Understanding Naming Protocols
The role of the quantity surveyor will adapt within the BIM environment. The largest difference will be the volume of detailed measurement by hand that is no longer required and will be replaced by automatic quantity take off. There are a number of software solutions that can be used for this; however, it is important for estimating software not only to have automatic take off, but also the ability to produce and link to costing documents within the same application.
It is important to group quantities by the object’s name and type.
For example, if two doors or two lengths of wall are named exactly the same then the quantities or dimensions of those objects will be grouped in the same ‘dimension group’. This is why it is so important for robust naming protocols to be agreed, so that each object should be in its correct dimension group. Furthermore, the required parameters of each object should be included within that object, as agreed within the execution plan, so that, for example, each wall will have the wall area identifiable and not just the length of wall. This is also a key point for the quality assurance check: a quick review of the dimensions will show up any obvious errors.
Another important factor is to be able to create a costing document within the software and import the quantities from the model and the rates from a database. In order to do this a library of cost items needs to be created along with associated rates so that a priced document can be built. This links in with the cost detail and LODs agreed on in the execution plan. The costing software must has provision to further interrogate (‘drill down’) levels of a cost plan, revealing increasing detail. What this creates is an elemental breakdown of items with detailed measurement, rates and costs in a level beneath that breakdown.
Once the cost plans have been established they allow for a quick update to the project costs, subject to a thorough quality assurance check. Quantities from the model and rates from the rate library are ‘live linked’ to the costing document; as such, whenever the drawings are revised, so long as the naming protocol has been followed, the cost will automatically update.