Contractors enter the world of 3D
Which is the best method to determine quantities for a bid? To answer this question we compared two different methods for quantity determination in cooperation with a local contractor. On the one side we used a digital board together with a 2D plan to digitize the plan for use with the computer. On the other side we used a building information modeling tool (BIM) to build a 3D model in the computer and determine the quantities with the 3D model. We trained an employee in the use of the software and documented the digital lifecycle of the project. In the end we interviewed both users and asked for their comments. Although both users were beginners in the use of these tools the success was very promising. Today the company is using BIM technologies for the design of their own projects.
The pictures above show the virtual model and it's corresponding part in reality. All quantities for the bid have been taken from the virtual model. Although it is quite an effort to build the model it is without doubt a great added value for the owner, the contractor and also during the phase of use. The contractor will profit from very accurate quantities that might result in the small lead needed in order to win the bid. The owner will have a 3D model for the future that documents how the house has been designed. In bigger projects the 3D model can be used for facility management. Apart from this, in modern applications 3D parts are stored in a database which allows plenty of statistical analyses.
Building Information Modeling (BIM) - more than playing around with 3D
The picture below shows a plan that has been part of a claim. The contractor wanted to show that the quantity of excavated soil derived from the estimated amount. For this reason the contractor needed to bring in more concrete than planned which caused additional costs. With the design below the contractor was able to show the calculation of the additional amount of poured concrete - absolutely crucial for a successful claim management.
Other applications refer to the technical equipment of a building. It is much easier for craftsmen and service technicians to understand the positions of ducts, cables and hardware if the owner can provide them with a 3D picture of the whole system.
The picture from the small house shows the amount of brick stones used in this model. It helps craftsmen to quickly understand how much material is needed and where it is needed.