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Abdul Jalil
2010-2011
Approximate Estimation
Approximate estimation (fast estimation):
The approximate estimation is prepared before laying the final designs & specification and general
specification of the project.
The purpose of approximate estimation is:
1. Determine the cost of the structure quickly.
2. Make a comparison between several alternatives.
3. Checking the final cost of the structure which determined by detailed estimation.
Method of used for approximate estimation:
1. Floor – Area method. (Price of one square meter of building).
Use to determine the cost of the following building:
(Offices, Schools, Houses, Apartments, Hospitals …..Etc.) .
It is the best method for determining the cost of the new building , depending on the results getting
from old buildings ( buildingsbuiltbefore ).
For the multi-story building there are two assumptions :
A. The cost of all floors with in basement and roof are in equal costs for one meter square.
B. The cost of the basement is (60%) and roof is (40%) of the other floors.
2. Cubic method , (volumetric method )
This method is more accurate than the floor-area method.
For multi-story buildings apply the following assumptions:
A. All floors are in equal costs for one cubic meter.
B. The cost of the basement is (60%) of the cost of other floors.
The volume of the floor is calculated as:
𝑉𝑜𝑙𝑢𝑚𝑒 = 𝐴𝑟𝑒𝑎 × 𝐻𝑒𝑖𝑔ℎ𝑡 𝑜𝑓 𝑜𝑛𝑒 𝑓𝑙𝑜𝑜𝑟
The height of the floors is determined as follows:
a. Ground floor : From the top of the footing to the mid height of the parapet.
b. Top floor
: From the top of the ground roof to the mid height of the parapet.
c. Middle floors : From floor to floor.
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Abdul Jalil
2010-2011
Middle floor
Top floor
Ground floor
Example:
Building of dimensions ( 20m * 35m ) , have been executed and composed of ( basement , ground floor ,
first floor , second floor , & roof ) .
The total cost of the building was (1,100,000,000 ID).
Determine the rate of one meter square of the building depending on the following assumptions:
A. The (three floors, basement & roof) have equal cost per one meter square.
B. The cost of the basement is 60% of the cost of the other floors & the cost of the roof is 40% of the
cost of the other floors.
Solution:
A/ First assumption :
𝑏𝑎𝑠𝑒𝑚𝑒𝑛𝑡 𝑎𝑟𝑒𝑎 = 700 𝑚2
𝑔𝑟𝑜𝑢𝑛𝑑 𝑓𝑙𝑜𝑜𝑟 𝑎𝑟𝑒𝑎 = 700 𝑚2
1𝑠𝑡 𝑓𝑙𝑜𝑜𝑟 𝑎𝑟𝑒𝑎 = 700 𝑚2
2𝑛𝑑 𝑓𝑙𝑜𝑜𝑟 𝑎𝑟𝑒𝑎 = 700 𝑚2
𝑟𝑜𝑜𝑓 𝑎𝑟𝑒𝑎 = 700 𝑚2
𝑇𝑜𝑡𝑎𝑙 = 3500 𝑚2
∴ 𝑟𝑎𝑡𝑒 𝑜𝑓 𝑜𝑛𝑒 𝑚𝑒𝑡𝑒𝑟 𝑠𝑞𝑢𝑎𝑟𝑒 𝑜𝑓 𝑡ℎ𝑒 𝑏𝑢𝑖𝑙𝑑𝑖𝑛𝑔 =
1100000000
= 315000 𝐼𝐷
3500
B/second assumption:
𝑏𝑎𝑠𝑒𝑚𝑒𝑛𝑡 𝑎𝑟𝑒𝑎 = 0.6 × 700 = 420 𝑚2
𝑔𝑟𝑜𝑢𝑛𝑑 𝑓𝑙𝑜𝑜𝑟 𝑎𝑟𝑒𝑎 = 700 𝑚2
1𝑠𝑡 𝑓𝑙𝑜𝑜𝑟 𝑎𝑟𝑒𝑎 = 700 𝑚2
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2010-2011
2𝑛𝑑 𝑓𝑙𝑜𝑜𝑟 𝑎𝑟𝑒𝑎 = 700 𝑚2
𝑟𝑜𝑜𝑓 𝑎𝑟𝑒𝑎 = 0.4 × 700 = 280 𝑚2
𝑇𝑜𝑡𝑎𝑙 = 2800 𝑚2
1100000000
∴ 𝑟𝑎𝑡𝑒 𝑜𝑓 𝑜𝑛𝑒 𝑚𝑒𝑡𝑒𝑟 𝑠𝑞𝑢𝑎𝑟𝑒 𝑜𝑓 𝑡ℎ𝑒 𝑏𝑢𝑖𝑙𝑑𝑖𝑛𝑔 =
= 393000 𝐼𝐷 ≈ 322$
2800
𝑐𝑜𝑠𝑡 𝑜𝑓 𝑠𝑞𝑢𝑎𝑟𝑒 𝑚𝑒𝑡𝑒𝑟 𝑜𝑓 𝑏𝑎𝑠𝑒𝑚𝑒𝑛𝑡 = 0.6 × 393000 = 235800 𝐼𝐷
𝑐𝑜𝑠𝑡 𝑜𝑓 𝑠𝑞𝑢𝑎𝑟𝑒 𝑚𝑒𝑡𝑒𝑟 𝑜𝑓 𝑟𝑜𝑜𝑓 = 0.4 × 393000 = 157000 𝐼𝐷
Example:
Building of dimensions ( 40m * 60m ) , have been executed and composed of ( basement , G. floor , 1st floor
, 2nd floor ) . The height of floors is as follows:
H. for basement = 2.80m.
H. for other floors = 3.0m.
Total cost of the building is (4,000,000,000 ID).
Determine the cost of the cubic meter, using the following assumptions:
A. Cost of all floors is equal.
B. Cost of basement equal 60% of the cost of other floors.
Solution:
A/ 1st assumption:
= 40 × 60 × 2.8 = 6720𝑚3
= 40 × 60 × 3.0 = 7200𝑚3
= 40 × 60 × 3.0 = 7200𝑚3
= 40 × 60 × 3.0 = 7200𝑚3
= 28320𝑚3
4,000,000,000
=
= 141000 𝐼𝐷/𝑚³
28320
𝑣𝑜𝑙𝑢𝑚𝑒 𝑜𝑓 𝑡ℎ𝑒 𝑏𝑎𝑠𝑒𝑚𝑒𝑛𝑡
𝑣𝑜𝑙𝑢𝑚𝑒 𝑜𝑓𝑡ℎ𝑒 𝑔𝑟𝑜𝑢𝑛𝑑 𝑓𝑙𝑜𝑜𝑟
𝑣𝑜𝑙𝑢𝑚𝑒 𝑜𝑓𝑡ℎ𝑒 1𝑠𝑡 𝑓𝑙𝑜𝑜𝑟
𝑣𝑜𝑙𝑢𝑚𝑒 𝑜𝑓𝑡ℎ𝑒 2𝑛𝑑 𝑓𝑙𝑜𝑜𝑟
𝑇𝑜𝑡𝑎𝑙 𝑣𝑜𝑙𝑢𝑚𝑒
∴ 𝑟𝑎𝑡𝑒 𝑜𝑓 𝑜𝑛𝑒 𝑐𝑢𝑏𝑖𝑐 𝑚𝑒𝑡𝑒𝑟
B/ 2nd assumption:
= 0.6 × 40 × 60 × 2.8 = 4032𝑚3
= 40 × 60 × 3.0 = 7200𝑚3
= 40 × 60 × 3.0 = 7200𝑚3
= 40 × 60 × 3.0 = 7200𝑚3
= 25632𝑚3
4,000,000,000
𝐼𝐷
∴ 𝑟𝑎𝑡𝑒 𝑜𝑓 𝑜𝑛𝑒 𝑐𝑢𝑏𝑖𝑐 𝑚𝑒𝑡𝑒𝑟 =
= 156000 3
25632
𝑚
𝑣𝑜𝑙𝑢𝑚𝑒 𝑜𝑓 𝑡ℎ𝑒 𝑏𝑎𝑠𝑒𝑚𝑒𝑛𝑡
𝑣𝑜𝑙𝑢𝑚𝑒 𝑜𝑓𝑡ℎ𝑒 𝑔𝑟𝑜𝑢𝑛𝑑 𝑓𝑙𝑜𝑜𝑟
𝑣𝑜𝑙𝑢𝑚𝑒 𝑜𝑓 𝑡ℎ𝑒 1𝑠𝑡 𝑓𝑙𝑜𝑜𝑟
𝑣𝑜𝑙𝑢𝑚𝑒 𝑜𝑓𝑡ℎ𝑒 2𝑛𝑑 𝑓𝑙𝑜𝑜𝑟
𝑇𝑜𝑡𝑎𝑙 𝑣 𝑜𝑙𝑢𝑚𝑒
3. Approximate quantities :
Calculating of the approximate quantities of all general items of the work , like ( foundations , walls,
roofs , doors , D.P.C. , tiles , ceramics , sanitary services , electrical services ……etc. ), then
.multiply by the approximate rate of each item to get the approximate cost of the building .
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2010-2011
4. Modifications on the previous rates for approximate estimation:
Before calculating the approximate estimation, the previous rates should be modified in order to be
close to the existing rates therefore the following notes should be taken into consideration:
1- The specifications and properties of the previous and existing project .
2- The date of execution of the two projects.
3- The position of the two projects.
4- The general and special stipulations.
5- The composition of the building (frame or bearing wall).
6- Shape of the buildings and their heights.
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