Quantity Takeoff information exchange (QTie)
ORGANIZATION: AACE, ASPE, RICS
Tammy McCuen, LEED AP
What is QTie?
The Quantity Take-off information exchange is the expected result of an project aimed at reducing waste in three types of problems encountered on a daily basis by cost estimators and other members of the project team.
If you talk with members of the QTie team they will tell you that when they were younger they had to take-off quantities by using a blue pencil to mark their blue prints. Since they were only issued one set of blue prints the use of the blue pencil allowed the estimator to put a check mark next to each item that was counted. These check marks would ensure that if the estimator was interrupted, then he would remember where he stopped.
Today the members of the QTie team will tell you that the biggest technological innovation encountered since they used blue prints is actually the yellow highlighter. Now drawings are electronically distributed and can be printed at will. Every estimate begins with plotting the required drawing sheets and checking off using the yellow highlighter. Once the estimate has been completed, the checked drawings are, hopefully, recycled.
During the course of a given project it has been estimated that there are over 300 individual cost estimates made of the building. Approximately 75% of the time taken during these estimates is the time required to count things in a buildings.
That's a lot of yellow highlighter ink, don't you think?
There are three different types of quantity take-offs being investigated in this project. These take-offs are progressively more complex but all start from the simple act of counting and proceed to take-offs that require the knowledge of specifications and construction methods.
- QTie for Counting. Many estimates require counting of specific unitary building components such as doors, pumps, and light fixtures. Since there are different types of each of these components, differences in the types of components need to be represented. Today, the categories of building components are often displayed in design "schedules." Some building elements require the counting of the areas to which they are applied. Any type of "covering" item falls into this second category. Examples of "covering" items include carpet, paint, wallboard finishing, and suspended ceilings.
- QTie for Quality. Once components and covering building components have been counted pricing for these components is needed. The pricing of building components is always based upon the quality of those components. Any homeowner can tell you there is a big difference between using plastic laminate or stone counter tops when doing a kitchen remodeling. Quality information is typically found in contract specifications. QTie for Quality will determine which product properties are required to distinguish differences in product quality meaningful for estimators.
- QTie for Methods. After you know the amount and quality of materials, products, and equipment being installed in the building, you may need to know how the contractor is going to build it. In some cases the construction method doesn't really matter. An example there would be installing doors. In other cases you may want to know how the contractor is going to do the work. Painting may be accomplished by some combination of brushing, rolling, and spraying. Current estimators classifications such as those found in published estimating guides often are based around the use of specific codes that, essentially, define the method of construction.
When the QTie project is complete you will be able to use QTie by including one or two sentences in contract clauses where you currently specify the delivery of estimating deliverables. QTie is an example of a project whose goal is to create non-proprietary performance-based specifications for the delivery of facility information. You will not need to include QTie in your Building Information Modeling (BIM) specifications. In fact it won't matter what technology BIM, CADD, estimating software or abacus is used. Of course those using BIM technology compliant with QTie will be able to complete their work faster and with higher quality, but use of QTie will not prohibit those continuing to manually count. It will, however, ensure that regardless who creates your estimates that YOU can use the data in those estimates without retyping or recounting.
The QTie project, like all buildingSMART alliance projects, is accomplished within the context of the Information Delivery Manual (IDM) process. This process ensures that all appropriate stakeholders participate in the requirements and results of QTie. Part of this IDM process ensures that other related projects are not reinvented as part of this project. For example the COBie2 format is already an international standard that allows the delivery of information about types and counts of materials, products, equipment, and products in an open international format and a simple to use spread sheet. The QTie project also works with the efforts of our partners at the buildingSMART international.
Who is QTie?
QTie was begun through the Association for the Advancement of Cost Engineers (AACE). In 2007 an agreement was signed between buildingSMART alliance, AACE, American Society of Professional Estimators (ASPE), and the Royal Institutue of Chartered Surveyors (RICS).
If you are an expert cost estimator, a company that produces products used by estimators, or someone who uses the results of cost estimates you can contribute to the QTie project.
QTie Challenge at Ecobuild Conference
A workshop presentation at Ecobuild in Washington, DC on December 6th 2010 brought together the ideas being developed by the QTie group with progress being made internationally.
AECOO TestBed1 QTO IDM
Construction-Operations Building information exchange by buildingSMART alliance is licensed under a Creative Commons Attribution-NoDerivs 3.0 Unported License.
Back to Information Exchange Projects