EstimationandCosting.ppt

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1. KATTUMANNARKOVIL
DEPARTMENT OF CIVIL ENGINEERING
CE8701-ESTIMATION, COSTING AND
VALUATION ENGINEERING
Prepared by
R.BALAMURUGAN
Assistant Professor
Department of Civil
Engineering

2. CE8701 ESTIMATION, COSTING AND VALUATION ENGINEERING L T P C
3 0 0 3
OBJECTIVE:
The students will acquire knowledge in estimation, tender practices, contract
procedures, and valuation and will be able to prepare estimates, call for tenders and
execute works.
UNIT I QUANTITY ESTIMATION 9
Philosophy –Purpose –Methods of estimation –Types of estimates –Approximate
estimates –Detailed estimate –Estimation of quantities for buildings, bituminous and
cement concrete roads, septic tank, soak pit, retaining walls –culverts (additional
practice in class room using computer softwares)
UNIT II RATE ANALYSIS AND COSTING 9
Standard Data –Observed Data –Schedule of rates –Market rates –Standard Data
for Man Hours and Machineries for common civil works –Rate Analysis for all
Building works, canals, and Roads–Cost Estimates (additional practice in class
room using Computer softwares) -(Analysis of rates for the item of work asked, the
data regarding labour, rates of material and rates of labour to be given in the
Examination Question Paper)

3. UNITIIISPECIFICATIONS,REPORTSANDTENDERS
9
Specifications–Detailedandgeneralspecifications–Constructions–Sources–
Typesofspecifications–Principlesforreportpreparation–reportonestimateof
residentialbuilding–Culvert–Roads–TTTAct2000–Tendernotices–types–
tenderprocedures–Draftingmodeltenders,E-tendering-Digitalsignature
certificates-Encrypting-Decrypting–Reverseauctions.
UNITIVCONTRACTS
9
Contract–Typesofcontracts–Formationofcontract–Contractconditions–
Contractforlabour,material,design,construction–Draftingofcontractdocuments
basedonIBRD/MORTHStandardbiddingdocuments–Constructioncontracts–
Contractproblems–Arbitrationandlegalrequirements.
UNITVVALUATION
9
Definitions–Varioustypesofvaluations–Valuationmethods-Necessity–
Capitalisedvalue–Depreciation–Escalation–Valuationofland–Buildings–
CalculationofStandardrent–Mortgage–Lease

4. ESTIMATION
Estimationisthescientificwayofworkingoutthe
approximatecostofanengineeringprojectbefore
executionofthework.
Itmaydifferfromthecalculationoftheexactcost
aftercompletionoftheproject.
EstimationrequiresathoroughKnowledgeofthe
constructionprocedures,costofmaterials&labour
inadditiontotheskill,experience,foresightand
goodjudgment.
Department of Civil
Engineering

5. ESTIMATE
Anestimateofthecostofaconstructionjobisthe
probablecostofthatjobascomputedfromplans
andspecifications.
Foragoodestimatetheactualcostoftheproposed
workaftercompletionshouldnotdifferbymore
than5to10%fromitsapproximatecostestimate.
Department of Civil
Engineering

6. UNITS OF MEASUREMENTS
Theunitsofmeasurementsaremainlycategorized
fortheirnature,shapeandsizeandformaking
paymentstothecontractor.
a)Singleunitsworklikedoors,windowsetc,isexpressedinnumbers.
b)Worksconsistslinearmeasurementsinvolvelengthlikecornice,
fencing,handrailetc.,areexpressedinrunningmeters(RM)
c)Worksconsistsarealsurfacemeasurementslikeplastering,white
washing,partitionsofspecifiedthicknessetc.,areexpressedin
squaremeters.
d)Worksconsistscubicalcontentswhichinvolvevolumelikeearth
work,cementconcrete,Masonryetc.,areexpressedinCubicmeters.
Department of Civil
Engineering

7. NEED OF ESTIMATION & COSTING
1.Ithelptoworkouttheapproximatecostoftheprojectinorder
todecideitsfeasibilitywithrespecttothecostandtoensure
thefinancialresources.
2.Requirementsofcontrolledmaterials,suchascementandsteel
canbeestimated.
3.Itisusedforframingthetendersfortheworksandtocheck
contractor’sworkduringandaftertheitsexecutionforthe
purposeofmakingpaymentstothecontractor.
4.Fromquantitiesofdifferentitemsofworkcalculatedindetailed
estimation,resourcesareallocatedtodifferentactivitiesofthe
projectandultimatelytheirdurationsandwholeplanningand
schedulingoftheprojectiscarriedout.
Department of Civil
Engineering

8. DATA REQUIRED TO PREPARE AN ESTIMATE
1)DRAWINGS
Ifthedrawingsarenotclearandwithoutcomplete
dimensionsthepreparationofestimationbecomevery
difficult.So,itisveryessentialbeforepreparinganestimate.
2)SPECIFICATIONS
a)GeneralSpecifications:
Thisgivesthenature,qualityofworkandmaterialsingeneral
termstobeusedinvariouspartsofwok.Ithelpstoformageneral
ideaofbuilding.
b)DetailedSpecifications:
Thisgivesthedetaileddescriptionofthevariousitemsofwork
layingdowntheQuantitiesandqualitiesofmaterials,their
proportions,themethodofpreparationworkmanshipand
executionofwork.
Department of Civil
Engineering

9. 3)RATES
Forpreparingtheestimatetheunitratesofeachitemofwork
arerequired.
1.Forarrivingattheunitratesofeachitem.
2.Theratesofvariousmaterialstobeusedintheconstruction.
3.Thecostoftransportmaterials.
4.Thewagesoflabor,skilledorunskilledofmasons,carpenters,
Amador,etc.,
LUMPSUM:
Whilepreparinganestimate,itisnotpossibletoworkoutin
detailincaseofpettyitems.Itemsotherthancivilengineering
suchitemsarecalledlumpsumitemsorsimplyL.S.Items.
Department of Civil
Engineering

10. Factors to be considered for estimation
1.Eachtypeofworkrequiresadifferentmethodofconstruction.
Constructionmaybeofanordinaryhouseorofficeanditmay
alsobeofaDam,Tunnel,Multistorybuilding,Airport,Bridge,
oraRoad,alreadyinoperation.Eachoftheseworksrequires
totallydifferentconstructiontechniques,typeofmachinery,
andformwork.
2.Qualityoflabourandlabouroutputvariesindifferentlocalities.
3.Weatherconditionsgreatlyaffecttheoutputand,hence,the
overallcost.
Department of Civil
Engineering

11. Factors to be considered for estimation (-ctd-)
4.Groundconditionsvaryandchangethemethodof
construction.Forexample,excavationmaybedry,wet,hard,
soft,shallowordeeprequiringdifferentefforts.
5.Thesourceofavailabilityofasufficientsupplyofmaterialsof
goodquality.
6.Theavailabilityofconstructionmachineryalsoaffectsthe
methodofconstruction.
7.Accesstothesitemustbereasonable.Iftheaccessispoor,
temporaryroadsmaybeconstructed.
Department of Civil
Engineering

12. TYPES OF ESTIMATES
There are two main types of estimates:-
Rough (or) approximate estimate.
Detailed estimate.
Department of Civil
Engineering

13. Rough (or) approximate estimate
•Preliminaryorapproximateestimateisrequiredfor
studiesofvariousaspectsofworkofprojectandforits
administrativeapproval.
•Itcandecide,incaseofcommercialprojects,whether
thenetincomeearnedjustifiestheamountinvestedor
not.Theapproximateestimateispreparedfromthe
practicalknowledgeandcostofsimilarworks.
•The following are the methods used for preparation of
approximate estimates.
1)Plinth area method
2)Cubical contents methods
3)Unit base method.
Department of Civil
Engineering

14. 1)Plinthareamethod
costofconstruction=Plinthareaxplintharearate.
2)CubicalContentsMethod
Itismoreaccuratethattheothertwomethodsviz.,plinthareamethod
andunitbasemethod.
costofconstruction=TotalcubicalcontentsxLocalCubicRate.
3)UnitBaseMethod
.Forpublicbuildings,cost.Perperson(costpercapita)is used.
Forexample,
Studentshostel-costperstudent
Hospital-Costperbed
Hotel-CostperGuest
Department of Civil
Engineering

15. EXAMPLE 1
•PrepareaRough-costEstimateofaresidentialbuilding
projectwithatotalplinthareaofallbuildingof1500sq.m.
giventhat:
•PlinthAreaRate=Rs:950.00/sq.ft.
•Extraforspecialarchitecturaltreatment=1.5%ofthe
buidingcost.
•Extraforwatersupplyandsanitaryinstallations=5%of
thebuildingcost.
•Extraforinternalinstallations=14%ofthebuidingcost
•ExtraforElectric&Suigasservices=16%ofbuidingcost
•Contigencies3%overall
•Supervisioncharges=8%overall
•Designcharges=2%overallDepartment of Civil
Engineering

16. EXAMPLE 2
•PrepareaRough-costEstimatebasedonunitcostsofperunitplinth
areabasisofafourstoreyedofficebuildinghavingacarpetareaof2000
sq.m.forobtainingtheadministrativeapprovaloftheGovernment.It
maybeassumedthat30%ofthebuiltupareawillbetakenbythe
corridors,verandas,lavatories,staircase,etc.and10%ofbuiltuparea
willbeoccupiedbywalls.Thefollowingdataisgiven:
•PlinthAreaRate=Rs:1100.00/sq.ft.
•Extraforspecialarchitecturaltreatment=0.5%ofthebuidingcost.
•Extraforwatersupplyandsanitaryinstallations=6%ofthebuilding
cost.
Department of Civil
Engineering

17. Example 2 (ctd)
•Extra for internal installations = 14 % of the buiding cost
•Extra for electric services = 12.5 % of buiding cost
•Extra for sui gas services = 6 % of buiding cost
•Extra due to deep foundations at site = 1.0 % of buiding cost
•Contigencies = 2.5 % overall
•Supervision charges = 8 % overall
•Design charges = 2.5 % overall
Department of Civil
Engineering

18. DETAILED ESTIMATE
•Detailedestimatesarepreparedbycarefullyandseparately
calculatingthecostsofvariousitemoftheworkthatconstitute
thewholeprojectfromthedetailedworkingdrawingsafterthe
designhasbeenfinalized.
•Themistakes,ifany,intheroughcostestimateareeliminatedin
thedetailedestimate.
•Detailedestimatesaresubmittedtothecompetentauthorities
forobtainingtechnicalsanction.
Department of Civil
Engineering

19. DETAILED ESTIMATE
•Thewholeprojectissub-dividedintodifferentitemsofworkor
activities.Thequantityforeachitemisthencalculated
separatelyfromthedrawingsasaccuratelyaspossible.The
procedureisknownas"takingoutofquantities".
•Thequantitiesforeachitemmaybeestimatedandshownin
thepatternwhichiscalled"Billofquantities."
•Theunit,inwhicheachitemofthewokistobecalculated,
shouldbeaccordingtotheprevailingpracticeasfollowedin
variousdepartmentsofthecountry.
Department of Civil
Engineering

20. BILL OF QUANTITIES
Sr. No
Description
of item
No Measurements Quantity Total
Quantity
Remarks
Length Breadth Height
Department of Civil
Engineering

21. PRICED BILL OF QUANTITIES
Sr. No. Description of Item Unit Quantity Rate Cost Remarks
Department of Civil
Engineering

22. DETAILED ESTIMATE
•Eachitemoftheworkisthenmultipliedbyitsestimatedcurrent
ratecalculatedbyafixedproceduretofindoutcostoftheitem.
•Attheend,atotalofallitemsoftheworkaremadetogetthetotal
estimatedcost.
•TheratesareusuallyasperScheduleofRatesforthelocalityplusa
premiumtoallowforriseinlaborandmaterialratesoverand
abovethescheduleofrates.
•Apercentage,usually5%isalsoprovidedonthetotalestimated
costfortheworktoallowforthepossiblecontingenciesdueto
unforeseenitemsorexpenditureorothercauses,besides2%
establishmentcharges.
Department of Civil
Engineering

23. DETAILED ESTIMATE
Besidesdrawingsanddetailsofmeasurementsandcalculationofquantities(Bill
ofQuantities),thefollowingdocumentsarealsousuallysubmittedwiththe
detailedestimateforobtainingTechnicalSanction:
1.AreportexplainingHistory,necessity,scopeandmain
featuresoftheproject,itsdesign,andestimate,etc.
2.Specificationslyingdownthenatureandclassofwork
andmaterialtobeusedinvariouspartsofthework.
3.Theabstractofcost(pricedBillofQuantities)showing
thetotalquantitiesundereachsub-head,rateperunit
ofmeasurement,andcost.
4.Calculationsheetsshowingcalculationsforimportant
partsofthestructure.Infact,inestimatingtheartand
skillliesonlyinthecomputationofdetailswithoutany
omissions,ofallpartsofthebuildingorwork.
Department of Civil
Engineering

24. METHODS OF DETAILED ESTIMATE
•Thedimensions,length,breadthandheightordeptharetobe
takenoutfromtheworkingdrawings(plan,elevationandsection).
•Junctionsofwalls,cornersandthemeetingpointsofwallsrequire
specialattention.
•Forsymmetricalfootings,whichistheusualcase,earthworkin
excavationinfoundations,foundationconcrete,brickworkin
foundationandplinth,andbrickworkinsuperstructuremaybe
estimatedbyeitherofthetwomethods:
(1)LONGWALL&SHORTWALLMETHOD
(2)CENTERLINEMETHOD
Department of Civil
Engineering

25. LONG WALL & SHORT WALL METHOD (or)
SEPARATE WALL METHOD
•Thewallsrunninginonedirectionaretermedas"long
walls”andthewallsrunninginthetransverse
direction,as"Shortwalls.
•Lengthsoflongwallsaremeasuredorfound"Out-to
out"andthoseofshortwallsas"In-to-in".
•Differentquantitiesarecalculatedbymultiplyingthe
lengthbythebreadthandtheheightofthewall.
Department of Civil
Engineering

26. LONG WALL & SHORT WALL METHOD
•Longwalllengthout-to-out
=Centertocenterlength+halfbreadthononeSide+half
breadthonotherside.
=Centertocenterlength+onebreadth
•Shortwalllengthin-to-in
=CentertoCenterlength-onebreadth.
Department of Civil
Engineering

27. CENTER LINE METHOD
•Inthismethod,totallengthofcenterlinesofwalls,longand
short,hastobefoundout.
•Inthismethod,thelengthwillremainthesamefor
excavationinfoundations,forconcreteinfoundations,forall
footings,andforsuperstructure(withslightdifferencewhen
therearecrosswallsornumberofjunctions).
•Thismethodisquickerbutrequiresspecialattentionand
considerationsatthejunctions,meetingpointsofpartition
orcrosswalls.
Department of Civil
Engineering

28. CENTER LINE METHOD
Forrectangular,circularpolygonal(hexagonal,octagonal
etc.,)buildingshavingnointerorcrosswalls,thismethodis
quitesimple.
Forbuildingshavingcrossorpartitionwalls,forevery
junction,halfbreadthoftherespectiveitemorfootingisto
bedeductedfromthetotalcenterlength.
Thusinthecaseofabuildingwithonepartitionwallor
crosswallhavingtwojunctions,deductonebreadthofthe
respectiveitemofworkfromthetotalcenterlength.
Department of Civil
Engineering

29. Problem-1
Estimateindetailthequantitiesoffollowing
itemsofworkforagivenplanandsectionas
showninFig.1usingCentrelinemethodand
Longwall&shortwallmethod.
Concreteinfoundation
Brickworkin1
st
stepinfoundation
Firstclassbrickworkinsuperstructures
Department of Civil
Engineering

30. Department of Civil
Engineering

31. Estimation of Quantity of Concrete in
Foundation

32. Center Line method:
Total Length of Center Line = 5.3+5.3+4.3+4.3 = 19.2 m
width of foundation = 0.9 m Total quantity of concrete in foundation =19.2x0.9x0.3 cu.m
Department of Civil
Engineering

33. Long Wall & Short Wall method:
Length of Long wall = 5.3+0.9 = 6.2 m Length of Short wall = 4.3-0.9 = 3.4 m
Quantity of concrete in foundation = 2 x (6.2+3.4) x 0.9 x 0.3 cu.m
Department of Civil
Engineering

34. Estimation of Quantity of Brickwork in
1
st
step Foundation
Department of Civil
Engineering

35. Center Line method:
Total Length of Center Line = 5.3+5.3+4.3+4.3 = 19.2 m
width of foundation = 0.6 m
Total quantity of brickwork in 1
st
step foundation = 19.2 x 0.9 x 0.3 cu.m
Department of Civil
Engineering

36. Long Wall & Short Wall method:
Length of Long wall = 5.3+0.6 = 5.9 m Length of Short wall = 4.3-0.6 = 3.7 m
Quantity of brickwork in 1
st
step foundation = 2 x (5.9+3.7) x 0.6 x 0.3 cu.m
Department of Civil
Engineering

37. Estimation of Quantity of
Brickwork in super structure
Department of Civil
Engineering

38. Center Line method:
Total Length of Center Line = 5.3+5.3+4.3+4.3 = 19.2 m
width of wall = 0.3 m Total quantity of brickwork in wall = 19.2 x 3.5 x 0.3 cu.m
Department of Civil
Engineering

39. Long Wall & Short Wall method:
Length of Long wall = 5.3+0.3 = 5.6 m Length of Short wall = 4.3-0.3 = 4.0 m
Quantity of brickwork in wall = 2 x (5.6+4.0) x 0.3 x 3.5 cu.m
Department of Civil
Engineering

40. Problem-2
Estimateindetailthequantitiesoffollowingitems
ofworkforagivenplanandsectionasshownin
Fig.2usingCentrelinemethodandLongwall&
shortwallmethod.
Concreteinfoundation
Brickworkin1
st
stepinfoundation
Firstclassbrickworkinsuperstructures
Department of Civil
Engineering

41. Department of Civil
Engineering

42. Estimation of Quantity of Concrete in
Foundation

43. CenterLinemethod:
TotalLengthofCenterLine=(4x5.3)+(3x4.3)=34.1–0.9=33.2m
widthoffoundation=0.9m
Totalquantityofconcreteinfoundation=33.2x0.9x0.3cu.m
Department of Civil
Engineering

44. Long Wall & Short Wall method:
Length of Long wall = 5.3+5.3+0.9 = 11.5 m Length of Short wall = 4.3-0.9 = 3.4 m
Quantity of concrete in foundation= [ (2x11.5) + (3X3.4) ] x 0.9 x 0.3 cu.m
Department of Civil
Engineering

45. References:
•Dutta,B.N.,“EstimatingandCostingin
CivilEngineering”,UBSPublishers&
DistributorsPvt.Ltd.,NewDelhi,2003.
•https://www.wikipedia.org/
•https://nptel.ac.in/course.php
•https://www.vidyarthiplus.com/studymat
erials.php

46. THANK YOU
Department of Civil
Engineering