Quantity Survey & Estimation – Lecture # 10

Quantity Survey & Estimation – Lecture # 10

Table of Content

    • Estimating in the Construction Industry
    • Types of Estimating
    • Estimating Opportunities in Industry
    • Qualities Needed for a Good Estimator

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Quantity Survey & Estimation – Lecture # 10 – Excerpt

Quantity Survey & Estimation

Course Instructor

Engr. Shad Muhammad

Lecturer, Department of Civil Engineering

Qurtuba University of Science & IT, D. I. Khan.

Review of Lectures till Mid Term

Lecture # 1: Procedure of Estimating + Rules & Methods of Measurement

Lecture # 2: Method of Building Estimates (Separate or Individual Wall Method)

Lecture # 3: Method of Building Estimates (Center Line Method)

Lecture # 4: Estimate of Arch Masonry & Masonry Steps

Lecture # 5: R.C.C Works & Structures (R.C.C Slab & Beam)

Lecture # 6: R.C.C Works & Structures (R.C.C Column, Foundation & Retaining Wall)

Lecture # 7: Analysis of Rate (Material-Concrete, Brickwork, Mortar)

Lecture # 8: Analysis of Material-(Plastering & Pointing), MRS-2016, Unit of Analysis

Content of Lectures after Mid Term

Lecture # 9: Estimating, Types of Estimates, Estimating Scope

Lecture # 10: Specifications for different classes of buildings & Civil Engineering Works

Lecture # 11: Roads & Irrigation Estimation

Lecture # 12: Valuation

Lecture # 13: Tendering

Lecture # 14: Preparation of Civil Engineering Contracts (Contract System, Contract Document, etc.)

Lecture # 15: Evaluation of Proposals & Contracts

Lecture # 16: BOC, Project Evaluation & Estimation, Contract Documents as per Pakistan Standards

Content of Lecture # 9, 10

Estimating in Construction Industry

Types of Estimating

Estimating Opportunities in Industry

Qualities Needed for a Good Estimator

Estimation in “Construction Industry

Building construction estimating is the determination of probable construction costs of any given project.

Because the estimate is prepared before the actual construction, much study & thought must be put into the construction documents.

The estimator who can visualize the project & accurately determine its cost will become one of the most important persons in any construction company.

For projects constructed with the design-bid-build (DBB) delivery system, it is necessary for contractors to submit a competitive cost estimate for the project.

Because the estimate is prepared from the working drawings & the project manual(Specifications) for a building, the ability of the estimator to visualize all of the different phases of the construction project becomes a prime ingredient in successful bidding.

Estimation in the Construction Industry

The working drawings usually contain information relative to the design, location, dimensions, & construction of the project, while the project manual is a written supplement to the drawings & wp-wp-includesss information pertaining to materials & workmanship, as well as information about the bidding process.

The working drawings & the project manual constitute the majority of the contract documents, define the scope of work, & must be considered together when preparing an estimate. The two complement each other, & they often overlap in the information they convey. The bid submitted must be based on the scope work provided by the owner or the architect.

The estimator is responsible for including everything contained in the drawings & the project manual in the submitted bid.

Because of the complexity of the drawings & the project manual, coupled with the potential cost of an error, the estimator must read everything thoroughly & recheck all items. Initially, the plans & the project manual must be checked to ensure that they are complete. Then the estimator can begin the process of quantifying all of the materials presented.

Every item wp-wp-includessd in the estimate must contain as much information as possible. The quantities determined for the estimate will ultimately be “used to order & purchase” the needed materials.

The estimated quantities & their associated projected costs will become the basis of project controls in the field.

Estimation in the Construction Industry

Estimating the ultimate cost of a project requires the integration of many variables. These variables fall into either direct field costs or indirect field costs.

The indirect field costs are also referred to as general conditions or project overhead costs in building construction.

The direct field costs are the material, labor, equipment, or subcontracted items that are permanently & physically integrated into the building.

Example: The labor & materials for the foundation of the building would be a direct field cost. The indirect field costs are the cost for the items that are required to support the field construction efforts. The project site office would be the cost of a general condition.

In addition, factors such as weather, transportation, soil conditions, labor strikes, material availability, & subcontractor availability need to be integrated into the estimate.

Regardless of the variables involved, the estimator must strive to prepare as accurate an estimate as possible.

Since subcontractors or specialty contractors may perform much of the work in the field, the estimator must be able to articulate the scope of work in order for these companies to furnish a price quote.

The complexity of an estimate requires organization, estimator’s best judgment, complete specialty contractors’ (subcontractors’) bids, accurate quantity takeoffs, & accurate records of completed projects.

Estimation in the Construction Industry

The design-build (DB) & construction manager (CM) project delivery systems are gaining in popularity.

In the design-build delivery system, the contractor acts as both the designer & the general contractor.

In the construction manager delivery system, the contractor is involved in the design process, providing expertise in construction methods & costs, as well as managing the construction process.

Both of these delivery systems require the contractor to provide cost estimates for the proposed project throughout the design process.

At the conceptual stage of the project, the contractor prepares a cost estimate based on the project’s concept. This is known as a conceptual estimate.

When performing a conceptual estimate, typically, drawings are not available or they are very limited. What exists is often a vague verbal or written description of the project scope, which may be accompanied by a few sketches. When preparing this type of estimate, the contractor makes assumptions about virtually every aspect of the project.

The conceptual estimate is used early in the design process to check to see if the owner’s wants are in line with their budget & is often used as a starting point to begin contract negotiations.

Estimation in the Construction Industry

During the design process, the contractor prepares & maintains a cost estimate based on the current, but incomplete, design. This is often referred to as a preliminary estimate.

In addition, the contractor may prepare estimates that are used to select between building materials & to determine whether the cost to upgrade the materials is justified.

What all these estimates have in common is that the design is incomplete. Once the design is complete, the contractor can prepare a detailed estimated for the project.

Types of Estimates

1.Preliminary Estimate (Or Approximate Estimate or Abstract Estimate or Rough Cost Estimate)

2.Plinth Area Estimate

3.Cube Rate Estimate or Cubical Content Estimate

4.Approximate Quantity Method Estimate

5.Annual Repair or Maintenance Estimate

6.Special Repair Estimate

7.Revised Estimate

8.Supplementary Estimate

9.Detailed Estimate Or Item Rate Estimate

Types of Estimates

10.Assembly Estimating

11.Square-Foot Estimates

12.Parametric Estimates

13.Model Estimating

14.Project Comparison Estimates

Types of Estimates
1. Preliminary Estimate

This estimate is prepared to decide financial aspect, policy & to give idea of the cost of the proposal to the competent sanctioning authority.

The data can be attained from a similar construction already complete in the nearby area, executed by the department.


To calculate the approximate estimate for a Hospital, per bed cost, is calculated from the recently completed hospital & is multiplied with the number of beds required.

For a House, per square meter plinth area is calculated & is multiplied with the proposed covered area. The specifications should also be same.

For a Road, the expenditure of per kilometer length is taken, width also plays the role.

The following documents should be attached with it.

  (a) Detailed report

  (b) Site plan of the proposal

  (c) It should also clearly mention about the acquisition of land & Provision of Electric & Water Supply etc.

Types of Estimates
1. Preliminary Estimate

The approximate estimate is prepared from the practical knowledge & cost of similar works.

The estimate is prepared showing separately the approximate cost of all important items of work e.g. cost of land & cost of Building, cost of transportation, water supply sanitary works, electrification etc.

This is also accompanied with a site plan or layout plan. A percentage of about 5% to 10% is added as contingencies.

Types of Estimates
1. Preliminary Estimate

The preliminary estimate may be prepared by various ways for different structures & works-


Per unit basis – per student for school & hostels, per class room for schools, per bed for hospitals, per seat for cinema.

Approximate cost of a hostel building for 100 students @ Rs. 10,000/- per student works out to be 10 lakhs.

Approximate cost of a 100 bed hospital @ Rs. 50,000/- per bed comes to Rs. 50 Lakhs.

Approximate cost of a two roomed quarter may be Rs. 60,000/- a three roomed quarter may cost Rs. 90 thousands.

Types of Estimates
1. Preliminary Estimate

Roads & Highways

Per kilometer (per mile) basis depending on the nature of the road. Width & thickness of metalling, etc.

For 10 Km of a state highway (Motorway or GT Road) approximate cost @ 5,00,000/- per 1 km works out as Rs. 50 Lakhs.

Irrigation Channels

Per kilometer (per mile) basis depending on the capacity of the channel.

Area of land commanded i.e., per hectare basis (per acre basis)

The approximate cost of 10 kilometer length of irrigation channel of 3 m3 per sec capacity @ Rs. 70, 000/- per km works out as Rs. 7 lakhs

For an irrigation project having a commanded area 2000 hectares, approximate cost @ Rs. 1000/- per hectare come to be Rs. 20 lakhs

Types of Estimates
2. Plinth Area Estimate

Plinth area of a building means Length x Breadth ( roofed portion only ) excluding plinth offsets.

The estimate is prepared on the basis of plinth area of the building.

Plinth area estimate is calculated by finding the plinth area of the building & multiplying by the plinth area rate.

The plinth area is calculated through calculating the covered area by taking external dimension of the building at the floor level.

Courtyard or other open area should not be wp-wp-includessd in the plinth area.

Plinth area estimate is only approximate, & is a preliminary estimate.

Types of Estimates
2. Plinth Area Estimate

Carpet Area: Refers to the total usable area within the four walls of an apartment or a commercial space, as the case may be. In other words, it refers to the area for which a carpet can be laid if required by the owners. 

Plinth Area: Refers to the entire carpet area along with the thickness of the external walls of the building. It obviously wp-wp-includesss the thickness of the internal walls & the columns, if any, lying within the four walls of an apartment. The commercial space is not taken into account in calculating the plinth area.

Plinth Area = Carpet Area + Area Covered by Wall

Types of Estimates
2. Plinth Area Estimate

If the plan of the building is not ready or available, then at the beginning prepare floor area of rooms, etc., may be determined from the requirements.

30 to 40 percent of the total area thus found may be added for walls, circulations & waste to get the approximate total plinth.

Plinth area which is multiplied by the plinth rate gives the approximate cost of the building.

The approximate cost of the building having a plinth area of 100 m2 @ Rs. 900/- per m2 =Rs. 90,000.

For storied building, the plinth area estimate is prepared for each storey building.

Example, if total cost of a building is Rs. 2 lac & its plinth area is 50 m2, then plinth area rate = 2,00,000/50 = Rs.4000/m2

Using this rate as basis of the next construction, approximate or rough cost of the proposal can be arrived at by multiplying the plinth area of the proposed building with this plinth area rate.

Types of Estimates
3. Cube Rate or Cubic Content Estimate

Cube rate estimate is a preliminary estimate or an approximate estimate, & is prepared on the basis of the cubical contents of the building.

The cubic contents of a building means plinth area x height of the building. The height is taken from top of floor level to top of the roof.

The cubic contents of the proposed building are multiplied with cubic rates arrived at for the similar construction i.e. total cost of construction divided by cubic contents = Cost/m3.

Cube rate estimate is more accurate as compared to the plinth area estimate as the height of the building is also compared.

The approximate cost of the building of cubic content (volume) of 400 m3 @ Rs. 180/- per m3 comes to Rs. 72,000/-

Types of Estimates
4. Approximate Quantity Estimate

In this method, the approximate total length of walls is found in running meter.

This total length multiplied by the rate per running meter of wall gives a fairly accurate cost.

For this method the structure is divided into 2 parts;

1.Foundation including plinth


These running meter rate should be multiplied by the total length of walls.

To find the running meter rate of foundation, the approximate quantities of items such as excavation in foundation, brickwork up to plinth, & DPC are calculated per running meter.

Multiplying by the rates of these items the price or rate per running meter is determined.

Similarly for super structures the price or rate per running meter is determined.

For this method the plan or line plan of the structure should be available.

Types of Estimates
5. Annual Repair Estimate

In order to keep building & roads in perfect condition, annual repairs should be carried out as follow:-

1)In case of a Building

  • White washing, oiling & painting of doors & windows, cement plaster repairs (inside & outside), repairs of floors etc.
  • In no case this annual repair amount should increase more that 1 ½ % to 2 % of the capital cost of the building.

2)In case of a Road

  • Filling patches, maintenance of berms etc.

Types of Estimates
6. Special Repair Estimate

If the work cannot be carried out of the annual repair funds due to certain reasons resulting in the genuine increase in cost, then special repairs estimate is to be prepared.

The reason of increase may be:-

  • In case of a building– opening of new doors, change of floors, re-plastering walls etc.
  • In case of roads– if the whole surface is full of corrugation & patches, then the total surface is to be scarified. The old metal is taken out, consolidation by adding more metal is done & top surface is repainted.

Types of Estimates
6. Revised Estimate

Revised estimate is a detailed estimate & is required to be prepared under any one of the following circumstances;

1.When the original sanctioned estimate is exceeded or likely to exceed by more than 5%.

2.When the expenditure on a work exceed or likely to exceed the amount of administrative sanction by more than 10 %.

3.When there is material deviation from the original proposal, even though the cost may be met from sanctioned amount.

Types of Estimates
7. Supplementary Estimate

The supplementary estimate is a detailed estimate & is prepared when additional work are required to supplement (add) to the original work .


When further development is required during the progress of the work.

This is fresh detailed estimate in addition to the original sanctioned estimate, prepared when additional works are deemed necessary during the progress of a work to supplement the original works.

The abstract of cost should show the amount of the original sanctioned estimate as well as the supplementary amount of the original sanctioned estimate as well as the supplementary amount for which sanction is required.

Types of Estimates
8. Detailed Estimate

The required level of accuracy coupled with the amount of information about the project that is available will dictate the type of estimate that can be prepared.

The detailed estimate wp-wp-includesss; determination of the quantities & costs of everything that is required to complete the project. This wp-wp-includesss materials, labor, equipment, insurance, bonds, & overhead, as well as an estimate of the profit.

To perform this type of estimate, the contractor must have a complete set of contract documents. Each item of the project should be broken down into its parts & estimated. Each piece of work that is to be performed by the contractor has a distinct labor requirement that must be estimated.

The items that are to be installed by others need to be defined & priced.

Caution needs to be exercised to ensure that there is agreement between the contractor & the specialty contractor as to what they are to do & whether they are to install or supply & install the items.

In addition, there needs to be an agreement about who is providing support items such as cranes & scaffolding.

Types of Estimates
8. Detailed Estimate

The contractor is responsible for making sure that the scope of work is divided among the contractor & subcontractors so that there are no overlaps in the individual scope of works & that everything has been wp-wp-includessd in someone’s scope of work.

The detailed estimate must establish the estimated quantities & costs of the materials, the time required for & costs of labor, the equipment required & its cost, the items required for overhead & the cost of each item, & the percentage of profit desired, considering the investment, the time to complete & the complexity of the project.

Types of Estimates
9. Assembly Estimate

This type of estimate can be prepared in hours instead of spending days preparing a detail estimate.

The trade-off is that this type of estimate has many broad assumptions & is less accurate. This type of assembly estimating is good for estimates prepared with limited drawings, to compare design approaches & as a check of a detailed estimate that seems way off.

If the assembly price comes from previously completed projects, it is assumed that this project is identical to the completed projects.

That assumption is clearly not valid in the construction of buildings. Weather conditions, building materials & systems as well as design & construction team members change from project to project, all adding to the uniqueness of every project.

Skill & judgment must be used while preparing this type of assembly estimate to ensure that proper adjustments are made by taking into account the varying conditions of each project.

Types of Estimates
9. Assembly Estimate

In assembly estimating, rather than bidding each of the individual components of the project, the estimator bids the components in groups known as assemblies.

The installation of the components of an assembly may be limited to a single trade or may be installed by many different trades.

Many high-end estimating computer programs, such as WinEst & Timberline, allow the user to prepare detailed estimates by taking off assemblies. This simplifies the estimating process & increases the productivity of the estimator.

Assembly estimating is also useful for conceptual & preliminary estimates. By using broad assemblies, an estimate can be prepared quickly for an entire building.

For example, an estimate for a warehouse can be prepared by using assembles for the spot footings, the continuous footings, the foundation wall, the floor slab (slab, reinforcement), the exterior wall, personnel doors, overhead doors, joist & deck roof structure (including supports), roof insulation, roofing, wall cap, skylights, bathrooms, fire sprinklers, heating, lighting, & power distribution.

Types of Estimates
10. Square-Foot Estimate

Square-foot estimates are prepared by multiplying the square footage of a building by a cost per square foot & then adjusting the price to compensate for differences in the building heights, length of the building perimeter, & other building components. In some cases, a unit other than square footage is used to measure the size of the building.

For example, the size of a parking garage may be measured by the number of parking stalls in the garage.

The information required to produce a square-foot estimate is much less than is needed to prepare a detailed estimate.

For example, a preliminary set of design drawings (a single-line floor plan & key elevations) would have the dimensions that are necessary to prepare a square-foot estimate.

Square-foot estimates are helpful to check whether the project, as designed, is within the owner’s budget. Like an assembly estimate that uses broad assemblies, care must be exercised while preparing a square-foot estimate to ensure that the projects used to determine the cost per square foot are similar to the proposed project.

Types of Estimates
11. Parametric Estimates

Parametric estimates use equations that express the statistical relationship between building parameters & the cost of the building.

The building parameters used in the equation may wp-wp-includess the gross square footage, number of floors, length of perimeter, percentage of the building that is common space, & so forth.

For an equation to be usable, the parameters used in the equation must be parameters that can be determined early in the design process; otherwise the equation is useless.

Parametric estimates are similar to square-foot estimates; however, the equations used in parametric estimates are more complex & may use log functions, ratios of parameters, & multiplication of parameters.

Parametric estimating is useful for preparing conceptual estimates based on assumptions of key building parameters or estimates based upon early designs. As with square-foot estimates & assembly estimates that use broad assemblies, care must be taken to ensure that the proposed project is similar to the projects from which the equation has been derived.

Types of Estimates
12. Model Estimating

Model estimating uses computer models to prepare an estimate based on a number of questions answered by the estimator. Model estimating is similar to assembly estimating, but it requires less input from the estimator. For example, an estimate may be prepared for a warehouse by answering the following questions:

What is the length of the building? 

How many bays are along the length of the building?

What is the width of the building?

How many bays are along the width of the building?

What is the wall height above the grade?

What is the depth (from the grade) to the top of the footing?

What is the floor thickness?

Do you want wire mesh in the slab?

How many personnel doors do you want?

How many & what size of overhead doors do you want?

How many & what size of skylights do you want?

Do you want fire sprinklers?

Types of Estimates
12. Model Estimating

On the basis of the answers to these questions, the model prepares a preliminary estimate for the project.

Logic is built into the model, such that the model selects the necessary components for the estimate based upon the answers to the questions. For example, the size of the spot footings in the center of the building that support the roof & their costs are selected based on the area of the roof the footings support, which is equal to the width of a bay multiplied by the length of a bay.

Estimating models may be complex & may prepare a detailed estimate for the entire project, or the models may be simple & prepare a preliminary estimate for part of a project.

As with square-foot estimates, assembly estimates that use broad assemblies, & parametric estimates, care must be taken to make sure that the proposed project is similar to the projects from which the model was developed.

Types of Estimates
13. Project Comparison Estimates

Project comparison estimates are prepared by comparing the cost of a proposed project to a completed project. When preparing an estimate using this method, the estimator starts with the costs of a comparable project & then makes adjustments for differences in the project.

For example, an estimate for the buildings in an apartment project may be prepared from a project built using the same plans during the previous year in a nearby city. In this example, the prices from the completed project need to be adjusted for inflation, changes in the availability & cost of labor, changes in the plans made to meet city codes, & so forth.

In most cases, the site should be estimated using another method because of the many differences in site conditions.

As with other estimating methods that do not prepare a detailed list of materials, care must be taken to ensure that the proposed project is similar to the completed project.

Estimating Opportunities

For anyone who is not aware of the many opportunities in the estimating field, this section will review some of the areas in which knowledge of estimating is necessary.

Generally, knowledge of the procedures for estimating is required by almost everyone involved in or associated with the field of construction. From the estimator, who may be involved solely with the estimating of quantities of materials & the pricing of the project, to the carpenter, who must order the material required to build the framing for a home, this knowledge is needed to do the best job possible at the most competitive cost. Others involved wp-wp-includess the project designer, drafters, engineers, contractors, subcontractors, material suppliers, & material representatives.

In the following sections, a few of the estimating opportunities are described.

Estimating Opportunities

Architectural Offices.

The architectural office will require estimates at three design stages: preliminary (rough square foot or project comparison costs), cost evaluation during drawing preparation (usually more accurate square foot or assembly costs), & a final estimate (usually based on material & installation costs, to be as accurate as possible).

For projects built using the design-build or construction manager deliver systems, the preliminary estimate is often used during negotiation with the general contactor.

Once the general contactor is hired, the general contractor’s estimator will prepare the remaining estimates. In large offices, the estimating may be done by an estimator hired primarily to do all the required estimating. In many offices, the estimating may be done by the chief drafter, head or lead architect, or perhaps someone else in the office who has developed the required estimating skills. There are also estimating services or consultants who perform estimates on a for-fee basis.

Estimating Opportunities

Engineering Offices.

The engineering offices involved in the design of building construction projects wp-wp-includess civil, structural, mechanical (plumbing, heating, air-conditioning), electrical, & soil analysis.

All of these engineering design phases require preliminary estimates, estimates while the drawings are being prepared, & final estimates as the drawings are completed. They are prepared in the same way estimates are prepared by the architects.

Estimating Opportunities

General Contractors.

For design-bid-build projects, the general contractor makes detailed estimates that are used to determine what the company will charge to do the required work. The estimator will have to take off the quantities (amounts) of each material; determine the cost to furnish (buy & get to the site) & install each material in the project; assemble the bids (prices) of subcontractors; as well as determine all of the costs of insurance, permits, office staff, & the like.

In smaller companies, one person may do the estimating, whereas in larger companies several people may work to negotiate a final price with an owner or to provide a competitive bid. On projects built using the design-build or construction manager deliver systems, the contractor’s scope of work involves providing assistance to the owners, beginning with the planning stage, & continuing through the actual construction of the project. In this type of business, the estimators will also provide preliminary estimates & then update them periodically until a final price is set.

Estimating Opportunities

Estimating with Quantities Provided.

Estimating for projects with quantity surveys involves reviewing the specifications for the contract & material requirements, reviewing the drawings for the type of construction used, & assembling the materials used. The estimator will spend part of the time getting prices from subcontractors & material suppliers & the rest of the time deciding on how the work may be most economically accomplished.

Estimating Opportunities


Subcontractors may be individuals, companies, or corporations hired by the general contractor to do a particular portion of the work on the project. Subcontractors are available for all the different types of work required to build any project & wp-wp-includess excavation, concrete, masonry (block, brick, stone), interior partitions, drywall, acoustical ceilings, painting, steel & precast concrete, erection, windows, metal & glass curtain walls, roofing, flooring (resilient, ceramic & quarry tile, carpeting, wood, terrazzo), & interior wall finishes (wallpaper, wood paneling, & sprayed-on finishes). The list continues to wp-wp-includess all materials, equipment, & finishes required.

The use of subcontractors to perform all of the work on the project is becoming an acceptable model in building construction. The advantage of this model is that the general contractor can distribute the risk associated with the project to a number of different entities. In addition, the subcontractors & craft personnel perform the same type of work on a repetitive basis & are therefore quasi experts in their niche.

However, the general contractor relinquishes a substantial amount of control over the project when this method is employed. The more that the contractor subcontracts out, the more the field operation becomes involved in coordination rather than direct supervision of craft personnel.

Estimating Opportunities


The subcontractor carefully checks the drawings & project manual & submits a price to the construction companies that will be bidding on the project. The price given may be a unit or lump sum price. If a subcontractor’s bid is presented  as what he or she would charge per unit, then it is a unit price (such as per square foot, per block, per thousand brick, per cubic yard of concrete) bid. For example, the bid might be $5.25 per linear foot (lf) of concrete curbing.

Even with unit price bids, the subcontractors need to perform a quantity takeoff in order to have an idea of what is involved in the project, at what stages they will be needed, how long it will take to complete their work, & how many workers & how much equipment will be required. The subcontractor needs the completed estimate to determine what is a reasonable amount for overhead & profit.

Estimating Opportunities


Typically, as the quantity of work increases, the associated unit cost of jobsite overhead decreases. For example, the cost of mobilization for a 100 lf of curb is $1,000 or $10 per lf; if the quantity had been 1,000 lf, it would have been $1 per lf. The subcontractor would not know how much to add to the direct field cost unit price for overhead unless a quantity takeoff had been performed. If the subcontractor submits a lump-sum bid, then he or she is proposing to install, or furnish & install, a portion of work:

For example, the bid might state, “agrees to furnish & install all Type I concrete curbing for a sum of $12,785.00.”

Each subcontractor will need someone (or several people) to check specifications, review the drawings, determine the quantities required, & put the proposal together. It may be a full-time estimating position or part of the duties assumed, perhaps in addition to purchasing materials, helping  to schedule projects, working on required shop drawings, or marketing.

Estimating Opportunities

Material Suppliers.

Suppliers submit price quotes to the contractors (& subcontractors) to supply the materials required for the construction of the project. Virtually every material used in the project will be estimated, & multiple price quotes will be sought. Estimators will have to check the specifications & drawings to be certain that the materials offered will meet all of the requirements of the contract & required delivery dates.

Estimating Opportunities

Manufacturers’ Representatives.

Manufacturers’ representatives represent certain materials, product suppliers, or manufacturers. They spend part of their time visiting contractors, architects, engineers, subcontractors, owners, & developers to be certain that they are aware of the availability of the material, its uses, & approximate costs. In a sense they are salespeople, but their services & the expertise they develop in their product lines make good manufacturers’ representatives welcome not as salespersons, but as needed sources of information concerning the materials & products they represent. Representatives may work for one company, or they may represent two or more.

Manufacturers’ representatives will carefully check the specifications & drawings to be certain that their materials meet all requirements. If some aspect of the specifications or drawings tends to exclude their product, or if they feel there may be a mistake or misunderstanding in these documents, they may call the architects/engineers & discuss it with them. In addition, many times they will be involved in working up various cost analyses of what the materials’ or products’ installed cost will be & in devising new uses for the materials, alternate construction techniques, & even the development of new products.

Estimating Opportunities

Project Management.

Project management companies specialize in providing professional assistance in planning the construction of a project & keeping accurate & updated information about the financial status of the project. Owners who are coordinating large projects often hire such companies. Among the various types of owners are private individuals, corporations, municipal government agencies (such as wp-content/uploads works & engineering departments), & various wp-content/uploads utility companies. Both the firms involved in project management, as well as someone on the staff of the owner being represented, must be knowledgeable in estimating & scheduling projects.


When a government agency is involved in any phase of construction, personnel with experience in construction & estimating are required. Included are local, state or province, & nationwide agencies, including those involved in highways, roads, sewage treatment, schools, courthouses, nursing homes, hospitals, & single & multifamily dwellings financed or qualifying for financing by the government. Employees may be involved in preparing or assisting to prepare preliminary & final estimates; reviewing estimates from architects, engineers, & contractors; the design & drawing of the project; & preparation of the specifications.

Estimating Opportunities

Professional Quantity Surveyors.

Professional Quantity surveyors are for-hire firms or individuals who make unit quantity takeoffs of materials required to build a project. They are available to provide this service to all who need it, including governmental agencies.

Freelance Estimators.

Freelance estimators will do a material takeoff of a portion or entire project for whoever may want a job done. This estimator may work for the owner, architect, engineer, contractor, subcontractor, material supplier, or manufacturer. In some areas, the estimator will do a material takeoff of a project being competitively bid & then sell the quantity list to one or more contractors who intend to submit a bid on the project. Many times a talented individual has a combined drafting & estimating business. Part of the drafting business may wp-wp-includess preparing shop drawings (drawings that show sizes of materials & installation details) for subcontractors, material suppliers, & manufacturers’ representatives.

Estimating Opportunities

Residential Construction.

Estimators are also required for the contractors, material suppliers, manufacturers’ representatives, & most of the subcontractors involved in residential construction. From the designer who plans the house & the drafter who draws the plans & elevations to the carpenters who put up the rough framing & the roofers who install the roofing material, knowledge of estimating is necessary.

The designer & drafter should plan & draw the house plans using standard material sizes when possible (or being aware of it when they are not using standard sizes). In addition, they will need to give preliminary & final estimates to the owner. Workers need to have a basic knowledge of estimating so they can be certain that adequate material has been ordered & will be delivered by the time it is needed.

Estimating Opportunities

Computer Software.

The use of computers throughout the world of construction offers many different types of opportunities to the estimator. Job opportunities in all the areas mentioned earlier will be centered on the ability to understand, use, & manipulate computer software. The software available today integrates the construction drawings, estimating, bidding, purchasing, & management controls of the project. Some construction consultants specialize in building databases for computerized estimating systems & training estimators in the use these systems.

The Estimator

Most estimators begin their career doing quantity takeoff; as they develop experience & judgment, they develop into estimators. A list of the abilities most important to the success of an estimator follows, but it should be more than simply read through. Any weaknesses affect the estimator’s ability to produce complete & accurate estimates. If individuals lack any of these abilities, they must (1) be able to admit it & (2) begin to acquire the abilities they lack. Those with construction experience, who are subsequently trained as estimators, are often most successful in this field.

The Estimator

To be able to do quantity takeoffs, the estimator must

  1. Be able to read & quantify plans.
  2. Have knowledge of mathematics & a keen understanding of geometry. Most measurements & computations are made in linear feet, square feet, square yards, cubic feet, & cubic yards. The quantities are usually multiplied by a unit price to calculate material costs.
  3. Have the patience & ability to do careful, thorough work.
  4. Be computer literate & use computer takeoff programs such as On-Screen Takeoff or Paydirt.

The Estimator

  1. Be able, from looking at the drawings, to visualize the project through its various phases of construction. In addition, an estimator must be able to foresee problems, such as the placement of equipment or material storage, then develop a solution & determine its estimated cost.
  2. Have enough construction experience to possess a good knowledge of job conditions, including methods of handling materials on the job, the most economical methods of construction, & labor productivity. With this experience, the estimator will be able to visualize the construction of the project & thus get the most accurate estimate on paper.
  3. Have sufficient knowledge of labor operations & productivity to thus convert them into costs on a project. The estimator must understand how much work can be accomplished under given conditions by given crafts. Experience in construction & a study of projects that have been completed are required to develop this ability.

The Estimator

  1. Be able to keep a database of information on costs of all kinds, including those of labor, material, project overhead, & equipment, as well as knowledge of the availability of all the required items.
  2. Be computer literate & know how to manipulate & build various databases & use spreadsheet programs & other estimating software.
  3. Be able to meet bid deadlines & still remain calm. Even in the rush of last-minute phone calls & the competitive feeling that seems to electrify the atmosphere just before the bids are due, estimators must “keep their cool.”
  4. Have good writing & presentation skills. With more bids being awarded to the best bid, rather than the lowest bid, being able to communicate what your company has to offer, what is wp-wp-includessd in the bid, & selling your services is very important. It is also important to communicate to the project superintendent what is wp-wp-includessd in the bid, how the estimator planned to construct the project, & any potential pitfalls.

The Estimator

People cannot be taught experience & judgment, but they can be taught an acceptable method of preparing an estimate, items to wp-wp-includess in the estimate, calculations required, & how to make them. They can also be warned against possible errors & alerted to certain problems & dangers, but the practical experience & use of good judgment required cannot be taught & must be obtained over time.

How closely the estimated cost will agree with the actual cost depends, to a large extent, on the estimators’ skill & judgment. Their skill enables them to use accurate estimating methods, while their judgment enables them to visualize the construction of the project throughout the stages of construction.

The Estimator


If the contractor is aware of potential discrepancies between the estimated quantities & those that will be required, the contractor may price his or her bid to take advantage of this situation. With a belief that the estimated quantities are low, the contractor may reduce his or her unit price to be the low bidder. If the assumption is true, the contractor has the potential to make the same profit by distributing the project overhead over a greater number of units.

Books on Estimating & Costing in Construction

Few Definitions

  1. Form work :
    All arrangement done to support the green concrete till it attains the strength is known as form work or temporary work. Form work determines the geometry, shape, size and finish of the form work.
  2. Centering :
    Part of the form work which supports the horizontal surface is called centering for example slab bottom , beam bottom etc.
  3. Shuttering :

  Part of the form work which supports the Vertical surface is called Shuttering for example column sides, beam sides, slab side ,wall side etc.

  1. Staging :

  That portion which support centering & shuttering is called Staging. This can be :
Wooden Ballies, Pipes/Props/Jacks, H frames, Space frames using Coupler / Cup-Lock system

  1. Scaffolding :

  That arrangement which is meant to be a supporting platform for people ( labor, supervisor, mason ,fitter, painter, carpenter etc. ) is known as scaffolding.

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