ESTIMATING

Estimating develops a total estimated cost estimate for a project. The early production of the estimate enables clients to set their budgets. Estimating supports value engineering, claims, construction bid evaluation, and funding acquisition. Various types of estimates are performed depending on project status or special requirement.

The parametric estimate (+25% to -5% accuracy) determines the economic feasibility of the project, to support design studies or trade studies by making an alternative selection process available.

The conceptual estimate (+20% to -5% accuracy) determines the approximate cost of the total project on a more defined level with higher accuracy.

The preliminary estimate (+15% to -5% accuracy) is produced at the completion of the preliminary design phase. Material takeoffs are based on preliminary design documents, partial specifications, preliminary drawings and the master equipment list.

The detail estimate (+1% to -5% accuracy) is produced near the end of the design phase to provide the client with the highest achievable accuracy of the forthcoming construction cost.

Every estimate includes a basis of estimate write-up, approved by client prior to the start of the estimate. The basis of estimate is a narrative describing the scope of the estimate, information sources and other data or factors used in developing the estimate, and any limitations that may be applicable.

Parsons uses an in-house-developed contingency analysis program based on the Construction Specification Institute divisions and subdivisions. The risk levels are determined for the cost source, design completeness, construction complexity, and service complexity for each division and subdivision item and adjust the costs accordingly.