Construction Work Items’ Unit Rate Estimation Model for Building Contractors’ Projects

Pricing in Nigeria
Inuwa I. Ibrahim1, Iro A. Ibrahim1 and Dantong J. Sam2
1Quantity Surveying Programme, Abubakar Tafawa Balewa University, Bauchi-Nigeria.
2Department of Architecture, University of Jos, Plateau State, Nigeria.
E-mail: inuwaibrahimibrahim@yahoo.com
ABSTRACT: Contractors’ success amongst other things relies on how they are able to relate
and estimate the cost of their resources as a basis in determining their projects price in a
competitive market. Construction project pricing is highly exorbitant in Nigeria. Wrong methods
of estimation and flaws discovered in the unit rates of some completed building projects raises
questions on the accuracy of the cost estimates arrived at by consultant quantity surveyors.
Moreover, the discrepancy in the plethora of literatures on cost estimation makes estimation
complex and confusing. The study therefore aims at establishing a construction work items unit
rate estimation model for building contractors project pricing in Nigeria. This study uses historic
survey methods through an extensive literature search. The foremost thing to consider when
building unit rate is to establish the prime cost for each work item. Unit rate is the summation of
the prime cost, overhead charges and profit for each work items in a project. Therefore, Unit
Rate =N + (N×Z); where N-is prime cost and Z-is % overheads and profits. Mathematically; N=
MC+LC+PC. Numerical contribution of each constituent per unit of work is: Mc ≥ 0; Lc 􀀀 0; Pc ≥
0 and; Zc 􀀀 0. The model is comprehensible, its applicability is compatible with any
circumstance, it facilitates error free rates and can improve productivity. The model can be use:
for effective management of construction project; for teaching and understanding the basic
principle in rate computation and; in attaining uniformity in unit rate computation in the
construction industry.