuracy. Essentials of an Estimator The qualities of a good estimator are as follows:  He must possess good knowledge of mensuration and trigonometry.  He must possess thorough knowledge of construction methods and procedures, materials of construction, labour problems, specifications and local customs.  He must possess ability to read and interrupt drawings accurately and efficiently.  He must possess accuracy in calculations and costs.  He must possess excellent personal qualities such as common sense, skill, experience, initiative, foresight, good judgment and patience. Requirements of an Estimator Following are the requirements of a good estimator: 1. A complete set of detailed drawings; 2. Cost analysis file of works executed and difficulties experienced; 3. Detailed specifications; 4. Hand books for reference; 5. Labour wage records; 6. Price list of materials; 7. Scales to measure missing dimensions; 8. Schedule of rates, if any; 9. Trade circular file of literature on materials and equipments; etc. Methods of Taking out Quantities By establishing suitable conventions every country has developed its own method for taking out quantities. The aim is same but the ways are different. We will discuss, in brief, the method of taking out quantities followed by the English people but our own method, known as Public Works Department (abbreviated to P.W.D.) method of taking out quantities, will be adopted throughout. English method of taking out quantities: In English method, the following three processes are involved: 1. Taking off; 2. Grouping; and 3. Billing. Thus the quantities of the various items are worked out on a measurement or dimension form and then the quantities of identical items are grouped together and written on an abstract form. The measurement form is a full sized paper, double ruled. Column 1 is called the timesing column Column 2 is called the dimension column Column 3 is called the squaring column Column 4 is called the description column, in which, the brief description of the item is written. The right hand side of this column is used for rough work and is called waste. Units of Measurements Nature, size and shape determine the units of measurements of a particular trade of an interior work. The general principles for deciding the units of measurements for various items of work are as follows: 1. Cubical contents or cubical units are used for the items which are massive, voluminous and thick and which have considerable dimensions in all the three directions. 2. Area or square units are used for the items of work which are shallow, surface oriented and thin and which have one dimension difficult to measure. 3. The items of work which are long, narrow and thin and which have two dimensions difficult to measure precisely are measured in linear or running units. 4. The items of work which are difficult to be split into separate items and which are difficult to measure are measured in numbers or units. 5. Some of the items of steelwork which require special technique in construction are measured in weight units. Modes and Unit Of Measurement For Different Types Of Trades The standard modes of measurement for some of the most common items are given below- 1. Preliminaries: These are the items such as demolishing the existing structure etc. Normally, such items are paid on a lump sum basis. But if the demolishing work consists of brickwork, it is possible to work out the cubicle contents and in such cases; the actual measurements of work to be demolished are taken. The unit of measurement is cubic metre. 2. Concrete: Plain cement concrete work is paid in cubic metres.  R.C.C. stair is measured in terms of number of steps. Quarter and half landing are considered as equivalent to two and four steps respectively.  Damp proof course is measured in square metres and the depth of the course is specified.  Precast cement concrete jalli work or louvers are measured in square metres and the thickness is specified. 3. Brickwork: The half brick partition wall and the walls having thickness less than half brick are measured in square metres. It should be noted that while taking measurements of the brickwork, walls are treated as solid walls without any openings. But after the measurements are completed, deductions are made for doors, windows, ventilators etc. 4. Stonework: The specification should give full description for the cut-stone work in steps, cornices, etc. The stonework for the shelves and slabs is measured in square metres. 5. Woodwork: The specifications should clearly mention the type of the materials used and the quality of finish required, in case of woodwork. The rate for any type of woodwork includes fabrication, fixation, fastenings, fixtures and three coats of oil paint. No consideration is given to the wastage of the material. However, 2mm tolerance is allowed. Frames for doors, windows, ventilators and cupboards are measured in cubic metres. Wooden door, window, ventilator, and cupboard shutters are measured in square metres. If the frames are not being measured separately, the overall dimensions including the thickness of the frames are recorded. Wooden trellis work is measured in square metres. Wooden stair is measured in terms of number of steps and the specifications define the type and width of stair. Wooden cornices, picture rails, shelves, architraves etc. are measured in running metres. 6. Plastering: Specifications define the thickness of the plastering and the type of mortar. Plastering is measured in square metres. Bands in plaster, having thickness of 30 cms or less, are measured in running meters. The following rules are generally followed for deductions:  If the quality of the plaster is the same on both the sides of the wall, openings in the wall are deducted once only and no measurements are taken for top, bottom and side of the openings.  If the two sides of the wall are provided with different types of plaster, one half of the area of the openings is deducted from each type of plaster.  The openings which are more than 3 square metres in area are to be deducted for two sides separately and the measurements for the top, bottom and sides of such openings are to be taken into account. 7. Pointing: Specifications mention the type of pointing and quality of the mortar. The measurements are taken of the whole flat surface in square metres. Deductions are made as per item of plastering. 8. Steelwork: Grillwork in windows is measured in square metres. Rolling steel shutters are paid per square metre of the opening covered or actual area of the shutters. Sometimes, they are paid per number and the size is mentioned. Steel doors, windows and ventilators are measured in square metres and the measurements are taken overall. The description of various members is given. Plain rolled sections, built up work, steel bars etc. are paid by weight in quintals. 9. Floor finishes: Measurement of floor finishes are taken in square metres for the net area covered. No extra amount is paid for wastage of the materials. 10.Whitewashing, colour washing and distempering: The items of white washing, colour washing and distempering are measured in square metres. Corrugated surfaces are measured flat and then a suitable co efficient is applied to compensate for the corrugations. Deductions are made as per item of plastering. 11.Painting: The item of painting is paid in square metres. The measurements are taken flat and then multiplied by a suitable coefficient to compensate for mouldings, rebates, corrugations, etc. Painting the work having width less than 15 cms is paid in running metres.  12.Water supply connections: The item of galvanized iron or cast iron pipeline is measured in running metres for the length laid and no extra amount is paid for the specials such as bends, tees, etc. The measurement is taken along the centre line of the pipeline. Bib – cocks, wheel valves, stop cocks, etc. are described in detail and paid per number. 13.Drainage connections: The item of the pipeline is measured in running metres for the actual length laid and no extra amount is paid for the specials such as bends, tees, etc. The measurement is taken along the centre line of the pipeline. Inspection chambers and manholes are paid per number and the specifications should give their full description. If the depth of the inspection chambers or manholes exceeds 6 metres, the measurements of various trades are taken separately. Gully traps, nahni traps, w.c. pans, flushing tanks, mica flap valves, etc. are paid per number and the specification should mention their quality, make, method of fixing, etc. General rules for measurements: Following are the general rules to be adopted for the measurements of various items of work: 1. The description of the items should be self-explanatory and it should include all materials, labour, transport, tools, plant, temporary formwork, etc. 2. The dimensions should be entered in the order of the length, breadth and depth or height or thickness. 3. The measurements for the same item of work under different conditions should be recorded separately. 4. The measurements should be for the finished item of work. 5. The method of measurement should be uniform. 6. The nomenclature of item of work should completely describe the materials, workmanship and method of execution.