What are the limitations and potential problems of using a building information model to prepare an estimate?

Question

What will be an ideal response?

Answer 1

Incomplete models. Information is missing or incorrectly drawn in the model. Only components that have been accurately modeled can be used to extract accurate quantities.
2. Conflicts between the model and the construction drawings. Although the model is used to create the contract document, information may be added, deleted, or change as the model is used to create the construction drawings. Unless the contract specifically includes the model as part of the contract document the contractor is responsible for constructing the components shown on the construction drawings, even if are not shown in the model.
3. Models do not include means and methods. The contractor must take into account the means and methods when pricing a component, which may vary for individual components within a group of components. Additionally, the model often does not take into account the difficulty or problems with constructing a given component.
4. Models do not address waste. The model does not take into consideration waste inherent in the design. Inherent waste must be taken into account when preparing an estimate.