This paper presents a model for estimating the conceptual cost of reinforced concrete buildings in Qatar. The model relates building cost to building area using a parameter cost (σ) and uses a cost capacity factor (X) in an exponential model to estimate the cost of new buildings based on known building costs and areas. Values of σ and X were derived from historical building cost and area data. σ was found to decrease from 1981 to 1686 Qatari Riyals from 2002 to 2012, reflecting increasing competition among contractors. X values ranged from 0.379 to 0.856 from 2002 to 2012. Estimates using the model closely matched actual costs, validating the approach for cost estimation in Qatar.

1. International Journal of Civil Engineering and Technology (IJCIET), ISSN 0976 – 6308
(Print), ISSN 0976 – 6316(Online) Volume 4, Issue 4, July-August (2013), © IAEME
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CONCEPTUAL COST ESTIMATES FOR BUILDINGS IN QATAR
Mohammed S. Al-Ansari
Civil Engineering Department, Qatar University, P.O. Box 2713, Doha Qatar
ABSTRACT
This paper presents an analytical model to estimate the cost of reinforced concrete buildings
in Qatar. A conceptual estimate is defined in this paper as the estimate based on parameter cost ࣌
that relates building cost to building area and cost capacity factor X is an exponential model that
used to estimate the cost of new building with desired area base on a known different building cost
and area. Parameter cost ࣌ and cost capacity factor X values are derived based on buildings
historical data. A set of values of parameter cost value ࣌ and the cost capacity factor X for the state
of Qatar is developed as a result of this research paper to be used to predict and estimate the projects
costs and the required resources. Numerical results are presented to illustrate the model capability of
estimating the building cost.
Keywords: Estimation, Parameter cost, Cost capacity factor, Cost Estimate, Building, historical
Data.
INTRODUCTION
Qatar is an Arab state with Doha as its capital; it is the capital of natural gas in the world.
Qatar successful bid to host the FIFA World Cup in 2022 created a land of opportunity for
construction. Qatar is planning to invest more than 200 billion USD$ in construction projects before
the starting of the World Cup. These big projects are outside the scope of this paper; this paper will
cover the analysis of small to medium budget projects. Too many companies are trying to get a
share of the booming construction but they have to make the correct building cost estimation.
Estimating is the process of predicting project cost and the required resources. A conceptual estimate
is defined in this paper as the estimate based on parameter cost ࣌ that relates building cost to
building area and cost capacity factor X is an exponential model that used to estimate the cost of new
building with desired area base on a known different building cost and area. Developing a set of
values of parameter cost ࣌ and cost capacity factor X to be used in the state of Qatar to predict and
estimate the projects costs and the required resources is the objective of this paper. The methodology
of developing parameter cost ࣌ and cost capacity factor X consist of collecting historical data of
actual buildings from consultants offices, contracting companies and government agencies, selected
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2. International Journal of Civil Engineering and Technology (IJCIET), ISSN 0976 – 6308
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historical data are shown in Table 1. Developing parameter cost ߪ and cost capacity factor X from
the historical data through mathematical formulation. Finally, validation check of parameter cost ߪ
and cost capacity factor X is done by comparing the estimated cost with the actual cost of the
building, (1, 2, 3 and 4).
Table 1 Building Historical Data
Year Project # Building Cost
Q.R.
1$ = 3.65 Q.R.
Building Area
m2
2002 1 ૚. ૜ૠ૞ · ૚૙૟ 659
2 ૚. ૢ૜ · ૚૙૟ 902
3 ૚. ૚૟૜ · ૚૙ૠ 6112
2006 4 ૢ. ૢ૜ · ૚૙૞ 409
5 ૛. ૚૛૞ · ૚૙૟ 1012
6 ૡ. ૝ૠ · ૚૙૟ 5640
2009 7 ૚. ૞૝૜ · ૚૙૟ 816
8 ૚. ૠ૞ૡ · ૚૙૟ 951
9 ૝. ૞૟૝ · ૚૙૟ 2680
2012 10 ૞. ૟ · ૚૙૞ 354
11 ૚. ૚ૡ૟ · ૚૙૟ 766
12 ૢ. ૞૙ · ૚૙૟ 4543
Parameter Cost and Cost Capacity Factor
Parameter cost value relates the building cost to the building area:
ߪ ൌ
஼
஺
(1)
Where
ߪ ൌ Parameter Cost
‫ܥ‬ ൌ Building Cost
‫=ܣ‬ Building Area
Cost capacity factor is an exponential model that used to estimate the cost of new building with
desired area base on a known different building cost with different area:
‫ܥ‬ே ൌ ‫ܥ‬௄ ቀ
஺ಿ
஺಼
ቁ
௑
(2)
Where
‫ܥ‬ே ൌEstimated cost of the new building
‫ܥ‬௄ ൌ Known cost of the building
‫ܣ‬ே = Area of the new building
‫ܣ‬௄ ൌ Area of the known building
ܺ ൌ Cost capacity Factor
Modifying equation 2 we have:
ܺ ൌ
୪୬
಴ಿ
಴಼
୪୬
ಲಿ
ಲ಼
(3)

3. International Journal of Civil Engineering and Technology (IJCIET), ISSN 0976 – 6308
(Print), ISSN 0976 – 6316(Online) Volume 4, Issue 4, July-August (2013), © IAEME
286
RESULT AND DISCUSSION
Calculated values of the average parameter cost value ࣌ࡹ for the total building cost value
from 2002 to 2012, Table 1, Fig. 1.
Table 1 Average parameter cost value ࣌ࡹ
Year 2002 2006 2009 2012
࣌ࡹ ሺࡽ. ࡾ. ሻ 1981 1978 1809 1686
Table1 and Fig 1 show clearly that there is a drop in the cost parameter value ࣌ࡹ base on the
historical data even though the prices of material, labor charges, accommodation and everything
relates to the contracting business. There was a drop of 0.1 % between 2002 and 2006, drop of 9.0 %
between 2006 and 2009, and a drop 7% between 2009 and 2012. Drop percentages show that there is
a slim drop between 2002 and 2006, a much bigger drop between 2006 and 2009 and a somewhat
lower drop but still high between 2009 and 2012. The reason behind these drop percentages is the
increase in the number of the contracting companies to the point that they are willing to work for
zero profit to survive. The fact of the matter is that the fierce competition of the contracting
companies due to their large numbers did lead indeed to big reduction in the profits sought by the
companies. The reduction of building cost with zero profit does not necessarily mean a good chance
for the building owner because the contractor in most cases will try to make up for his losses by
lowering the building quality. The small drop percentage of 0.1 % for the years 2002 to 2006 shows
the beginning of the increase of the contracting companies in the market. The high drop percentage
of 9 % for the years 2006 to 2009 shows a huge increase in the number of the contracting companies.
For the years 2009 to 2012 the drop percentage of 7 % indicate that some companies got out of the
race, that helps the construction business to go in the right direction.
2000 2002 2004 2006 2008 2010 2012 2014
1650
1700
1750
1800
1850
1900
1950
2000
2050
Average Parameter Cost Value
Fig. 1 Years of Historical Data
AverageParameterCostValue࣌ࡹQ.R.

4. International Journal of Civil Engineering and Technology (IJCIET), ISSN 0976 – 6308
(Print), ISSN 0976 – 6316(Online) Volume 4, Issue 4, July-August (2013), © IAEME
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The cost capacity factor X values was determined using equation 3 and the historical data for
the years 2002 to 2012, Table 2.
Table 2 Cost capacity factor X
Year 2002 2006 2009 2012
ࢄ 0.379 0.602 0.853 0.856
To validate the cost capacity factor X values. The cost capacity factor for the years 2002 to
2012 X will be used to calculate the total cost of some buildings based on the historical data for the
years 2006 to 2012. The calculated values of the building total cost will be compared with actual
building total cost, Table 3.
Table 3 Estimated Total building Cost Based on Cost capacity factor X
Building Data
‫ܣ‬ே = Area of the new building
‫ܣ‬௄ ൌ Area of the known building
‫ܥ‬௄ ൌ Known cost of the building
Cost
capacity
factor
X
Building Total Cost
Q.R. ൬
۳‫܌܍ܜ܉ܕܑܜܛ‬
‫ܔ܉ܝܜ܋ۯ‬
൰ ૚૙૙
Year ࡭ࡺ ࡭ࡷ ࡯ࡷ Estimated Actual
2002 902 902 1.93 x 106
0.379 1.98 x 106
1.93 x 106
97.5
2006 905 905 1.764 x 106
0.602 1.887 x 106
1.764 x 106
93.5
2009 816 816 1.5 x 106
0.853 1.8 x 106
1.5 x 106
83.33
2012 766 766 1.186 x 106
0.856 1.238 x 106
1.186 x 106
95.8
The tabulated values of estimated and actual cost of buildings in table 3 show that the estimated cost
of the buildings based on cost capacity factor X is close to the actual cost. Therefore the cost
capacity factor X could be used to estimate the cost of new buildings in Qatar, Fig. 2.

5. International Journal of Civil Engineering and Technology (IJCIET), ISSN 0976 – 6308
(Print), ISSN 0976 – 6316(Online) Volume 4, Issue 4, July-August (2013), © IAEME
288
Fig. 2 Estimated and Actual Buildings Costs
CONCLUSIONS
A set of values of parameter cost value ࣌ࡹ and the cost capacity factor X for the state of
Qatar is developed as a result of this research paper to be used to predict and estimate the projects
costs and the required resources. The number of contracting companies must be limited; otherwise
the fierce competition of the contracting companies due to their large numbers will lead indeed to big
reduction in the profits sought by the companies. The reduction of building cost with zero profit does
not necessarily mean a good chance for the building owner because the contractor in most cases will
try to make up for his losses by lowering the building quality.
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4. Mahamid, I. (2013). “Conceptual Cost of Estimate of Roads Construction Projects in Saudi
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5. Mohammed S. Al-Ansari, “Flexural Safety Cost of Optimized Reinforced Concrete Beams”,
International Journal of Civil Engineering & Technology (IJCIET), Volume 4, Issue 2, 2013,
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