L1B Estimating Methods

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.


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.


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


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.


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.


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).


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


8/11

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


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


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


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)

Documents

L1B Estimating Methods