I once worked with a contractor who told me that his strategy for making money was to search the construction documents for errors, and build them first. Then when the supervising architect found the errors, he would be paid (again) to demolish the erroneous work, and paid (a third time) to re-build it correctly.

Few contractors are so unscrupulous. But even with the best of intent, mistakes are expensive.

Building Information Modeling (BIM) is a technical strategy architects and engineers use to develop a consistent set of drawings. Many of the errors that creep into design documents have historically been the result of uncoordinated drawings. That means that when you change one drawing, it may affect others, and if you don't make changes to all the affected drawings, the documents are inconsistent and errors will result.

Because BIM is model-based, there is a single internal representation of each element of the design, with a detailed set of properties and supporting inbformation. The software is capable of developing any required drawing from this model, and changes to the model will automatically result in an update to all affected drawings.

BIM is such a good idea that some government departments now mandate that designs must be developed using BIM software. The leading BIM solutions are Autodesk's Revit, Graphisoft's ArchiCAD, and Bentley's Microstation. There are other solutions that offer some BIM capabilities, but they are less complete.

I have worked with ArchiCAD and Revit for a number of years now, and I have seen first-hand the productivity gains that BIM offers the designer, and also the reduction in documentation errors.