BT M2

Estimates

Approximation, projection or prediction of a

quantity of work; a statement of the approximate or

projected cost of work to be done

Quantity Survey

A term describing the detailed calculation of all

components necessary to construct a building

generated by quantity of materials, labor and other

parameters

Detailed Estimate of Construction Cost

A forecast of construction cost prepared on the

basis of a detailed analysis of materials and labor

for all items of work, as contrasted with an estimate

based on current area, volume, or similar unit costs.

Bill of Materials

A term used to describe the materials, sub-

components needed to manufacture a finished

product.

User-Unit Method

This estimating method involves the

determination of user or occupants to quantify

space and to establish cost, e.g. number of

students, patient beds, inmates, etc.

Area Method

Involves costing and quantification using area and multiplier or factor. Estimate of project cost by multiplying area by cost per unit area (usually square meter) based

on prevailing rate.

Volume Method

This method involves a three-dimensional aspect

of the project. Such method is an extension of the

area method but involves the height of the

building project as height affects cost of the

project.

Parametric Method

involves the identification of several major factors in estimating such as architectural, structural, electrical, plumbing/ sanitary, mechanical, etc.

Modular Cost Method

Estimates applies to repetitive work composition such as apartment, housing units or hospital room units where cost can be calculated based on the cost per unit

Detailed Estimate by Quantity Take-off (Quantity Survey) Method

This method is considered as the most precise of

the different types of estimating method.

Materials are quantified base on specifications –

1type, composition, application, commercial sizes

and other parameters.

Combination Method

This method may be used although not that

accurate if the project and the scope of work is

incomplete or some areas of the project are not

clearly defined, hence, a combination of different

methods becomes practicable

Excavation

Earth volume (m3) = excavation volume x 1.25

Filling/Backfilling

Total earth volume (filling/backfilling) = volume of

earthfill (measured volume) x 1.25

350 psi

Compressive strength

of CHB (non-load bearing block).

50 pcs - 6“ CHB

sing a ratio of

1:5, 1 bag of cement per 5 bags of sand, a bag of cement can produce

750 psi

Compressive

strength for load-bearing block

12.5 pcs per sq.

meter

No. of blocks per square meter

2% - 4% Steel percentage

RC Column

0.2m x 0.4m

Face area per block

0.20 x 0.40 x 0.1, 0.125, 0.15

Stretcher block sizes

12 bags

AA 1:1 ½: 3

9 bags

A 1: 2: 4

7.5 bags

B 1: 2 ½: 5

6 bags

C 1: 3: 6

5 bags

D 1: 3 ½: 7

0.5

Sand Estimate

1.0

Gravel Estimate

40kgs

bag or Portland Cement weighs

1600

cubic meter of sand dry weighs

1442

cubic meter of sand loose weighs

1520

cubic meter if gravel

0.19 Cement 0.014 Sand

4” x 8” x 16” CHB

0.25 Cement 0.019 Sand

5” x 8” x 16” CHB

0.29 Cement 0.024 Sand

6” x 8” x 16” CHB

0.34 Cement 0.028 Sand

8” x 8” x 16” CHB

18

Class A 1:2

12

Class B 1:3

9

Class C 1:4

7.5

Class D 1:5

0.0015

Plaster volume per block 1 face

0.003

Plaster volume per block 2 faces