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8/10/2019 L1B Estimating Methods
1/11
DR SHAIFUL AMRI
FKA UTM SKUDAI
Building Constructions
Building construction estimating is thedetermination of probable construction costs ofany given project.
Many items influence and contribute to the costof a project:
each item must be analyzed, quantified, and priced.Because the estimate is prepared before theactual construction,much study and thoughtmust be put into the construction documents.
8/10/2019 L1B Estimating Methods
2/11
DR SHAIFUL AMRI
FKA UTM SKUDAI
The purpose of pre-tender price estimating is toprovide an indication of the probable costs ofconstruction at a very early stage in the life of aconstruction project.
It is one of the most important factorsinfluencing the clients decision to build.
Definition of Estimating
a prediction of probable cost
prediction based on consideration andexperience.
forecast of probable future cost of construction
activity based on reliable information.
a process to determine how much the cost ofthe building should be and to help the client toallocate the financial budget before any designis prepared.
8/10/2019 L1B Estimating Methods
3/11
DR SHAIFUL AMRI
FKA UTM SKUDAI
QS starts with preparing conceptual costestimate (anggaran kos awal), which is normallylack accuracy.
Once project summary is received from client,QS will verify the allocated funds. If notsufficient, QS should advise the PM to:
Re-evaluate the design or project scope to reducecost
Ask for additional funds if necessary
Concept
Preliminary design
Detailed design
Prepare tender
Construction
Project complete
PRELIMINARY + 25%
ELEMENTAL + 15%
UNIT PRICE + 10%
DETAILED + 5%
ACTUAL COST
8/10/2019 L1B Estimating Methods
4/11
DR SHAIFUL AMRI
FKA UTM SKUDAI
1. Detailed estimates
need good take-off andusually lump-sum or unit-price
2. Unit pricefairly detailed but uncertainquantity or volume
3. Elementalbreakdown to functionalelements (need drawings & specifications)
4. Preliminaryno of beds; by area; no of
parkings, etc.
1. Detailed estimates
includes determination of the quantities andcosts of everything that is required to completethe project (includes materials, labor,equipment, insurance, bonds, and overhead, as
well as an estimate of the profit.To perform this type of estimate, the contractormust have a complete set of contractdocuments.
Each item of the project should be broken downinto its parts and estimated.
8/10/2019 L1B Estimating Methods
5/11
DR SHAIFUL AMRI
FKA UTM SKUDAI
2. Assembly estimatesrather than bidding each of the individualcomponents of the project, the estimator bidsthe components in groups known as assemblies.
useful for conceptual and preliminary estimates.
using broad assemblies, an estimate can beprepared quickly for an entire building.
a bit less accurate.
3. Square-foot estimates
prepared by multiplying the square footage of abuilding by a cost per square foot and thenadjusting the price to compensate fordifferences in the building heights, length of the
building perimeter, and other buildingcomponents.
8/10/2019 L1B Estimating Methods
6/11
DR SHAIFUL AMRI
FKA UTM SKUDAI
4. Parametric estimatesuse equations that express the statisticalrelationship between building parameters andthe cost of the building.
for an equation to be usable, the parametersused in the equation must be determined earlyin the design process; otherwise the equation isuseless.
similar to square-foot estimates; however, theequations used are more complex
5. Comparison estimates
prepared by comparing the cost of a proposedproject to a completed project.
the estimator starts with the costs of acomparable project and then makes
adjustments for differences in the project (e.g.an estimate prepared from a project built usingthe same plans during the previous year in anearby city; adjusted for inflation, availabilityand cost of labor, city codes, and so forth).
8/10/2019 L1B Estimating Methods
7/11
DR SHAIFUL AMRI
FKA UTM SKUDAI
1. KAEDAH ISIPADU (cube method)2. KAEDAH KELUASAN LANTAI (superficial
method)
3. KAEDAH PENILAIAN UNIT (unit method)
4. KAEDAH KUANTITI NILAI HAMPIR (approximatequantities)
5. KAEDAH SENARAI KUANTITI (bill of quantities)
For pitch-roof
Vol = (c + b + a/2) * L * w
If cost = RM 10/Vol
Estimated cost = [(c + b + a/2) * L * w] * 10
8/10/2019 L1B Estimating Methods
8/11
DR SHAIFUL AMRI
FKA UTM SKUDAI
For flat-roofVol = (c + b + a) * L * w
If cost = RM 10/Vol
Estimated cost = [(c + b + a) * L * w] * 10
For others
Vol = [a + 2(0.112)] * [b + 2(0.112)] * t
8/10/2019 L1B Estimating Methods
9/11
DR SHAIFUL AMRI
FKA UTM SKUDAI
For othersVol = L * w * (c +d)
Surface area measured between interiorsurface of outer wall of each level (notincluding interior wall)
Dimensions inside perimeter
wall measured over partitions
8/10/2019 L1B Estimating Methods
10/11
DR SHAIFUL AMRI
FKA UTM SKUDAI
1
Or measured between outer surface ofcolumns if there is no outer walls
Dimensions taken from
outside faces of perimeter
columns
a. Bangunan 3,339 mp X RM550/mp 1,836,450
b. Kerja M & E 459,112
c. Kerja Luar & Infrastruktur 367,290
d. Kerja Cerucuk 183,645
e. Kerja Lanskap 50,000
Sub total 2,896,497
f. Kerja Permulaan (5% X 2,896,497) 145,000
g. Perabot (10% bangunan) 183,645
Sub total 3,225,142
h. Yuran Perunding 387,017
i. Pengawasan 90,000
j. Cukai Perkhidmatan 19,350
JUMLAH 3,721,509
KATAKAN RM3.7
JUTA
8/10/2019 L1B Estimating Methods
11/11
DR SHAIFUL AMRI
FKA UTM SKUDAI
Unit methodcomparing similar facility (perbed; per parking; per student; etc.)
Approximate quantitiesConstruction costsshall be itemised according to types & works
Bill of quantitiesconsidered the most
accurate (systematic)
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